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[Display omitted] • A core-shell structured piperazine pyrophosphate microcapsules (MT@PAPP) is constructed. • The MT@PAPP enhances the compatibility and mechanical property of TPE/MT@PAPP composites. • Compared with pure TPE, the PHRR and PSPR of TPE/MT@PAPP were reduced by 78.5% and 60.0%, respectively. In this study, core-shell structured piperazine pyrophosphate (PAPP) is designed to enhance the fire safety and mechanical property of styrenic thermoplastic elastomer (TPE) composites. The PAPP is microencapsulated with carbon nanotube modified melamine-formaldehyde resin to prepare core-shell structured flame retardants (MT@PAPP). Due to the excellent compatibility between the MT@PAPP and TPE matrix, the mechanical property of TPE/MT@PAPP is improved. Compared with TPE, the peak heat release rate and peak smoke production rate of TPE/MT@PAPP are decreased by 78.5% and 60.0%, respectively. Thus, the core-shell structured piperazine pyrophosphate microcapsule strategy provides an excellent approach to obtain high-performance TPE composites. [ABSTRACT FROM AUTHOR]

In this work, microcrystalline cellulose (MCC) treated polyamide 66 (PA66) textiles were coated with green and naturally abundant polysaccharides specifically, chitosan (CS) and sodium alginate (SA) together with phytic acid (PA) via layer by layer (LbL) deposition. The prime focus of such treatment was to intensify both the hydrophilic and flame retardant properties of PA66 fabric substrates. Subsequently, the prepared coatings were further subjected to cross-linking modification by dipping them into the barium (Ba) salt solution. Obtained results indicated that the MCC-modified PA66 exhibited a water contact angle (WCA) value of 00 and revealed a drop in peak heat release rate (pHRR) up to 31 % with complete suppression of melt-dripping. Meanwhile, the Ba-ion-induced cross-linking treatment further escalated this reduction up to 36 % by adding enhanced thermal stability, improved char quality along better wash durability of as prepared coatings. In addition, the combined modification of PA66 textiles with MCC and Ba-ion handed a superb enhancement of physical properties like tensile strength by ca. 50 % compared to the pure PA66. Thus, this MCC-assisted surface modification paves the way for a new kind of greener treatment of PA66 textiles in attaining superior hydrophilic and flame retardant properties of the same. • MCC-assisted surface engineering of PA66 fabrics was done. • Green polysaccharides were deposited on PA66 surfaces in LbL assembly. • MCC-modified and LbL deposited fabric surfaces exhibited superhydrophilicity. • MCC-modified and LbL deposited showed a substantial reduction in pHHR by 36 %. • Ba ion cross-linking helped to obtain superior wash durability to developed coatings. [ABSTRACT FROM AUTHOR]

• A syringaldehyde derived epoxy resin monomer (SA-TAG-EP) was developed. • The bio-based epoxy system showed a record T g of 224 °C, high strength and modulus. • The bio-based epoxy system showed satisfactory intrinsic flame retardancy. Due to increasing environmental concerns, global warming, and the decline of oil reservoirs, the use of bio-epoxy resins derived from sustainable resources is recommended. The development of bio-based epoxy resins with considerable thermal stability, mechanical strength, and appropriate intrinsic flame retardant potential is highly demanded. In this study, a new Schiff-based epoxy monomer, triglycidyl ether of syringaldehyde (SA-TAG-EP), was synthesized from renewable syringaldehyde. After the 4,4′-diaminodiphenylmethane (DDM)-based curing process, an intrinsically flame-retardant resin (SA-TAG-EP/DDM) with C, H, N, and O elements was achieved. SA-TAG-EP/DDM showed higher glass transition temperature (224.9°C) and greater mechanical strength, including a tensile strength of 66.8 MPa and an elongation at break of 3.91%, compared to petroleum-based bisphenol A epoxy thermoset. It also passed the V-0 flammability rating in the UL-94 test and exhibited a 38.5% limiting oxygen index, 48.9% char yield under N 2 , and a lower peak heat release rate than that of petroleum-based bisphenol A epoxy thermoset. We proposed a simple and sustainable route for the synthesis of Schiff base epoxy compounds from biomass-derived resources, which demonstrates significant mechanical properties and increased flame retardant potential. [ABSTRACT FROM AUTHOR]

Cardanol-derived phenalkamines with different phosphorus oxidation states (Car-DCP-DETA and Car-DPC-DETA) were synthesized by the Mannich reaction and used as curing agents for diglycidyl ether of bisphenol A (DGEBA)-type epoxy prepolymers. 1H-NMR, 31P-NMR and FTIR spectra confirmed that Car-DCP-DETA and Car-DPC-DETA were successfully synthesized. DGEBA/Car-DCP-DETA and DGEBA/Car-DPC-DETA thermosets were fabricated by thermally induced polymerization, while DGEBA/DDM was prepared as a control sample. The curing kinetics investigation indicated that the curing activation energy of the DGEBA/Car-DCP-DETA and DGEBA/Car-DPC-DETA systems was higher than that of DGEBA/DDM because of the larger steric hindrance of Car-DCP-DETA and Car-DPC-DETA. The cone calorimetry results showed that the peak heat release rate (PHRR) values of DGEBA/Car-DCP-DETA and DGEBA/Car-DPC-DETA were 76.8% and 44.8% lower than that of DGEBA/4,4′-diaminodiphenylmethane (DDM), respectively, and the total heat release (THR) value was reduced to 125.8 and 105.8 MJ m−2, respectively, from 159.9 MJ m−2 (DGEBA/DDM). These results suggested a superior flame-retardant efficiency for Car-DCP-DETA over Car-DPC-DETA. The flame-retardant mechanisms of DGEBA/Car-DCP-DETA and DGEBA/Car-DPC-DETA were studied by thermogravimetric analysis coupled with Fourier transform infrared spectroscopy, scanning electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy. It can be inferred that the outstanding flame retardancy of DGEBA/Car-DCP-DETA is mainly ascribed to the formation of thermally stable phosphorus–oxygen structures in the combustion process, which is helpful in improving the thermal oxidation resistance of char residues and thus improving the flame retardancy of epoxy resins. Tensile and flexural test results showed that Car-DCP-DETA also had good strengthening and toughening effects on DGEBA. This phosphorus-containing cardanol-derived phenalkamine (Car-DCP-DETA) imparted simultaneously improved flame retardancy, and mechanical strength and toughness to epoxy thermosets, which could be a renewable replacement for petroleum-based curing agents in fire-resistant or corrosion-resistant coating applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • FPUF composites was formed after the introduction of Ti 3 C 2 T x @BPA@PCL and DH-DOPO. • Compression strength of FPUF-DH-Ti 3 C 2 T x @BPA@PCL are increased by 253% and is highly fatigue-resistance. • 36.1% and 44.0% reductions in pHRR and THR of FPUF-DH-Ti 3 C 2 T x @BPA@PCL are achieved. • FPUF-DH-Ti 3 C 2 T x @BPA@PCL is self-extinguished and passes the vertical burning test. It is of great importance to fabricate flexible polyurethane foam (FPUF) with superior mechanical properties and flame retardancy for practical applications. Herein, organosilicon and phenyl phosphorus compounds were synthesized and grafted on the surface of Ti 3 C 2 T x (Ti 3 C 2 T x @BPA@PCL) via in-situ polymerization. Then, the FPUF composites were fabricated, combining intrinsic flame retardancy (9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide-diethanolamine: DH-DOPO) (addition amount: 20 wt%) and Ti 3 C 2 T x @BPA@PCL (addition amount: 4 wt%). Attributed to the rigid structure of Ti 3 C 2 T x @BPA@PCL, the tensile strength and compression strength of FPUF showed 24.0% and 253% increase, respectively. In addition, anti-fatigue properties of FPUF composites during the cyclical test were dramatically enhanced. In contrast to pure FPUF, 36.1% and 44.0% reductions in peak heat release rate (pHRR) and total heat release (THR) were achieved for the FPUF containing Ti 3 C 2 T x @BPA@PCL and DH-DOPO, the production rate of carbon dioxide (CO 2) and carbon oxide (CO) also decreased by 40.3% and 52.1%, respectively. FPUF4 showed self-extinguishing behavior, and passed the vertical burning test (VBT). This work provides a facile approach to preparing high-performance FPUF with enhanced mechanical property and flame retardancy. [ABSTRACT FROM AUTHOR]

[Display omitted] Aiming at enhancing the toughness and fire safety of bismaleimide (BMI), BMI monomers containing phosphate and phosphonate structure (BDTP and BDTDP) were designed and prepared. With incorporation of 5 wt% BDTP and BDTDP, the peak value of heat release rate (PHRR) of BMI/BDTP-5 and BMI/BDTDP-5 decrease by 59.4% and 52.4%, respectively. The total smoke production (TSP) of BMI/BDTP-5 and BMI/BDTDP-5 are of 8.3% and 13.1% reduction, respectively. Meanwhile, BMI/BDTP-5 and BMI/BDTDP-5 possess UL-94V-0 rating, which indicates that BMI is endowed with better flame retardant performance by modification of designed BMI monomers. Besides, the impact strength of BMI/BDTP-5 and BMI/BDTDP-5 increase by 146.3% and 90.2%, respectively. The comprehensive performance of BMI/BDTP-5 is better than that of BMI/BDTDP-5. And the effect of phenyl phosphate structure in BDTP and phenyl phosphonate structure in BDTDP on BMI performance is explored. [ABSTRACT FROM AUTHOR]

Severe flame retardancy and poor impact resistance of epoxy resins (EPs) have become key factors limiting their industrial application. Herein, a strategy is developed to integrate nitrogen‐rich black phosphorus (BP) loaded with cerium oxide via aryl diazonium chemistry to reduce the flame risk of the EPs. Cone test results exhibit that the fire hazard of EPs containing 2 wt.% BP‐NHH‐Ce is suppressed effectively, such as that total heat release rate (THR) is reduced by 46.9%, the peak heat release rate (pHRR) is reduced by 56.2%, and the total smoke production (TSP) is reduced by 48.9%. With only 1.0 wt.% of the BP‐NHH‐Ce added, the nanocomposite can reach up to 30.5 of LOI value and simultaneously upgrade the UL‐94 rate to V‐0. In addition, the nano‐structure is beneficial to stress transfer and homogenization, which leads to significant elevation (28.2%) for the impact strength of EPs. This developed new EP/BP‐NHH‐Ce nanocomposite merits the high‐end field application of EPs. [ABSTRACT FROM AUTHOR]

• Intrinsically flame-retardant hydrogel coatings for RPUFs were developed to reduce their flammability. • RPUF composites achieved a 45% reduction in the TSP, a 27 s increase in the TTI and excellent coating adhesion. • Fire-resistant hydrogels were constructed by combining a multiscale reinforcement strategy and a flame-retardant precursor. Hydrogel, as a multifunctional engineering material, has attracted much attention for its flame-retardant applications. However, the low thermal stability of hydrogels results in the formation of a weak protective layer with weak adhesion, which limits their application. Therefore, through careful design, we successfully combined calcium phosphate nanocrosslinked points, silica nanofiber networks, and black phosphorus sheets to construct a multiscale reinforcing body. This reinforcement not only significantly improves the overall strength of the material, but also imparts excellent fire resistance properties. Furthermore, we combined this reinforcement with intrinsic flame-retardant precursors to construct a hydrogel with high fire resistance. This hydrogel coating not only effectively resists flame attacks, but also exhibits excellent mechanical properties, thus addressing the shortcomings of conventional hydrogel coatings in terms of fire resistance and mechanical properties. When used to coat RPUF materials, the hydrogel-coated RPUF composites showed a 23.6% reduction in the peak heat release rate (pHRR), a 45% reduction in total smoke production (TSP), and a 27 s extension in time to ignition (TTI). The hydrogel coating was found to be effective at inhibiting the spread of fire. In addition, the molecularly designed intrinsic flame-retardant hydrogel coating has good adhesion to RPUF and other substrates, which is sufficient for practical applications. The coatings have sustained fire protection and are suitable for a range of flame-retardant applications. This innovative design provides new ideas and methods for developing high-performance flame-retardant hydrogel coatings. [ABSTRACT FROM AUTHOR]

• A series of coatings with high transparency and excellent pencil hardness levels were prepared on polycarbonate (PC) substrates via a two-step UV-curing process with TAEP and MAAR. • The coupling effect of the combustion behaviours of the UV-cured coatings and the PC substrates was particularly investigated to give insight into a holistic picture of the combustion of the coated PC composites. • The composite UV-cured coatings successfully suppressed the heat release and improved the flame retardancy of the PC samples thanks to the phosphorus-nitrogen synergistic flame-retardant effect in the condensed phase. • A potential strategy to further enhance the flame-retardant ability of the UV-cured coatings lies in improving the thermal and mechanical stabilities of the intumescent char layers. There is an urgent demand for flame retardant treatment of polycarbonate (PC) with as little adverse impact on the inherent advantages of PC as possible, especially the high transparency. Herein, a flame-retardant coating with high transparency was successfully prepared on PC via a two-step ultraviolet-curing (UV-curing) process with tri(acryloyloxyethyl) phosphate and melamine acrylate resin. All the coated PC composites showed high transparency and excellent pencil hardness levels (6H). The coupling effect of the combustion behaviours of the UV-cured coatings and the PC substrates was particularly investigated to give insight into a holistic picture of the combustion of the coated composite systems. Specifically, all the composite UV-cured coating samples (T2M1, T1M1 and T1M2) formed highly expanded char with honeycomb-like inner structure due to the phosphorus-nitrogen synergistic effects, which could efficiently suppress mass and heat transfer, thereby protecting the PC substrates from the harsh conditions of high temperature and realizing significantly enhanced flame retardancy of the PC samples. Improving the thermal and mechanical stabilities of the intumescent carbon layers may be a practical strategy to achieve further improved flame retardant capabilities of the PC samples. Additionally, the PC-T2M1 composite exhibited the optimal flame retardant effect, realizing significantly suppressed heat release in the cone calorimeter tests, reaching UL94 V-0 rating and showing long fire resistance time thanks to the intumescent char. The UV-cured coating method introduced in this work had great potential in spawning new strategies for designing advanced flame retardant coatings for polymer substrates. [Display omitted] [ABSTRACT FROM AUTHOR]

A synergistic flame retardant with a core-shell structure utilizes the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) derivative as the outer shell and ammonium polyphosphate (APP) as the inner core. Three derivatives of DOPO (DOPO-GY, DOPO-DH and DOPO-GD) are synthesized by reacting DOPO with glyoxal, paraformaldehyde and diethanolamine, and glutaraldehyde, respectively. DOPO-GY@APP, DOPO-DH@APP and DOPO-GD@APP exhibit good radical scavenging activities. The oxidation induction time for EVA/DOPO-GY@APP is exceptionally high at 19.04 min, in contrast to EVA alone, which has an induction time of only 5.51 min. Simultaneously, after aging at 180 °C and 165 °C for 7 days, the retention rates of elongation at break for EVA/DOPO-GY@APP are 34.67 % and 55.50 %, respectively. These findings demonstrate the long-term anti-aging properties of EVA/DOPO-GY@APP without the need for additional antioxidants. Moreover, EVA/DOPO-GY@APP, EVA/DOPO-DH@APP and EVA/DOPO-GD@APP all achieve V-0 rating with 25 % addition of flame retardant. In comparison to pure EVA, their peak heat release rates and maximum smoke density decrease by 52 % and 47 %, 43 % and 54 %, and 51 % and 44 %, respectively. Additionally, compared to EVA/APP, their mechanical properties have been improved. Therefore, these microencapsulated flame retardants with DOPO derivatives as the shell effectively enhance the mechanical properties and fire safety of EVA composites. [Display omitted] • A multifunctional microencapsulated flame retardant is successfully designed. • The DOPO-GY@APP shows good radical scavenging activities. • The retention rate of EB from EVA/DOPO-GY@APP can reach 55.50 % after aging at 165 °C for 7 days. • EVA/DOPO-GY@APP reveal anti-aging properties without adding any antioxidant. • The pHRR and Ds max of EVA/DOPO-GY@APP are reduced by 52 % and 47 %, respectively. [ABSTRACT FROM AUTHOR]

• An organic-inorganic hybrid flame retardant (THPSU-MMT) was synthesized. • EP-MMT composites have good flame retardancy and comprehensive properties. • The thermal decomposition of EP-MMT composites was studied. • It provides a green and efficient method for exfoliation of montmorillonite. Traditional additive flame retardants pose issues including high dosage, easy precipitation, and poor compatibility with the matrix. Designing efficient organic-inorganic synergistic flame retardants can enhance the flame retardancy and mechanical properties of epoxy (EP) composites while reducing their smoke toxicity. In our study, we initially employed Tetrakis(hydroxymethyl)phosphonium sulfate (THPS) for intercalation modification of montmorillonite (MMT). Subsequently, we achieved a green and efficient exfoliation of MMT by reacting urea with hydroxyl groups, resulting in the simultaneous preparation of efficient organic/inorganic synergistic flame retardants (THPSU-MMT). EP composites containing 5wt% THPSU-MMT can attain UL-94 V0 classification. Furthermore, the peak heat release rate (PHRR), total heat release (THR), and peak release rates of CO can be reduced by up to 78.42 %, 62.26 %, and 72.50 %, respectively. Simultaneously, we systematically investigated the synergistic flame retardant mechanism of the EP composite. The findings reveal that THPSU-MMT exhibits a dual flame retardant effect in both the gaseous and condensed phases. Moreover, the combination of MMT and THPSU substantially enhances the presence of phosphorus-containing pyrolysis products in the condensed phase. The fire performance index (FPI) of the flame retardant EP increased from 0.05 m2/s/W in pure EP to 0.36 m2/s/W, attributed to the enhanced catalytic carbonization and assisted gas-phase free radical capture. Additionally, the flame spread index (FGI) decreased from 11.55 kW/m/s in pure EP to 1.18 kW/m/s, signifying a substantial enhancement in fire safety. Furthermore, the THPSU-MMT synergistic flame retardants improved the tensile strength of EP composites. This study offers an environmentally friendly and efficient approach for the effective exfoliation of MMT, while also presenting novel concepts for the design of efficient organic-inorganic synergistic flame retardants. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] It's known that the application of bismaleimide resins (BMI) is limited due to its brittleness and poor flame retardancy. A novel type of BMI monomer (MADQ) based on the typical phosphorus series flame retardant DOPO is designed to improve the fire safety of BMI. Besides, aliphatic long chain structure is introduced in MADQ, which is supposed to be conducive to reducing the rigidity of the BMI cross-linked network and thus to improve the toughness of BMI. It's seen that with the incorporation of 5.24 wt% MADQ, the peak of heat release rate (PHRR) and total heat release (THR) of resultant BMI/MADQ-5 is reduced by 37.7% and 33.9%, respectively. Meanwhile, with modification of 1.07 wt% MADQ, BMI/MADQ-1 possesses UL-94V-0 rating. The relevant mechanism analysis reveals that the phosphaphenanthrene group in MADQ can exert flame retardancy effect both in condensed and gas phase. Besides, the impact strength of the BMI/MADQ is maximally increased by nearly 90.1%. Furthermore, the BMI/MADQ still maintains high tensile strength and thermal stability, which indicates the modification of MADQ did not deteriorate other properties of BMI. An innovative research idea and research basis for the preparation of intrinsic flame-retardant and toughened BMI is provided in this work. [ABSTRACT FROM AUTHOR]

[Display omitted] Polyolefin (PO) cables used in confined spaces need to have low smoke, low heat release, low toxic gas release and excellent physical properties. In this work, a series of rare earth stannates Re 2 Sn 2 O 7 (RES, Re = Nd, Sm, Gd) with high temperature catalytic performance were prepared by hydrothermal method for synergistic flame retardant PO/IFR. The flame retardancy, heat release, smoke density, toxic gas release and physical properties of PO composites were thoroughly studied in detail. The RES could enhance the vertical burning rating and the limiting oxygen index (LOI) of PO/IFR composites. Moreover, the residual char of the thermogravimetric analysis increased from 9.7% to 11.4 wt% after the RES added in PO/IFR system. Interestingly, the PO/IFR system containing Gd 2 Sn 2 O 7 exhibits the lowest peak heat release rate of 233.7 kW/m2. Excellent flame resistance due to the formation of a complete and compact protective char layer. In addition, the toxic release of PO during combustion is also effectively reduced by introducing the RES. The tube furnace combustion test shows that the emission of carbon oxide (CO) and hydrogen cyanide (HCN) of PO/IFR/Gd 2 Sn 2 O 7 are the lowest. It can be attributed to the catalytic effect of rare earth elements and the blocking effect of the dense char layer. In addition, compared with the PO/IFR composites, the PO/IFR/RES system demonstrate higher mechanical properties and volume resistivity. Therefore, the addition of RES has a positive effect on improving the physical properties and fire safety properties of the PO/IFR cable composites, especially suitable for using in confined spaces. [ABSTRACT FROM AUTHOR]

[Display omitted] • ZIF-8@Ti 3 C 2 T x was synthesised and applied to prepare flame-retardant flexible polyurethane foam composites. • Flame-retardant flexible polyurethane foam composites displayed excellent heat and toxic gases suppression performance. • Flame-retardant flexible polyurethane foam composites showed notable mechanical properties during compression and tensile tests. • The flame-retardant mechanism of ZIF-8@Ti 3 C 2 T x was systematically explored through gas and condensed products. Flexible polyurethane foam (FPUF) is the most used polyurethane, but the highly flammable characteristic limits its widespread usage. In this work, ZIF-8@Ti 3 C 2 T x was synthesized to reduce the heat and toxic gases of FPUF. Flame-retardant FPUF was characterized by cone calorimeter (Cone), thermogravimetric analysis/fourier-transform infrared spectroscopy (TG-FTIR), tensile and compression tests. Compared with pure FPUF, these results showed that the peak of heat release rate (PHRR), total heat release (THR), CO and HCN of FPUF6 decreased by 46%, 69%, 27% and 43.5%, respectively. Moreover, the tensile and compression strength of FPUF6 demonstrated a 52% and 130% increment, respectively. The superior dual metal catalytical charring-forming effect and physical barrier effect of ZIF-8@Ti 3 C 2 T x were achieved. In summary, a simple and reliable strategy for preparing flame-retardant FPUF with reinforced mechanical and fire safety properties was provided. [ABSTRACT FROM AUTHOR]

[Display omitted] • The free switch of passive radiation cooling and solar thermal conversion is realized. • An average temperature drop of ∼5.62 °C is achieved under the hot environment. • A temperature increase of 28.3 °C is achieved under the cold environment. • The fire hazards of materials designed are suppressed significantly. Seasonable and spontaneous replacement approach of daytime radiative cooling to solar thermal conversion is challenging yet imperative for year-round thermal management materials. Meanwhile, the fire safety of thermal management materials is extremely important but often overlooked. Herein, we report a bio-inspired and fireproof aerogel presenting dynamically self-switchable ability of daytime radiative cooling and solar thermal conversion, composed of thermochromic microcapsules (TC), boron nitride nanosheets (BN), and bio-based materials (alginate and phytate). In hot environments, TC/BN composite aerogel shows solar reflectivity of 91.8 % and IR emissivity of 84.3 %, promoting heat radiation to outer space and achieving an average temperature drop of ∼5.62 °C. Attributed to the thermochromic mechanism, TC/BN composite aerogel can harvest visible light of 87 % in the solar spectrum to increase the material temperature by 28.3 °C, under an environment of −8.8 °C. Based on the EnergyPlus simulation, the employment of TC/BN composite aerogel contributes to decreasing the energy consumption of buildings in both hot and cold regions, including Cairo, Singapore, Alaska, Yakutsk, and so on. Besides, the peak values of heat release rate and total heat release during the combustion of TC/BN composite aerogels are significantly decreased by 70.6 % and 58.4 %, compared to those of TC composite aerogel. The produced protective char layer enhanced by BN nanosheets is capable of isolating the fire and suppressing the fire propagation, improving the fire safety of composite aerogels designed. The TC/BN composite aerogels provide a smart thermal regulation mode for radiative cooling and solar heating, overcome the problems from changing weather and environment, and significantly promote the practical application by enhanced fire safety. [ABSTRACT FROM AUTHOR]

Epoxy resin (EP) is quite flammable, which limits its application in areas such as coatings and electronic and electrical materials. In this study, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) (or diphenylphosphine oxide (DPO)) 3-cyclohexene-1-formaldehyde (CC) and 4,4'diaminodiphenylmethane (DDM) were selected for the synthesis of two rich aromatic and phosphorus-containing compounds (DOPO-CC and DPO-CC). DOPO-CC and DPO-CC were introduced into epoxy pre-polymers to prepare epoxy thermosets with flame retardancy. When 5 wt% DOPO-CC (P content of 0.50 wt%) or DPO-CC (P content of 0.52 wt%) was added, the LOI values of the epoxy thermosets increased from 25.5% (pure EP) to 33.5% (EP added DOPO-CC) and 31.0% (EP added DPO-CC), respectively, and these epoxy thermosets also achieved the UL-94 V-0 rating. Additionally, cone calorimeter tests showed that the peak heat release rate (PHRR) and total heat release (THR) of epoxy thermoset containing 5 wt% DPO-CC reduced by 42.0% and 39.7% compared to those of pure EP, respectively. By reducing the thermal degradation rate (condensed phase) and combining and quenching free radicals (gaseous phase), the introduction of DOPO-CC or DPO-CC can efficiently improve the flame retardancy of epoxy thermosets. More importantly, the epoxy thermosets containing DOPO-CC or DPO-CC exhibited better mechanical properties than pure EP, which could be proven by the storage modulus and tensile strength. This study provided a new class of rich aromatic and phosphorus-containing compounds that can serve as co-curing agents for epoxy thermosets with outstanding comprehensive performances. [Display omitted] • Two rich aromatic and phosphorus-containing compounds (DOPO-CC and DPO-CC) were synthesized. • EP containing 5 wt% DOPO-CC or DPO-CC showed UL-94 V-0 level. • The PHRR and THR of EP containing 5 wt% DPO-CC decreased by 42.0% and 39.7%, respectively. • EP containing DOPO-CC or DPO-CC exhibited better mechanical properties than pure EP. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cardanol was applied to capture excess carbon dioxide from industry. • The bio-based NIPUs were synthesized from cardanol and carbon dioxide. • The comprehensive improvement effect of +5 valence of P was better than that of +3. • The modification of the intrinsic structure achieved eminent adhesion performance. Under the background of fossil fuel depletion and global warming, the large amount of carbon dioxide (CO 2) produced by industrial production was a renewable, clean and natural C1 feedstock that was becoming an ideal feedstock to produce value-added chemicals. The synthesis of non-isocyanate polyurethanes (NIPU) from cyclic carbonates as intermediate products was a typical way to realize the efficient recycling of CO 2. To improve the low carbonization, flammability and poor mechanics of NIPU and expand its application scenarios, the NIPU was synthesized from biological cardanol and CO 2 by a relatively green synthesis route, and modified by flame retardants containing different valence phosphorus. Compared with ECH-CarCO 2 -HMDA, the char residue of PO-CarCO 2 -HMDA and PP-CarCO 2 -HMDA increased by 248.8 % and 172.7 % respectively under nitrogen atmosphere, and 345.7 % and 151.9 % respectively under air atmosphere. More importantly, the peaks of heat release rate of modified NIPUs were reduced by 30.0 % and 18.4 %, and their total heat release were decreased by 15.2 % and 10.4 %, respectively. After various characterization analysis, this was mainly due to the generation of heat-stable structure containing phosphorus and oxygen during the burning process. Simultaneously, the toughness of PO-CarCO 2 -HMDA and PP-CarCO 2 -HMDA increased by 261.0 % and 105.1 %. In addition, the synthetic NIPU as an adhesive in different materials was also explored, and the adhesion strength can reach 2.47 MPa. This study provided a new idea for preparing bio-based NIPU which was more widely used. [ABSTRACT FROM AUTHOR]

[Display omitted] As an antioxidant, hindered phenol scavenges free radicals. Due to the oxidative degradation of black phosphorus (BP) in the presence of water and oxygen, free radical quenching of hindered phenol antioxidants can solve this issue and improve the environmental stability and flame retardant efficiency of BP. Herein, hydroxyl-modified BP (BP-OH) with active groups on the surface was obtained by hydroxylation, and then the hindered phenol antioxidant was grafted onto the surface of BP-OH through an isophorone diisocyanate bridging covalent reaction to obtain hindered phenol-modified BP (BP-HPL). The fire hazard of thermoplastic polyurethane (TPU) can be significantly reduced by introducing BP-HPL into TPU. Adding 2 wt% BP-HPL can reduce the heat release rate and total heat release values of TPU by 49.9% and 49.0%, respectively. In addition, the reductions in smoke volume and carbon monoxide production were also significant. Compared with BP-OH, the environmental stability of BP-HPL is significantly improved. This work provides a reference for the application of BP in the field of fire safety and simultaneously achieves the improvement of the environmental stability and flame retardant performance of BP. [ABSTRACT FROM AUTHOR]

[Display omitted] • Three kinds of flame retardant with different phosphorus content were synthesized. • MPBT exerted the best synergistic flame retardant effect. • The dual-phase flame retardant mechanism was analyzed in detail. • Tensile strength of flexible polyurethane foam was improved to a large extent. Herein, three different phosphorus-containing compounds (methyl phosphoryl dichloride, phenyl phosphoryl dichloride and phenyl dichlorophosphate) were reacted with 2-aminobenzothiazole respectively, and a series of synergistic flame retardants with phosphorus, nitrogen and sulfur elements were synthesized, named MPBT, PPBT and POBT respectively. Then, they were added to prepare flame-retardant flexible polyurethane foam (FPUF). Through the analysis of thermal stability, pyrolysis, heat release and smoke release behavior, the influence of different phosphorus-containing structures on the flame-retardant performance of FPUF was studied, and their flame-retardant mechanism was explored in detail. Among them, MPBT had the highest flame retardant efficiency with the same addition amount (10 wt%). The limiting oxygen index (LOI) value of PU/10.0% MPBT reached 22.5 %, and it successfully passed the vertical burning test. Subsequently, the addition amount of MPBT was increased and the best comprehensive performance of flame-retardant FPUF was explored. The results showed that the LOI value of PU/15.0% MPBT was increased to 23.5%. As for PU/15.0% MPBT, the peak heat release rate (PHRR) was 453 KW/m2, which was reduced by 46.64 %; and the flame retardancy index (FRI) value was also increased to 6.88. At the same time, the mechanical properties of flame-retardant FPUF were studied. The tensile strength of PU/15.0% MPBT reached 170 KPa, and the permanent deformation of FPUF/10% MPBT was only 4 %, showing its excellent resilience. The above results show that this phosphorus-containing element hybrid synergistic flame retardant (MPBT) has a very good application prospect in the field of flame-retardant polymer materials. [ABSTRACT FROM AUTHOR]

A SiO 2 based polymeric composite coating is developed via a facile strategy to get fire resistance for wooden materials. The composite coatings exhibit strong interfacial adhesion to versatile flammable substrates. The coating-treated wood features well flame resistance, a high LOI of 48.0%, a desired V-0 rating during vertical burning, low heat release rate and long ignition time. [Display omitted] Fire resistant coatings have been proven as an efficient way to improve fire safety in three aspects: reducing the Heat Release Rate (HRR), delaying the ignition time and preventing heat transfer. Herein, a SiO 2 based polymeric composite coating with a lower thermal conductivity and brilliant fire resistance was developed. Isocyanate and sodium silicate could form the final Si-O-Si network structure by polymerization. Compared to the wood without coating, the coated wood shows a significantly increase in limit oxygen index (LOI), has reached 48.0 vol% in the test. As for the cone calorimetry test, coated wood shows a 55.3% decrease in the first peak Heat Release Rate (pHRR) and the Total Heat Release (THR) obtains fire-resistant standard. After exposed to butane flame for 30 mins, the coated wood could still maintain its structural integrity with only 180℃ on the non-exposed side. The commercial standard test of the coating was also investigated. To better understand what role does the polyurea play in the system, a theoretical calculation was done during the research to discuss the interaction between the silica and polyurea. As a fast brush-formed coating, it exhibits a great potential in the field of fire-resistant materials, and may broaden the application prospects of wood. [ABSTRACT FROM AUTHOR]

[Display omitted] A sandwich-like melamine/phytic acid/silicon nitride hybrid (SW-Si 3 N 4) sheets were prepared by supramolecular wrapping as the hybrid flame retardants for thermoplastic polyurethane (TPU). The introduction of Si 3 N 4 sheets as a template could not only induce the generation of two-dimensional phytic/melamine (PAMA) capping layers, but also produce the synergistic flame-retardant effect on TPU composites. Cone test showed that heat release rate (HRR), smoke production rate (SPR) and total smoke production (TSP) values of TPU were decreased obviously by adding SW-Si 3 N 4. TG-IR test indicated the dramatic inhibition of aromatic compound, hydrocarbons, CO and HCN release. Besides, the thermal conductivity of composites was obviously improved by adding SW-Si 3 N 4. This work may provide better reference for developing multi-functional TPU composites for diverse application. [ABSTRACT FROM AUTHOR]

[Display omitted] • FPUF with EMIshielding performance were prepared via electroless plating SNPs. • The EMI SE accomplished 62 dB when decorated for 1 h and reached 120 dB after 2 h. • The SSE/t was 2434.00 dB·cm2/g, far satisfying the commercial request. • The PU foam exhibited anti-dripping behavior and the HRR reduced 80.92%. • CO decreased by 75.01% and other typical toxic gases (HCN, etc.) were also reduced. Flexible polyurethane foam (FPUF) has been considered as an excellent material in many fields, such as furniture and electromagnetic interference (EMI) shielding products due to its lightweight and flexibility. However, there is a severe fire hazard problem for FPUF that makes it unsuitable to be used in practical. Herein, a facile method was to prepare anti-dripping FPUF via electroless plating at ambient temperature. The silver nanoparticles (SNPs) were in-situ grown on the surface along with the polydopamine (PDA) as an adhesive and template (SNP@PDA@FPUF). As a result, these FPUFs show outstanding fire safety and anti-dripping capacity, and the heat release rate reduced 80.92%. Furthermore, the amounts of carbon oxide (CO) and carbon dioxide (CO 2) decreased 75.01% and 22.4%, respectively. Above all, the EMI shielding effectiveness (SE) accomplished almost 120 dB as the increasing electroless time with a low density of 0.051 g/cm3. Furthermore, the specific EMI SE (SSE) and the absolute EMI SE (SSE/t) accomplished 2630.98 dB·cm3/g and 2434 dB·cm2/g, respectively, which was far beyond the commercial request. Therefore, this work may provide a facile way to prepare low density and EMI shielding products with high fire safety for next generation electronic products. [ABSTRACT FROM AUTHOR]

[Display omitted] Although more and more attention has been paid to electromagnetic interference (EMI) shielding fabric materials due to increasing electromagnetic waves pollution, little attention to their fire safety behavior and durability in practical use. Herein, durable EMI shielding ramie fabric with flame retardant and self-healing performance were fabricated by depositing ammonium polyphosphate (APP)/polyethyleneimine (PEI) layer, MXene sheets and polycaprolactone (PCL) layer. The resultant multifunctional fabric could self-extinguish and the peak heat release rate (pHRR) value reduced about 74.3% for the modified ramie fabric that contains about 12 wt% of PEI/APP bilayer compared with pure ramie fabric. Furthermore, the ramie fabric coated by a increasing amount of MXene sheets changed from insulating to conductive, thus gradually improving their EMI shielding performance, which exhibit a high electrical conductivity of 900.56 S/m with an outstanding SE value of 35 dB at a 1.2 mg/cm2 content in the X-band. Besides, When the multifunctional fabric was cut off under external force, it could achieve self-healing and the EMI shielding performance can recover to 34 dB due to the low melting point and good fluidity of PCL. Thus, this multifunctional fabric holds great promise for wearable intelligent cloth, EMI shielding and other fields. [ABSTRACT FROM AUTHOR]

The composites based on ethylene–vinylacetate copolymer (EVA) and β-FeOOH, MoO3, or Sb2O3were prepared through a melt blending process.Apart from MoO3, the nanoparticles homogeneously dispersein the EVA matrix. In thermogravimetric analysis (TGA), EVA/5%MoO3and EVA/5%Sb2O3exhibit an enhancedthermal behavior at initial temperatures. However, β-FeOOH onlycan improve the thermal behavior of EVA at high temperatures. Theglass transition temperature (Tg) andthe storage modulus are all raised with the addition of β-FeOOH,MoO3, or Sb2O3. According to a conecalorimeter (CONE), the addition of these oxides brings an efficientreduction of the flammability parameters, such as peak heat releaserate (PHRR), total heat release (THR), peak smoke production rate(PSPR), total smoke production (TSP), peak carbon monoxide productionrate (PCOR), and so on. Laser Raman spectroscopy (LRS) and thermogravimetricanalysis-Fourier transform infrared spectrometry (TGA-FTIR) revealthe cause of the retarding combustion and smoke suppression of β-FeOOH,MoO3, or Sb2O3in EVA matrix. [ABSTRACT FROM AUTHOR]

A novel natural material-based flame retardant melamine chitosan phosphate (MPCS) has been prepared. Its impact on thermal properties and flammability performance of polyvinyl alcohol (PVA) was analyzed. Thermogravimetric analysis data exhibited that MPCS enhanced the thermal stability of materials at high temperature. The results of thermogravimetric analysis/infrared spectrometry (TGA-IR) showed that MPCS decreased the yield of flammable volatilized products greatly. Microscale combustion calorimetry (MCC) data showed that peak heat release rate (PHRR), total heat release (THR) and heat release capacity (HRC) all reduced, which indicated that MPCS improved the flame retardancy of materials. [ABSTRACT FROM AUTHOR]

A carbohydrate compound originated from plant species, namely oxidized sucrose (OS) was used as a cross-linking agent to stabilize the layer by layer (LbL) deposited flame retardant coatings developed onto the polyamide 66 textile surfaces. Here, the coating was constructed using some polyelectrolytes like chitosan (CS), sodium alginate (SA), phytic acid (PA) and montmorillonite (MMT) derived from green and mineral sources in a LbL assembly and subsequently, this coating was further treated with a polysaccharide binder like starch and a cross-linking agent like OS. In line, another bio-derived cross-linker, namely citric acid (CA) was used instead of OS and compared herewith. Obtained results showed that OS revealed superior coating stability over CA and in line, OS treated PA66 textiles exhibited better flame retardancy compared to the CA treated one. For example, OS treated fabrics attained a maximum limiting oxygen index (LOI) value by 23.5% along with a significant reduction in the peak heat release rate (pHRR) and total heat release rate (THR) by 36% and 15%, respectively. Meanwhile, OS could improve the stability of such coatings and offer extended durability in flame retardant performance. Thus, it was revealed that oxidized sucrose exhibited its potential to be considered as an effective green flame retardant alongside its cross-linking ability. [Display omitted] • O-Sucrose (OS) and citric acid (CA) were used to stabilize the LbL coating. • O-Sucrose provided better coating stability and flame retardancy than citric acid. • Green polyelectrolytes like chitosan and sodium alginate were used in LbL assembly. • The pairing of phytic acid with OS handed a substantial reduction in pHRR by 36%. • O-Sucrose treated PA66 could retain UL-94V1 rating even after 10 laundering cycles. [ABSTRACT FROM AUTHOR]

The demand for "green" materials increases due to concerns about the effects of flame-retardant textiles. Using natural plant-base compounds such as phytic acid (PA) and the most abundant green amino polysaccharide chitosan (CS) as effective and durable flame retardants for textiles is essential for creating sustainable and ecological textile products. This study aims to develop a novel, eco-friendly, phosphorus- and nitrogen-containing flame retardant known as ammonium phytate (AP), intending to improve the flame retardant properties of polyamide 6.6 (PA6.6) textiles. UV-induced grafting with 2-acrylamide-2-methylpropane sulfonic acid (AMPS) increases the surface functional groups of PA6.6 fabrics. Later, the surface-modified fabrics were coated with phosphorus-containing heteroatom-based components, namely, sulfur, nitrogen, silicon, and boron, onto a single flame retardant system via layer-by-layer (LBL) deposition of positively charged chitosan/boron drop (3-aminopropyl) triethoxysilane/silicon dioxide (CS/BAPTES/SiO 2) sole solution and negatively charged AP solution to enhance superior hydrophilic and durable flame retardant performance. According to the data, a weight pick-up of 56.5% is attributable to only 4 BLs. However, all the flame-retardant-coated fabrics can completely stop the melting-dripping tendency and achieve B-3 to B-2 ratings after the UL-94 vertical burning test. In addition, the LOI values of treated fabrics increase from 18.5% to 23.5% compared to a pure sample. The AMPS grafted with a 4BL-deposited fabric sample exhibits a maximum decrease in peak heat release rate (PHRR) of more than 54%. Moreover, the thermogravimetric analysis (TGA) test reveals a significant increase in thermal stability and char yield. Additionally, the as-prepared phosphorus-containing heteroatom-based coatings impart a water contact angle value of approximately 0⁰ within 2 s, demonstrating that the treated fabrics exhibit superior hydrophilic performance. Moreover, using AMPS-grafted and only 2-BL-deposited treatments improves coating stability in washing and imparts durable flame retardancy that can resist up to 20 washing cycles. It is proposed that the sustainable phosphorus-containing heteroatom-based coating may be a potentially effective replacement for existing durable flame retardants routinely used in textile finishing operations. [Display omitted] • UV-induced grafting of AMPS onto the PA6.6 fabric surfaces was done. • A P-containing heteroatom-based coating was applied successfully. • A maximum reduction in PHRR of over 54% was realized in only 4BL-deposited fabric samples. • An improvement in the superior hydrophilic fabric surfaces was attained. • Only 2 BLs of finishing treatment could stop the melt-dripping tendency even after 20 washing cycles. [ABSTRACT FROM AUTHOR]

• The smart fabric cotaing was prepared using a one-step process. • A solid, fire-resistant gel serves as the host skeleton. • A solid–liquid switchable phase change functional guest. • The fabric effectively responds to changes in ambient temperature. The stability of personal thermal management are increasingly indispensable in modern society due to the growing demand for energy savings and environmental protection. Herein, inspired by solid–liquid host–guest materials, we propose a coating preparation strategy that uses a solid flame-retardant gel as the host skeleton filled by a solid–liquid switchable phase change flame-retardant functional guest, thus fabricating smart polyester fabrics for personal temperature management in one step. Both attenuated total reflectance (ATR) and scanning electron microscopy (SEM) are used to confirm the host–guest structure coating on the surface of polyester fabric. Results from simulated cold and heating environments show that the coated polyester fabric has a desirable personal temperature regulation ability. The skin wrapped by the coated polyester fabric presents a higher temperature compared with bare polyester fabric, in simulated cold conditions. Meanwhile, in heating conditions, the internal temperature of the coated polyester fabric is 5.2 oC lower than that of the bare polyester fabric. Furthermore, the coated polyester fabric exhibits excellent flame retardancy in the combustion test, with a horizontal burning rate of 85.7 mm/min and a peak of heat release rate (PHRR) reduction of 52.8 %, attributed to higher graphitization degree and suppressed pyrolysis products. For promoting the practical application, the water vapor transmission, washing resistance, and mechanical performance are also deeply studied. Hence, a phase-change flame-retardant polyester fabric constructed with a host–guest structure provides huge application potentials in various personal temperature management fields, such as snow rescue, field camping, and adventure activities. [ABSTRACT FROM AUTHOR]

• A simple sol-gel method is employed to modify the surface of ZrP nanosheets. • EP/IFR/OZrP composite successfully pass UL94 V0 rating and obtain LOI of 44. • The impact strength of EP/IFR/OZrP composite is effectively improved. Even though the incorporation of zirconium phosphate (ZrP) nanosheets can enhance fire safety of epoxy (EP) resin, the sole addition of ZrP nanosheets cannot make EP resin pass the UL94 V0 rating and obtain high limit oxygen index (LOI). Meanwhile, traditional intumescent flame retardants (IFR) also deteriorate the mechanical properties of EP/ZrP composites. Herein, for optimizing fire safety and mechanical property, organically modified ZrP (OZrP) nanosheets are prepared based on simple sol-gel chemistry and further combined with IFR to enhance the overall performance of EP composite. Compared to LOI values of pure EP (25) and EP/IFR composite (38), incorporating 2.0 wt% OZrP nanosheets further increase LOI to 44. Meanwhile, EP/IFR/2.0 wt% OZrP composite successfully pass the UL94 V0 rating at the thickness of 0.8, 1.6, and 3.2 mm. As expected, the deterioration of mechanical performance of epoxy resin caused by the addition of IFR is obviously suppressed by introducing OZrP nanosheets, confirmed by impact strength of up to 12.7 kJ/m2 of EP/IFR/3.0 wt% OZrP composite. In the cone calorimeter test, the combination of 2.0 wt% OZrP and 20.0 wt% IFR significantly decreases the peak value of heat release rate and total heat release of EP resin by 83.9 % and 59.7 %. According to the microstructure and chemical composition of char residue, an intumescent and graphitized char formation mechanism is raised for the significantly enhanced fire safety in EP/OZrP/IFR composites. The optimization effect of OZrP nanosheets in the fire safety and mechanical property of epoxy/intumescent flame retardant composites further promote the practical application of epoxy resin. [Display omitted] [ABSTRACT FROM AUTHOR]

With the growing awareness of global warming and depletion of petroleum resources, the development of bio-based epoxy thermosets as an alternative to petroleum-based diglycidyl ether of bisphenol A (DGEBA) epoxy thermosets has generated extensive interest over the past decade. However, most of the bio-based epoxy thermosets studied to date are bio-based epoxy monomers or bio-based curing agents. In order to increase the biomass content in the resultant epoxy thermoset as high as possible, it is desirable to fabricate fully bio-based epoxy thermosets. In this study, we synthesized a bio-based epoxy monomer (SA-GA-EP) from syringaldehyde, as well as a bio-based curing agent (DIFFA) from furfurylamine. The fully bio-based epoxy thermoset was obtained through curing SA-GA-EP by DIFFA, while the commercial DGEBA epoxy thermoset was cured by 4,4′-diaminodiphenylmethane (DDM) as a contrast sample. The glass transition temperature (Tg) of the cured SA-GA-EP/DIFFA thermoset was as high as 204 °C, which was much higher than that of the DGEBA/DDM thermoset (143 °C). The tensile strength and elongation at break of SA-GA-EP/DIFFA were 57.4 MPa and 2.9%, respectively, which were comparable to those of DGEBA/DDM. Additionally, the cured SA-GA-EP/DIFFA thermoset displayed excellent intrinsic flame retardancy with UL-94 V-0 classification and a relatively high limiting oxygen index of 40.0%. The results of the cone calorimetry test also manifested that the peak heat release rate, the total heat release and the smoke production rate of SA-GA-EP/DIFFA significantly declined by 85%, 86% and 38%, respectively, compared to those of DGEBA/DDM. Moreover, bio-based epoxy exhibited antibacterial activities against Gram-positive S. aureus. Owing to these outstanding performances (including mechanical strength and modulus, high Tg, intrinsic flame resistance and antibacterial properties), this fully bio-based epoxy thermoset is a green and promising substitute for DGEBA-based thermoset in high performance fire safe applications. [ABSTRACT FROM AUTHOR]

A plant derived bio-macromolecule namely lignin (L) and a green phosphorus compound like phytic acid (PA) were functionalized with graphene oxide (GO) and subsequently, used to enhance the flame retardant properties of polyamide 66 (PA66) fabrics in a one pot deposition method. Meanwhile, we also considered pure phytic acid and one more bio-derived charring agent like chitosan (CS) to formulate a series of GO-based flame retardant finishing by altering the applied compounds in the formulation. The applied finishing with a minimum loading % (i.e., less than 10%) rarely altered the physical properties (i.e., color, handle and tensile strength, etc.) of treated textiles while provided enhanced thermal stability and added flame retardancy. Thus, a significant increase in limiting oxygen index (LOI) by 27% was received for the GO-lignin and GO-phytic acid modified fabric sample (i.e., PA66-A), indicating the supremacy of graphene-based compound. Furthermore, a substantial reduction in the peak heat release rate (pHRR) by 25% was also noticed for the fabric sample treated with GO-lignin, chitosan and phytic acid (i.e., PA66-D). Additionally, the as prepared finishing exhibited a considerable level of wash durability as a maximum reduction of pHRR by 17% was retained even after 5 washing cycles. Unlabelled Image • GO-functionalized biomolecules were used in developing flame retardant PA66 fabric. • This treatment rarely altered the color, handle and tensile strength of PA66 fabric. • GO-lignin and GO-phytic acid treated PA66 fabric received a LOI of 27%. • PA66 treated with GO-lignin, chitosan and phytic acid showed 25% pHRR reduction. • These flame retardant and thermally stable coatings were wash-durable as well. [ABSTRACT FROM AUTHOR]

For improving the flame retardancy of epoxy resin (EP), β‐cyclodextrin@ ferrocene@hollow mesoporous silica microspheres (β‐CD@FE@HMS) were prepared successfully by the self‐assembly method. Then, they were used as flame retardant to improve the fire safety of EP. EP/β‐CD@FE and EP/HMS composites were also prepared for comparative study. The results showed that β‐CD@FE@HMS could effectively improve the thermal stability of EP, in which the initial degradation temperature and the amount of char residue of EP were increased. The content of small molecule toxic gases produced by the combustion of EP composite was also reduced apparently. With the addition of 5 wt% β‐CD@FE@HMS, LOI value of EP was increased to 27.5% from 19.8%, and UL‐94 reached V‐1 rating. Comparing with pure EP, the peak heat release rate and total heat release values of EP were reduced by 11.0% and 12.3%, respectively, and the total smoke production was reduced by 30.6%. EP/β‐CD@FE@HMS composite formed a higher quality char layer. Therefore, β‐CD@FE@HMS microspheres could improve the fire safety of EP. [ABSTRACT FROM AUTHOR]

Chitosan (CS) and phosphorylated chitosan (PCS) were deposited onto the polyamide 66 (PA66) fabric surfaces along with poly-acrylate sodium (PAS) via 'one pot' and layer by layer (LbL) assembly methods in preparing flame retardant coatings. Subsequently, to stabilize the deposited coatings, some of the fabric samples were treated under the UV-irradiation and additionally, a thermal treatment was also carried out for the remaining fabric samples. The LbL assembled fabrics showed a better homogeneity in the coating structure over the one pot deposited fabrics as appeared in scanning electron microscopy (SEM). Nonetheless, the LbL treated fabric sample (i.e., PA66-10BL-UV) with a higher weight gain% exhibited a greater improvement in limiting oxygen index (LOI) (i.e., 23%), and a reduced peak heat release rate (pHRR) (i.e., 25%). Yet more, only the LbL assembled and thermally cross-linked fabric sample could able to retain the flame retardant behavior in the vertical burning test even after 5 washing cycles. • A flame retardant coating for PA 66 textiles was developed from chitosan polymers • Coatings were constructed via one pot deposition and layer by layer assembly method • LbL assembled coatings exhibited a better homogeneity over one pot deposition • A maximal reduction of 25% in pHRR was achieved for LbL assembled fabric sample • LbL assembly showed superior flame retardancy over one pot deposited fabric samples [ABSTRACT FROM AUTHOR]

Simultaneous flame retardancy and tensile strength enhancement of poly(lactic acid) (PLA) is particularly important due to its eco-friendliness and potential application as an engineering plastic. This work investigates the application of azo-boron (AZOB) modified reduced graphene oxide (RGO) intercalated by sodium metaborate (SMB) for simultaneous flame retardant (FR), smoke/toxic fumes suppression and tensile strength enhancement of PLA nanocomposites. The RGO-AZOB/SMB hybrid was prepared by aryl grafting of AZOB on GO followed by in-situ reduction/intercalation with sodium borohydride/SMB. Then RGO-AZOB/SMB hybrid was incorporated into PLA, and the properties were examined. Cone calorimeter test demonstrates improved FR performance by substantial reductions in peak heat release rate ∼76.5%, total heat release ∼76.9%, total smoke release ∼55.6%, peak CO production ∼25.9% and peak CO 2 production by ∼78.6%. A V-0 rating was attained in the UL 94 test with a higher LOI value of 31.2%. Considerable reductions in pyrolysis products, mainly hydrocarbons, CO, CO 2 , and carbonyl compounds were observed. The tensile strength and Young's Modulus were improved by 49.1% and 34.9% respectively. The FR mechanism of RGO-AZOB/SMB/PLA nanocomposites is based primarily on the glassy charring effect of the B–OH groups in AZOB and the inherent lamellar blocking effect of RGO. Image 1 [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A hierarchical MoS 2 @TiO 2 structure is firstly designed and synthesized. • The combination properties of BD with 2 wt% MoS 2 @TiO 2 loading is greatly enhanced. • The mechanism of MoS 2 @TiO 2 in enhancing combination properties of BD is proposed. Abstract Bismaleimide/diallyl bisphenol A (BD), a kind of allyl-modified bismaleimide (BMI) system, which is widely used in the fields of aviation, aerospace, machinery, and electronics. However, the further applications of BD are severely restricted by its high crosslink density, brittleness, and undesirable flammability. In order to overcome these drawbacks, a hierarchical MoS 2 @TiO 2 structure is designed and synthesized to improve the mechanical and fire safety of BD, which are well matched with the high curing temperature and application temperature of BD. Specifically, with a relatively low loading of 2 wt% MoS 2 @TiO 2 , then the peak heat release rate (pHRR) and total heat release (THR) of BD composites are 314.25 kW/m2 and 53.58 MJ/m2, respectively, which are decreased by 32.5% and 15.0% in comparison to those of the pristine BD. Meanwhile, the TSR and yields of poisonous gases, especially CO and nitric oxide of BD/MoS 2 @TiO 2 2.0 are greatly decreased which indicates that the fire safety is effectively enhanced. The impact strength of BD/MoS 2 @TiO 2 2.0 sample is increased to 12.44 kJ/m2, which corresponding to a 96.8% compared with that of pure BD, and its storage modulus is 44462 MPa, a little higher than that of pure BD. Furthermore, Tg of BD/MoS 2 @TiO 2 2.0 is increased to 326 °C with a lower cross-linking density while that of BD is 316 °C. Conclusively, this investigation demonstrates that the MoS 2 @TiO 2 is a significant nano-additive for developing high-performance BD resins with excellent fire safety and mechanical properties, which provides a novel strategy for designing advanced BD composite material. [ABSTRACT FROM AUTHOR]

[Display omitted] • A multifunctional additive (MCMH) is carefully designed. • The microencapsulation technology improves the compatibility between MCMH and XLEVA. • The OIT value of XLEVA/MCMH was basically unchanged after extracted for 5 days. • The retention of EB of XLEVA/MCMH could reach 71.8% after aging at 165 °C for 14 days. • The PHRR and Ds max of XLEVA/MCMH are reduced by 89.4% and 53.6%, respectively. A multifunctional additive is carefully designed for crosslinked ethylene–vinyl acetate copolymer (XLEVA) composites to improve their mechanical properties, aging resistance and fire safety. In this study, first, a layer of silica was microencapsulated on magnesium hydroxide to give a large amount of hydroxyl group on the magnesium hydroxide surface; second, the primary antioxidant 3-(3, 5-di- tert -butyl-4 hydroxyphenyl) propionicacid was grafted on SiMH surface to prepare antioxidant microencapsulated flame retardants (MCMH). Compared with the pure XLEVA, the peak heat release rate and the maximum smoke density of flame retardant XLEVA/MCMH are decreased by 89.46% and 53.6%, respectively. Moreover, these oxidation induction time values of XLEVA/MH/AO and XLEVA/SiMH/AO decreased sharply after extracted for 1d. However, the OIT value of XLEVA/MCMH was basically unchanged after extracted for 5d. After aging at 165 °C for 14 days and γ-ray irradiation dose of 500 kGy, the retention of elongation at break could reach 71.8% and 86.6%, showing excellent aging resistance. These results show that MCMH has a good synergistic effect for enhancing the flame retardant, mechanical property as well as aging resistance of XLEVA composites. The "Killing three birds with one stone" strategy provides an excellent solution for obtaining high-performance XLEVA cable materials. [ABSTRACT FROM AUTHOR]

• Two different flame retardants named as DOPO-GPTMS and DOPO-APTES were synthesized. • Flame retardant compounds were applied to PA66 fabric surfaces via sol-gel method. • The as prepared coatings could able to stop the melt-dripping of PA66. • PA66 treated with 20 wt% DOPO-APTES showed a maximum 36% reduction in pHRR. • Incorporation of Si-compounds enhanced charring ability of DOPO. Two different DOPO- Alkoxysilane based flame retardant compounds were synthesized and applied onto the polyamide 66 (PA66) fabric surfaces via sol-gel method to improve the thermal stability and flame retardant properties. The as prepared coatings exhibited a much higher char yield% compared to the pure PA66 and simultaneously suppressed the dripping tendency of PA66 in the vertical burning test. The fabric sample modified with 20 wt% of DOPO-APTES showed a significant reduction in the peak heat release rate (pHRR) by 36%, whereas the 20 wt% of DOPO-GPTMS treated fabric sample could manage a 20% reduction in pHRR. The supremacy of DOPO-APTES treated fabrics were due to the co-presence of P, Si, and N elements; where a DOPO structure showed a quenching effect in a vapor phase, and Si-compounds accelerated the limited charring of DOPO in a condensed phase and stabilized the char residues in a higher temperature range. Moreover, the as treated PA66 fabrics show some sort of wash durability and among them, the fabric sample treated with 20 wt% of DOPO-APTES can withstand against fierce laundering where it maintains UL-94V-1 rating even after 10 washing cycles. [ABSTRACT FROM AUTHOR]

Due to the inherent flammability of polypropylene (PP), it is limited in the application of flame retardant materials. In this work, a novel char forming agent, hyperbranched phosphorus-containing polyurethane (HPPU), was synthesized and used as efficient char forming agent. When ammonium polyphosphate (APP) was combined with HPPU, APP/HPPU endow PP significantly improved flame retardancy than single APP. Although the total carbon monoxide production (TCOP) of some PP/APP/HPPU composites is higher than that of PP/APP composite, it is still lower than that of neat PP. LOI (limited oxygen index) and UL-94 tests reveal that PP composites with 25 wt% HPPU/APP with ratio of 4:1 are able to reach 27 vol% and V-0 rating, respectively. The addition of 25 wt% APP/HPPU with ratio of 2:1 into PP can result in decrease in peak heat release rate of about 72%, decrease in total heat release of about 38% and decrease in TCOP of about 93%. APP/HPPU promotes PP to form more stable, compact, and continuous char layer which effectively hinder heat and oxygen transfer and protect the inner matrix from decomposition. Thermogravimetric-infrared results reveal that the gas phase flame retardant mechanism of APP/HPPU is the dilution effect of ammonia from APP and the flame inhibition effect of phosphorus-containing species from HPPU. Image 1 • A novel hyperbranched phosphorus-containing polyurethane (HPPU) is firstly synthesized. • LOI and UL-94 tests revealed that the addition of 25 wt % HPPU/APP into neat PP was able to reach 27 % and V-0 rating. • APP/HPPU exhibit remarkable flame retardant and carbon monoxide (CO) suppression to PP composites. [ABSTRACT FROM AUTHOR]

Finding a facile strategy to fabricate robust coating on the skeletons is crucial to improve the performance of flexible polyurethane foam (FPUF). Nanosized bimetal-organic frameworks (MOFs-NH 2) and (3-Mercaptopropyl) trimethoxysilane (MTS) were used to modify FPUF in this work to enhance its oil absorbency and flame retardancy. MTS used as adhesive to provide strong interaction between MOFs-NH 2 and FPUF. FPUF@MOFs-NH 2 showed superhydrophobicity even after compressive stain-stress test for 1000 cycles. Meanwhile, FPUF@MOFs-NH 2 sponges not only had higher oil absorbency than previous FPUF-based adsorbents, but also superior reusability. After 400 cycles adsorption-squeezing test, FPUF@MOFs-NH 2 still kept high absorbency. Fire safety of the sponge was significantly improved after coating MTS and MOFs-NH 2 : fire spread and heat release rate were significantly suppressed. The possible oil absorbency and flame retardancy mechanisms were proposed based on the analysis results. This work broadens the application field of MOFs and paves a new direction to prepare functional FPUF composites with excellent performance. Image 1 [ABSTRACT FROM AUTHOR]

Flame retardant flexible polyurethane foam (FPUF) was prepared through a free-foaming method with aluminum diethylphosphinate (ADP) as additive. The influence of ADP on the morphology, thermal and flame retardant properties of the FPUF was investigated, and the flame retardant mechanism was further explored. TGA results indicated that the addition of ADP slightly affected the initial degradation temperature and the maximum degradation temperature. With the increase of the ADP loading, the char yield of the resultant FPUF gradually increased. When the ADP loading was 20%, the peak heat release rate and the total heat release of the resultant FPUF was reduced by 35% and 33%, respectively, compared to the unmodified FPUF. The addition of ADP improved the char formation of the FPUF, which could inhibit the transfer of oxygen and flammable gases between the flame and the underlying polymer and thus improve the fire retardancy. • Influence of ADP loading on the flame retardant property of FPUFs was studied. • The presence of ADP almost did not affect the thermal stability of FPUF. • Addition of ADP decreased the peak heat release rate and total heat release of FPUF. • ADP functioned as flame retardant in both gas phase and condensed phase. [ABSTRACT FROM AUTHOR]

Rising concerns about the toxic effects and environmental issues associated with various fireproof treatments on textiles have led to a demand for "green" materials. Chitosan (CS) is an amino polysaccharide green, recyclable, and non-toxic highly biocompatible biopolymer that consists of multiple hydroxyl groups and has a wide range of applications, including as a flame retardant additive. In this study, an eco-friendly bio-based formaldehyde-free flame retardant containing a higher level of phosphorus and nitrogen in phytic acid ammonia (PAA) was synthesized to amplify the most plentiful green chitosan (CS)-modified polyamide 66 (PA66) fabric surface through a simple pad-dry-cure technique for the improvement of durable flame retardancy with hydrophilicity. The findings revealed that each UV-grafted CS fabric could entirely stop the melt-dripping tendency during the vertical burning (UL-94) test and reached a V -1 rating. Meanwhile, limiting oxygen index (LOI) testing showed a rapid increase from 18.5 % to 24 % for the PA66 control and the PAA-treated (i.e., PA66-g-5CS-PAA) fabric samples, respectively. Moreover, compared to the PA66 control sample, a dramatic decrease in the peak heat release rate (PHRR), fire growth rate (FGR), and total heat release (THR) by approximately over 52 %, 0.63 %, and 19.7 %, respectively, was observed for the PA66-g-5CS-PAA fabric sample. Additionally, this arrangement of PAA catalyzed the charring of grafted CS and acted as a condensed phase flame retardant, resulting in a significant improvement in char yield% in both air and N 2 atmospheres for the PA66-g-5CS-PAA fabric sample in TGA. In addition, only the lower grafting ratio of CS with PAA-treated fabric sample (i.e., PA66-g-2CS-PAA) could encourage it to gain its lowest water contact angle of 00, as well as impersonating a positive effect in improving the flame retardant coating durability in washing and sustaining even after 10 home laundering cycles. This phenomenon suggests that an actual hydrophilic and durable flame retardant finishing procedure for polyamide 66 fabrics might be applied with the novel, plentiful, sustainable, and environmentally friendly bio-based green PAA ingredient. [ABSTRACT FROM AUTHOR]

• A vanillin-derived bisDOPO co-curing agent (DVD) was successfully synthesized from vanillin and DOPO. • The introduction of DVD improved the mechanical properties of epoxy thermosets. • Epoxy with an ultra-low P content of 0.42 wt% exhibited an LOI of 30.5% and reached a UL-94 V-0 rating. To prepare transparent and flame-retardant epoxy thermosets, a vanillin-derived bisDOPO co-curing agent (DVD) was synthesized from vanillin and DOPO. The influence of DVD on the curing kinetics of the epoxy systems was investigated by non-isothermal differential scanning calorimetry (DSC). The introduction of DVD increased the activation energy of the curing process. Compared with pure epoxy, the storage modulus at 30 °C and tensile strength of EP/DVD-5% increased by 35.7% and 145%, respectively. Additionally, the epoxy thermosets still maintained excellent transparency. The addition of DVD improved the flame-retardant performance of epoxy thermosets by promoting the formation of char and reducing the thermal decomposition rate. Most importantly, DVD showed high flame retardant efficiency for the resulting epoxy thermosets. Specifically, with the incorporation of 5 wt% DVD (only 0.42 wt% phosphorus loading), the resulting epoxy thermoset exhibited a limiting oxygen index (LOI) value of 30.5% and reached a UL-94 V-0 rating. The cone calorimetry results showed that the total heat release (THR), peak value of heat release rate (PHRR), and total smoke production (TSP) of EP/DVD-5% decreased by 32%, 42%, and 21%, respectively, compared with the unmodified EP. The modes of action of flame retardant analysis indicated that DVD exhibited high flame retardant efficiency by serving as a charring promotor in the condensed phase and acting as a radical scavenger in the gaseous phase. The above results demonstrate that DVD is a promising flame retardant agent to render epoxy thermosets simultaneously improved flame retardancy, mechanical strength and transparency. [ABSTRACT FROM AUTHOR]

In this work, a flowering-branch like CNTs/Bi 2 Se 3 hybrids was synthesized by a facile in-situ method. CNTs as carrier could provide low agglomeration of layered Bi 2 Se 3 . As-prepared nanomaterials were added into epoxy resin (EP) to enhance its fire safety. Compared with neat EP, there were more than 44% and 23% decrease in the value of peak heat release and total heat release with 2 wt% content of CNTs/Bi 2 Se 3 , respectively, confirmed the enhancement of flame retardancy of EP composites. Meanwhile, the release of smoke and CO were also suppressed during EP combustion. From results of thermogravimetric analysis-infrared spectrometry, the addition of CNTs/Bi 2 Se 3 obviously reduced the release of organic gaseous products, which contributed to the improved fire safety of EP matrix. Based on the analysis of gas and condensed phases, the possible enhancement mechanisms can be mainly concluded as the barrier effect of as-synthesized binary hybrids and enhanced char layers. Meanwhile, the addition of CNTs/Bi 2 Se 3 enhanced the mechanical performance of EP composites. This work broadens the application fields of Bi 2 Se 3 and enriches the membership of CNTs-based binary compounds, which were used as flame retardants. [ABSTRACT FROM AUTHOR]

• An ionic confinement engineering approach is proposed to facilitate dynamic ionic crosslinking. • The ionomers deliver low dielectric-k property, high stretchability and fast self-healing capability. • The EGaIn-infused stretchable device is designed for electronic device reconfiguration. Ionomers are gaining much attention in the fields of soft robots, flexible electronics, and artificial intelligence. However, intrinsic dynamics modulation of ionomer molecules to achieve desirable properties is highly required and challenging due to a lack of understanding of the interactions between polymerics and ionic species. In this study, a novel ionic confinement engineering approach was employed, in which the composition of a copolymer, namely, PTAE-Fe, was adjusted to facilitate dynamic ionic crosslinking, which enables high stretchability (>10000 % elongation). The proportion of ionic functional groups in PTAE-Fe significantly enhanced the self-healing efficiency up to 95 %. The ionic confinement strategy also promotes electron momentum locking, resulting in a low dielectric-k property (D k < 2.5), while a reduction in the heat release rate of 69.1 % makes the ionomer an excellent flame retardant material. In addition, a eutectic gallium-indium (EGaIn)-infused stretchable device and low D k flexible ink were designed according to the ionic confinement strategy. The as-fabricated ionomer is expected to benefit a wide range of energy and storage technologies. [ABSTRACT FROM AUTHOR]

[Display omitted] • Phthalocyanine-zirconium polyphosphazene functionalized BP was obtained by crosslinking reaction. • BP-ZrPZN effectively reduced the total smoke release decreased by an impressive 62.7 %. • BP-ZrPZN can comprehensively improve the fire safety and mechanical properties of EP. The existence of lone pair electrons on the surface of black phosphorus (BP) is a good electron acceptor, which has good structural stability when it forms new electron donor-electron acceptor pairs when combined with electron donators such as phthalocyanine. In order to bond functional groups available for reaction on the surface of BP, the lamellae group density was increased by functionalizing BP with benzoic acid diazonium salt, and then the carboxylated BP was covalently grafted with phthalocyanine zirconium, and finally the phthalocyanine-zirconium polyphosphazene functionalized BP (BP-ZrPZN) was obtained by crosslinking reaction. Subsequently, BP-ZrPZN was added into the EP matrix as nano filler to form the reinforced system. The results showed that the thermal stability and fire safety of EP composites containing 2 wt% BP-ZrPZN were significantly improved. The peak heat release rate and total heat release rate were reduced by 56.8 % and 54.1 %, respectively, and the limited oxygen index was up to 33 % and UL94 value was V-0. In addition, the presence of BP-ZrPZN greatly improved the ability of BP to inhibit toxic smoke. The total smoke yield of EP composites decreased by 62.7 %. The tensile strength and impact strength increased by 36.1 % and 50.6 % respectively. Therefore, the functional strategy of phthalocyanine in this work will provide a reasonable and feasible way to optimize the flame retardancy and smoke suppression effect of BP. [ABSTRACT FROM AUTHOR]

The essence of this work lies in the large-scale production of high-quality graphene sheets and simultaneous functionalization with new electrochemical route. A multifunctional flame retardant with phosphazene rings is well designed to simultaneously exfoliate and functionalize graphene. Due to the antioxidant function of flame retardant, the electrochemically-exfoliated graphene sheets exhibit high quality and low defect (C/O = 10.4). Furthermore, the obtained graphene is noncovalently modified to form flame retardant functionalized graphene sheets (FGNS). Subsequently, the FGNS is applied to improve fire safety and mechanical performance of thermoplastic polyurethane (TPU). Compared to pure sample, the peak heat release rate and total heat release of TPU composites with the addition of 4 wt% FGNS are significantly decreased by 46.3% and 20.2%, respectively. The elongation at break and tensile strength of TPU are enhanced by 11.6% and 59.9%, respectively, with the addition of 2.0 wt% FGNS. The significant enhancement in fire safety is due to conjunct effects of FGNS and the flame retardant. Lower defect of graphene provides more stable layer structure, thus FGNS plays a remarkable barrier action to confine the escape of degradation products. The coated flame retardant is conducive to form compact and robust char residue by reacting with degradation products. In addition, the flame retardant facilitates the load transfer to the robust graphene sheets with improved interface interaction. Through an electrochemical route, designing a multifunctional flame retardant to simultaneously exfoliate and modify graphene provides new possibility for the industrialized application of graphene. [ABSTRACT FROM AUTHOR]

As one of the most widely used polymers, the intrinsic brittleness and high flammability bring about a stringent requirement for the practical application of epoxy resins (EPs). It is difficult to toughen EP without compromising its mechanical and thermal properties for many conventional toughening agents. Here, a novel furan-derived bio-based polyphosphazene (PFMP) with a flexible backbone and rigid side groups was prepared by the nucleophilic substitution reaction between polydichlorophosphazene (PDCP) and furfuralcohol. The resultant PFMP was incorporated into EP to realize exceptional toughening, strengthening, and flame retardant function. By adding 15% of PFMP, the limit oxygen index value is from 25% (EP) to 33% (EP/PFMP-15) and reaches the UL-94 V-0 rating. According to the cone calorimeter results, EP/PFMP-15 exhibits exceedingly reduced peak heat release rate (pHRR) (50.2%) and total heat release (THR) (49.6%). The significantly increased fire performance index (FPI) and decreased fire growth rate index (FIGRA) of EP/PFMP-15 demonstrate an improvement in its flame retardancy. The catalytic carbonization effect (condensed phase) and radical quenching effect (gas phase) of PFMP account for the greatly improved flame retardancy. Moreover, the impact and tensile tests indicate that PFMP can ameliorate the mechanical performance of EP with a maximum increase of impact strength (111.8%) and elongation at break (35.2%) for EP/PFMP-5. With 15% PFMP added, the tensile strength of EP/PFMP-15 increases by 40.4%. This work demonstrates that PFMP is expected to overcome shortcomings (flammability, toughness, and strength) of EP and spread its applied fields. [Display omitted] • Bio-based polyphosphazene with furfuralcohol side groups (PFMP) was synthesized. • PFMP exhibits evident flame retardant and mechanical enhancement effect on epoxy resins (EP). • The peak heat release rate of EP/PFMP-15 was 50.2% lower than pure EP. • The impact strength of EP/PFMP-5 was 111.8% higher than pure EP. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new flame retardant DOPONH 2 -S was synthesized. • It solved the problems of epoxy resin (EP) including flammability and brittleness. • DOPONH 2 -S achieved high efficiency in reducing THR, P -HRR and EHC of EP. • DOPONH 2 -S increased the impact strength and thermal stability of EP. Epoxy resin (EP) has two shortcomings: flammability and brittleness. Previous studies have improved brittleness or flame retardancy but they will compromise the glass transition temperature (T g) and thermal stability. Herein, a novel DOPO based phosphorus-, nitrogen- and sulfur-co-contained macromolecular flame retardant (DOPONH 2 -S) was synthesized and incorporated into EP to improve its flame retardancy and toughness with not damaging T g and thermal stability. After curing, both T g and the tensile strength of EP-2 improved at the addition of DOPONH 2 -S is 6.75 wt%. Simultaneously, the thermogravimetric analysis (TGA) results showed DOPONH 2 -S is helpful increasing the thermal stability of EP composites and protecting the polymer from further decomposition. In the fire safety test, EP-2 achieved V-0 rating in the vertical burning test and obtained a limiting oxygen index value of 30.5%. In comparison with pure EP, the peak heat release rate, total heat release and effective heat of combustion of EP-4 incorporated with 10.0 wt% DOPONH 2 -S were reduced by 59.1%, 58.5% and 46.3%, respectively. A two-phase mechanism was discussed to explain the combination effect in DOPONH 2 -S. In condensed-phase, rich char residue prevents the exchange of mass and heat during combustion. It also obstructs the release of combustible gases into the combustion zone. In gas-phase, the produced phosphorus- and sulfur-containing free radicals can capture active free radicals (H· and OH·), thus ending the chain reaction of combustion. Moreover, the addition of DOPONH 2 -S apparently improved the impact strength (62.5%). This work provided ideas for the development of multifunctional EP. [ABSTRACT FROM AUTHOR]

The dispersion problems of black phosphorus (BP) in polymer-based composites can be solved by designing isolation structure. An isolating structural material with functionalized BP nanosheets and polystyrene (PS) microspheres was prepared by molding method. Firstly, the sulfonated BP nanosheets with negative charge were obtained by electrochemical diazo modification (electrochemical diazo modification of BP is first report, and achieved good synchronous stripping and modification effect). The sulfonated BP and the PS microspheres with positive charge were self-assembled to form composite microspheres through strong electrostatic interaction. The prepared composite microspheres were further hot pressed near the glass transition temperature to selectively distribute the BP nanosheets at the interface of the fused PS microspheres. Therefore, the PS-BP isolation structure with uniform dispersion and reasonable distribution was obtained in the PS matrix. Thanks to this unique structure, the maximum heat release rate and smoke production rate reduction of the isolation structure can reach 50.1% and 43.3%, which at an excellent level in the same kind of two-dimensional material based composites. The tensile strength is maximally increased by 71.7% when the filling amount is 1.0 wt%. This simple method provides a new strategy for modifying BP and is expected to be applied to the preparation of high performance polymer-based composites. [Display omitted] • An isolation structure with black phosphorus and polystyrene microspheres is achieved. • The electrochemical diazo modification of black phosphorus is the first report. • The heat release rate and smoke production rate of the isolation structure is significantly reduced. [ABSTRACT FROM AUTHOR]

The dispersion problems of black phosphorus (BP) in polymer-based composites can be solved by designing isolation structure. An isolating structural material with functionalized BP nanosheets and polystyrene (PS) microspheres was prepared by molding method. Firstly, the sulfonated BP nanosheets with negative charge were obtained by electrochemical diazo modification (electrochemical diazo modification of BP is first report, and achieved good synchronous stripping and modification effect). The sulfonated BP and the PS microspheres with positive charge were self-assembled to form composite microspheres through strong electrostatic interaction. The prepared composite microspheres were further hot pressed near the glass transition temperature to selectively distribute the BP nanosheets at the interface of the fused PS microspheres. Therefore, the PS-BP isolation structure with uniform dispersion and reasonable distribution was obtained in the PS matrix. Thanks to this unique structure, the maximum heat release rate and smoke production rate reduction of the isolation structure can reach 50.1% and 43.3%, which at an excellent level in the same kind of two-dimensional material based composites. The tensile strength is maximally increased by 71.7% when the filling amount is 1.0 wt%. This simple method provides a new strategy for modifying BP and is expected to be applied to the preparation of high performance polymer-based composites. [Display omitted] • An isolation structure with black phosphorus and polystyrene microspheres is achieved. • The electrochemical diazo modification of black phosphorus is the first report. • The heat release rate and smoke production rate of the isolation structure is significantly reduced. [ABSTRACT FROM AUTHOR]