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Graphite anode materials and carbonate electrolyte have been the top choices for commercial lithium-ion batteries (LIBS) for a long time. However, the uneven deposition and stripping of lithium cause irreversible damage to the graphite structure, and the low flash point and high flammability of the carbonate electrolyte pose a significant fire safety risk. Here, we proposed a multifunctional electrolyte additive diphenylphosphoryl azide (DPPA), which can construct a solid electrolyte interphase (SEI) with high ionic conductivity lithium nitride (Li3N) to ensure efficient transport of Li+. This not only protects the artificial graphite (AG) electrode but also inhibits lithium dendrites to achieve excellent electrochemical performance. Meanwhile, the LIBS with DPPA offers satisfactory flame retardancy performance. The AG//Li half cells with DPPA-0.5M can still maintain a specific capacity of about 350 mAh/g after 200 cycles at 0.2 C. Its cycle performance and rate performance were better than commercial electrolyte (EC/DMC). After cycling, the microstructure surface of the AG electrode was complete and flat, and the surface of the lithium metal electrode had fewer lithium dendrites. Importantly, we found that the pouch cell with DPPA-0.5M had low peak heat release rate. When exposed to external conditions of continuous heating, DPPA significantly improved the fire safety of the LIBS. The research of DPPA in lithium electrolyte is a step towards the development of safe and efficient lithium batteries. [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]

Biomass-derived carbon has been recognised as a green, economic and promising flame retardant (FR) for polymer matrix. In this paper, it is considered that the two-dimensional (2D) structure of carbonised peanut shells (PS) can lead to a physical barrier effect on polymers. The carbonised sample was prepared by the three facile methods, and firstly adopted as flame retardants for epoxy resin. The results of thermal gravimetric analysis (TGA) and cone calorimeter tests indicate that the carbon combined with nano Cobalt provides the most outstanding thermal stability in the current study. With 3 wt.% addition of the FR, both peak heat release rate (pHRR) and peak smoke production rate (PSPR) decrease by 37.9% and 33.3%, correspondingly. The flame retardancy mechanisms of the FR are further explored by XPS and TG-FTIR. The effectiveness of carbonised PS can be mainly attributed to the physical barrier effect derived by PS's 2D structure and the catalysis effect from Cobalt, which contribute to form a dense char layer. [ABSTRACT FROM AUTHOR]

[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]

[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]

• 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 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]

[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 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]

• 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]

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]

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]

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]

[Display omitted] • The octopus sucker-inspired M@CN with hierarchical structure is successfully synthesized. • The Interface engineering between M@CN and TPU matrix is greatly improved. • TPU/M@CN demonstrates superior improvement of TS of 79.5% and EB of 113.5%. • The pHRR and smoke suppression of TPU/M@CN-3 are reduced by 54.1% and 40.4%, respectively. Developing high-performance polymer materials with excellent mechanical properties and fire safety in fires remains a thorny challenge. In this article, hierarchical structure MXene@carbon nanotubes (M@CN) are prepared through electrostatic interactions for enhancing the interfacial engineering of thermoplastic polyurethane (TPU). With biomimetic method, the TPU/M@CN-3 nanocomposites performed octopus sucker-inspired structure during the stretching behavior, making the tensile strength and elongation at break of TPU/M@CN-3 increase 79.5% and 113.5%, respectively. What's more, thanks to the 1D-2D hierarchical structure of M@CN, fire safety of these TPU nanocomposites were extremely reinforced. Compared with the pure TPU, the TPU/M@CN-3 of peak heat release rate (pHRR) and smoke density max (Ds max) reduced by 54.1% and 40.4%. The production rates of carbon monoxide (CO) and carbon dioxide (CO 2) were reduced by 62.7% and 33.0%, respectively. Therefore, this work provides a convenient way to prepare a high-performance TPU with highly mechanical properties and fire safety through enhacing the interfacial engineering. [ABSTRACT FROM AUTHOR]

[Display omitted] • Utilizing the flame retardancy advantages of polyphosphazene and melamine, PPM was firstly designed and synthesized. • PPM has a positive effect on enhancing the fire safety and mechanical properties of BMI. • PPM is an integrated intumescent flame retardant and the cooperation effect of polyphosphazene and melamine in PPM is revealed. In view of the problems of poor toughness and high fire risk of bismaleimide (BMI), a novel maleimide-functionalized triazine-rich polyphosphazene microsphere (PPM) was designed and prepared in this work by combining the flame retardant advantages of polyphosphazene and melamine. The functionalization of organic maleimide in PPM can improve the interfacial compatibility between PPM and BMI. With addition of 2.0 wt% PPM, the peak value of heat release rate (PHRR) and total smoke production (TSP) of BMI/PPM-2.0 decrease by 52.8 % and 30.8 %, respectively, while its impact strength increases by 97.5 %, which means that the fire safety and toughness of BMI/PPM are much better. The study on flame retardant mechanism of PPM reveals that PPM has obvious condensed-phase intumescent flame-retardant effect, which may be due to the similar composition of PPM and intumescent flame retardant. In addition, PPM has the phosphorus-oxygen radical flame-retardant effect in gas phase and also has the toughening effect of inorganic rigid particles on BMI performance. [ABSTRACT FROM AUTHOR]

• Cardanol-derived anhydride cross-linked epoxy thermosets achieved UL-94 V-0 grade. • A remarkable reduction in the PHRR value of 47.7% was observed. • Cardanol-derived anhydride imparted excellent toughness to the cured epoxy. • Cardanol-derived anhydride cross-linked epoxy showed high shape recovery efficiency of more than 96% With the increasing awareness of environmental protection, the development of high-performance bio-based epoxy resins has attracted more and more attention to reduce the dependence on the petroleum-based 4,4′-diaminodiphenylmethane (DDM). In this work, we synthesized two kinds of cardanol-based curing agents (Car-DCP-MAH and Car-DPC-MAH) as alternatives for petroleum-based DDM. The chemical structures of Car-DCP-MAH and Car-DPC-MAH were confirmed by 1H and 31P NMR. Compared with the traditional DGEBA/DDM thermoset, the cured DGEBA/Car-DCP-MAH and DGEBA/Car-DPC-MAH thermosets both displayed good intrinsic fire resistance in terms of higher LOI values (29% and 28%, respectively, versus 24.5%) and V-0 rating in the UL-94 test. Furthermore, the results of the cone calorimeter test showed a significant reduction in the peak heat release rate (PHRR) values of the cured DGEBA/Car-DCP-MAH and DGEBA/Car-DPC-MAH which were 42.3% and 47.7%. The flame retardancy of these two systems was mainly due to the great carbonization ability and the formation of the intact and compact char layer. Owning to the flexible long alkyl chain in the crosslinking network, the toughness of the cured DGEBA/Car-DCP-MAH and DGEBA/Car-DPC-MAH products was greatly improved with the higher elongation at break and impact strength. Additionally, the cured DGEBA/Car-DCP-MAH and DGEBA/Car-DPC-MAH thermosets both showed preferable shape memory properties with a high shape recovery efficiency of 98.6% and 96.3%. This study provides a novel strategy to achieve bio-based epoxy thermosets with intrinsic anti-flammability, toughness and shape memory effect. [ABSTRACT FROM AUTHOR]

Devoting to coping with safety risk spreading with polymers, this work achieves dramatic synergistic improvements in composite toughness, photothermal healing, and fire safety through a novel targeted modification strategy for black phosphorus (BP). In detail, we herein use the emerging 2D BP as a template for in-situ growth by covalent triazine framework (HBP-CTF). Incorporating gradient increased HBP-CTF (1, 2, 4 wt%) into polystyrene (PS), the elongation at break increased by 61.59%, 74.60% and 62.82% for composites, respectively. This is attributed to the synergistic effects of two components of HBP-CTF as stress conduction unit and interface and dispersion improver, respectively. Furthermore, PS/HBP-CTF composites achieve photothermal healing over 96% in strength and elongation at break induced by outstanding photothermal properties (linearly quantifiable, R2 > 0.997). Noted, PS/HBP-CTF 2.0 and PS/HBP-CTF 4.0 achieve record reductions of 61.77% and 69.85% in peak heat release rate, accompanied by dramatically reduced total heat release. Taking the pyrolysis of HBP-CTF as an index, this work proposes the idea of using P 4 as the key product to monitor and distribute gas phase effects for BP-based flame retardants. The hybridization of CTF to HBP promotes the slow and continuous release of P 4 in the gas phase, revealing the structure and composition of char that cross-linking P and N. This work provides strategies for synergistically overcoming composite brittleness, crack failure, and high flammability, paving the way for practical applications. [ABSTRACT FROM AUTHOR]

Taking into consideration the frigid and thunderstorms, the flame retardancy and de-icing performance are simultaneously desiderated for some open-air key equipment, such as air fuselage and wind turbine blades. Here, inspired by the anti-reflection phenomenon of moth eyes and cicada wings, a multi-functionalized and biomimetic MXene@SnO 2 hierarchical nanostructure is prepared to effectively impart flame retardancy and solar de-icing performance to thermoplastic polyurethane (TPU) resin used widely as the finishing coat of protective materials of open-air equipment. Based on the catalytic effect and barrier function, the addition of hierarchical MXene@SnO 2 nanostructures also effectively decreases the release of heat and toxic smoke from PU resin, as confirmed by reductions of 50.5% and 33.1% in the peak heat release rate and smoke production rate, respectively. Due to the appropriate refractive index, the light reflection phenomenon is effectively suppressed, thus promoting solar absorption (∼90% at 0.4 mm film) and photo-thermal conversion (∼74.2 °C with simulated solar illumination of 1.0 kW/m2) in TPU-MXene@SnO 2 nanocomposites. Within the environment of −20 °C, the surface temperature of TPU-MXene@SnO 2 nanocomposites is still up to 32.7 °C and the surface ice pellet begins to melt at ∼40s, much earlier than 600s of pure TPU resin. In addition, the practical application of functionalized TPU nanocomposites is further improved by the higher mechanical properties, attributed to the strong interfacial interaction. Inspired by moth eyes and cicada wings, flame retardancy and solar de-icing performance are first integrated into polymer materials, thus effectively promoting their application in some extreme environments. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Environmentally friendly new flame retardant f-HAPNW was successfully prepared. • f-HAPNW achieved high filler efficiency in reducing THR and TSP of UPR nanocomposites. • UPR/f-HAPNW 0.5 achieved an 61.2 % increase in impact strength. • Novel flame retardancy and mechanical reinforcement mechanism about f-HAPNW. Non-toxic, low-smoke, high-efficiency and environmentally friendly flame retardants have become a hot issue at present. Here, polyphosphazene crosslinked by hexachlorocyclotriphosphazene (HCCP), 3-aminopropyltriethoxysilane (APTES), and dopamine (DA) was used to modify hydroxyapatite nanowires (HAPNW), obtaining a new environmentally friendly nanohybrids (f-HAPNW). Immediately afterwards, f-HAPNW was incorporated in unsaturated polyester (UPR) matrix in the presence of a nanowire structure with a high aspect ratio, accompanied by excellent interfacial compatibility. The incorporation of a small amount of f-HAPNW achieved an overall improvement in the fire safety and mechanical properties of UPR nanocomposites, including 23% decrease in total heat release rate (THR), 25.7% and 29.5% reduction in total smoke production (TSP) and the peak of CO production rate (PCOP) when the content was 2.0 wt%; 80.1% and 11.9% simultaneous increase in tensile strength and fracture elongation, and 61.2% increase in impact strength when the content was 0.5 wt%. Compared with similar previous research, the introduction of bio-based materials and environmentally friendly flame retardants in the design achieved significant flame-retardant filler efficiency, while considering the issues of reducing smoke release and environmental pollution. In general, this work innovatively prepared an environmentally-friendly hierarchical f-HAPNW structure, and achieved a comprehensive improvement in the performance of UPR nanocomposites, providing a reference idea for the design of high-performance UPR nanocomposites. [ABSTRACT FROM AUTHOR]

A novel carbon fiber/MXene coalition (CF-Ar-MXene) is synthesized via a bidirectional aryl diazonium chemistry method using p-phenylenediamine as a chemical bridge, which effectively combines the two materials with different dimensions and makes full use of the advantages of both. CF-Ar-MXene coalition materials achieve high surface roughness and rich oxygen-containing active groups due to the presence of MXene on the surface of CF, which leads to the favorable interfacial interaction and compatibility between CF-Ar-MXene and epoxy resin (EP) matrix. As expected, after the incorporation of CF-Ar-MXene coalition into EP matrix, the flame retardancy and mechanical properties of EP composites are significantly improved. For example, with the addition of 3 wt% CF-Ar-MXene coalition, the peak heat release rate (PHRR), total heat release (THR) and total smoke production (TSP) of EP composites decrease by 42.6%, 48.2% and 32.1%, respectively. Meanwhile, the TG-IR results indicate that the amount of combustible volatile products and toxic gases also significantly decrease. Notably, with 2 wt% loading of CF-Ar-MXene coalition in EP composites, the tensile strength and elongation at break increase by 49.9% and 40.5%, respectively. Therefore, the efficient cooperation between CF and MXene in CF-Ar-MXene coalition and excellent interface compatibility with EP matrix are the main reasons for the excellent flame retardancy and mechanical properties of EP/CF-Ar-MXene composites. [Display omitted] • CF-Ar-MXene coalitions were prepared by a bidirectional aryl diazonium chemistry method for the first time. • The method used in this experiment is efficient and eco-friendly compared with the traditional modification method for CF. • CF-Ar-MXene coalitions achieved high filler efficiency in reducing the fire hazards and smoke production of EP. • Mechanical properties of EP/CF-Ar-MXene composites were efficiency enhanced. [ABSTRACT FROM AUTHOR]

To tailor the enhancement strategies for polymers according to structure, inspired by the concept of "Cannikin's Law", this work proposes and exemplifies a novel strategy for reinforcing the carbonate linkages to simultaneously improve the thermal and fire safety of polycarbonate (PC). Herein, we introduce MIL-53(Al) to functionalize black phosphorus (BP@MIL-53) via a simple method of hydrothermal. As expected, the incorporation of BP@MIL-53 (1.0 wt%) in PC, resulted in an increase in T 1% of 32 °C and 41 °C under nitrogen and air respectively, along with the reduction of 49.4% and 19.3% for peak heat release rate and total heat release. Moreover, PC/BP@MIL-53-1.0 passed the V-0 rating of UL-94 with a high limiting oxygen index (LOI) value of 30.5%, which achieved the dual purpose of simultaneously enhancing the thermal stability and flame retardancy of PC. In addition, the addition of flame retardants had no effect on the tensile strength of the PC. These results demonstrate the high flame retardant efficiency of BP@MIL-53 at ultra-low addition levels. Moreover, these results also illustrate the forward-looking nature of the strategy of tailoring flame retardants to the properties of the substrate. This work combines the advantages of black phosphorus (BP) and Mental organic frameworks (MOFs) materials. The carbonate linkages reinforcement approach provides a viable, new, and scalable idea for polyester compounds' thermal and fire safety properties. [Display omitted] • Novel flame retardants designed to suit the structure of polycarbonate. • Significantly improved thermal stability of polycarbonate. • Highly efficient flame retardant with ultra-low addition levels. • Ester-based reinforcement and char formation strategies inspired by the "Cannikin's Law". [ABSTRACT FROM AUTHOR]

The weak anti-oxidation and smoke-suppression abilities limit the use of black phosphorus (BP) in the preparation of high-performance flame-retardant epoxy resin (EP) composites. Here, aromatic diazonium chemistry was used to graft phenylboronic acid on the surface of few-layer BP nanosheets (BPNSs) to obtain passivated BP-based nanomaterials (BP-DPBA). Then, a novel multifunctional nano flame retardant BP-DPBA@Co-BO was obtained by anchoring amorphous cobalt-based borate (Co-BO) on the surface of BP-DPBA through a low-temperature reduction reaction. Subsequently, BP-DPBA@Co-BO was incorporated into EP matrix in the form of nanofillers and formed a mechanically enhanced system. As expected, EP nanocomposites containing 2 wt% BP-DPBA@Co-BO achieves greatly improvements in thermal stability and fire safety, with 93% increase in char yield (CY) during pyrolysis, 48.4% and 41.7% decrease in peak heat release rate (PHRR) and total heat release (THR) during combustion respectively, a limiting oxygen index (LOI) value up to 32.5% and a UL94 rating of V0. In addition, the presence of Co-BO greatly improves the ability of BP to suppress toxic smoke. Specifically, EP/BP-DPBA@Co-BO 2.0 achieves a 25.4% reduction in total smoke production (TSP) during combustion. In particular, the maximum 36.2% and 73.2% increases are achieved in storage modulus and impact strength, respectively, confirming that BP-DPBA@Co-BO can effectively enhance the mechanical properties of EP. Therefore, this work provides a feasible solution for loading high-valence metal compounds on the surface of BPNSs, and prepared high-performance EP nanocomposites with enhanced fire safety and mechanical properties. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel phosphine oxide-containing hyperbranched polyol was synthesized. • RPUF containing POCHP and EG exhibit excellent fire safety and physical properties. • The production of CO and NO x during combustion of RPUF are significantly decreased by combination of POCHP and EG. In this work, a novel phosphine oxide-containing hyperbranched polyol (POCHP) was synthesized. Then POCHP and/or expandable graphite (EG) were incorporated into rigid polyurethane foam (RPUF). EG increases foam density and deteriorates compressive strength and thermal conductivity, but POCHP has opposite effects. A 12.8% improvement of compressive strength and slightly decreased density and thermal conductivity are achieved by ERPUF50 containing POCHP and EG. And it reaches a limited oxygen index of 30.0% and UL-94 V-0 rating with immediate self-extinguishing behavior after removing flame. The peak heat release rate, total heat release and total smoke production of ERPUF50 are reduced by 71.1%, 52.2% and 71.1% respectively via bi-phase flame retardant mechanisms. Interesting phenomena were observed that POCHP promotes the intumescence of EG after combustion. The results of combustion gas analysis reveal that single POCHP or EG reduces the production of CO but increases the generation of NO x. ERPUF50 exhibits a 52% decrement of CO and an unexpected 40% diminishment of NO x. ERPUF50 with excellent comprehensive properties can not only be used as fire safe thermal insulation material with high physical performances, but also significantly reduce the release of contaminative smoke, CO and NO x in fires and waste RPUF disposal by combustion. [ABSTRACT FROM AUTHOR]

As known, the poor toughness and low fire safety of bismaleimide resin (BMI) has become a problem which restricts its further application in advanced high-performance field. Therefore, a novel allyl-functionalized linear polyphosphazene (PMAP) was designed and synthesized. With inclusion of 3wt% PMAP, the peak heat release rate (PHRR) and total smoke production (TSP) of BMI/PMAP-3 are reduced by 51.3% and 17.8%, respectively. And the residual char of BMI/PMAP increases significantly as well. Furthermore, the flame-retardant mechanism of BMI/PMAP is proposed. In condensed phase, PMAP can participate in the formation of residual char of BMI/PMAP and the char layer is with an excellent physical barrier effect by the existence of phosphorus oxygen and phosphorus nitrogen cross-linking substances. In gas phase, phosphorous oxygen free radical is also generated from PMAP, which can capture gas-phase chain free radicals and inhibit gas-phase combustion. Moreover, the impact strength of BMI/PMAP-3 increases by 85.3%, which indicates that the toughness of BMI/PMAP is effectively enhanced. The toughening mechanism of PMAP on BMI can be assigned to elastomer toughening. Therefore, with modification of PMAP, BMI/PMAP is indeed of better comprehensive performance, which is in line with expectation and provides inspiration for the simultaneous flame-retardant and toughening modification of BMI. [Display omitted] • Innovation: bifunctional allyl functionalized linear polyphosphazene was firstly synthesized. • High-efficiency: the PHRR and impact strength of BMI/PMAP-3 is reduced by 51.3% and increased by 85.3%. • Mechanism: the flame retardant and toughening mechanism is proposed. [ABSTRACT FROM AUTHOR]

• Hydrophobic hierarchical OH-BN@CuCoOx was innovatively prepared by the MOF-derived strategy. • OH-BN@CuCoOx achieved high filler efficiency in reducing THR and TSP of BMI. • BMI/OH-BN@CuCoOx 0.5 achieved an 80 % increase in impact strength. • BMI/OH-BN@CuCoOx 0.5 achieved a 49 °C increase in Tg. In this work, the MOF-derived strategy was used to generate copper-cobalt metal oxide (CuCoOx) in situ on the surface of hydroxylated boron nitride (HO-BN), and a new type of nano-hybrid (HO-BN@CuCoOx) was obtained. Then, HO-BN@CuCoOx was dispersed in the bismaleimide resin (BMI) matrix in the form of a layered structure, forming a strong interface interaction. The results of the cone calorimeter test exhibited that the fire hazard and toxic smoke release of BMI nanocomposites containing 2 wt% HO-BN@CuCoOx were effectively suppressed, such as a 37.2% reduction in total heat release rate (THR), a 38.5% reduction at peak heat release rate (PHRR), 24.3% decrease in total smoke production (TSP) and 62.2% decrease in peaks of carbon monoxide (CO) production rate. Compared with previous studies, higher filling efficiency was achieved. In addition, BMI/HO-BN@CuCoOx 0.5 achieved an 80% increase in impact strength, revealing excellent toughness. In particular, the glass transition temperature (Tg) of BMI/HO-BN@CuCoOx 0.5 reached 330 °C, an increase of 49 °C compared to the pure sample, which increased the potential for application in extreme environments. Therefore, the developed new BMI/HO-BN@CuCoOx nanocomposites expanded the application potential of BMI in the high-end field. [ABSTRACT FROM AUTHOR]

Conductive polymer composites have been caught increasing attentions in electromagnetic interference (EMI) shielding field. Due to the flammability of polymer and long-term high power working status, fire incidents on environment and human health must be taken into consideration during the preparation of the polymer materials. Thus, developing an EM waves-clean material with exceptional fire safety and smoke suppression capacity is the vital issue. In this article, a facile and eco-friendly approach to fabricate flame retardant polyurethane (PU) sponge was carried out by layer-by-layer (LBL) self-assembly with octaammonium-polyhedral oligomeric silsesquioxane (OAPOSS) and titanium carbide (Ti 3 C 2 T x) nanosheets. With the help of silicane and the barrier effect from Ti 3 C 2 T x , the peak heat release rate (pHRR) and total heat release (THR) decreased by 50%. Thanks to the exceeding catalytic capacity of Ti 3 C 2 T x nanoflakes, the production of harmful smokes or gases such as carbon oxide (CO) and carbon dioxide (CO 2) were sharply reduced with 71% and 27%, respectively. Furthermore, the flame retardant PU sponge obtained electromagnetic interference (EMI) shielding capacity after dip-coating procedure in MXene dispersion owing to the excellent electrical conductivity of Ti 3 C 2 T x nanosheets. The EMI shielding effectiveness (EMI SE) accomplished 32.57 dB and still remained 27.63 dB after 300 times compression. Therefore, this work could provide a promising way to accomplish flame retardant PU sponge with superior smoke suppression capacity, which could be used in cleaner production of modern electronics and EMI shielding materials. [Display omitted] • The facile cleaner approach to obtain multifunctional polyurethane (PU) sponge. • OAPOSS@MXene nanocoating was constructed on PU sponge via a clean layer-by-layer method. • The peak heat release rate and CO production was decreased by >50% and 71%, respectively. • Electromagnetic interference shielding capability remained >85% after 300 times compression. • Toxic fire effluents release-cleaner, electromagnetic waves-cleaner production of PU sponge were achieved. [ABSTRACT FROM AUTHOR]

[Display omitted] • 0D-2D hierarchical nanostructure was prepared via ZHS in-situ growing on Ti 3 C 2 T x. • EP-ZHS@M composites show up superior improvement of thermal conductivity of 328%. • EP-2.0 ZHS@M performed low pHRR of 54.91% and outstanding smoke suppression. • ZHS@M cut off the thermal disaster chain for safer package materials. Epoxy resin (EP) is widely used in the package of modern electronic products for thermal management, but the extremely flammability and toxicity release have restricted its further application. In this article, zinc hydroxystannate (ZHS) nanocubes were in-situ fabricated on the surface of titanium carbide (Ti 3 C 2 T x) MXene nanosheets (ZHS@M) for improving the thermal management capacity of EP. Due to the phonon thermal conductance from ZHS and electron-hole thermal conductance of Ti 3 C 2 T x , the thermal conductivity was improved by 328% compared with the neat EP, which was benefit to dissipate heat for reducing the possibility of thermal disaster chain happening. Furthermore, owing to the 0D-2D hierarchical structure of ZHS@M, the fire safety and smoke suppression of these EP composites were highly strengthened. The peak heat release rate (pHRR) and total heat release (THR) decreased by 54.91% and 58.74%, respectively. Moreover, hazardous gases of EP during the combustion were also efficiently reduced, and the generation of carbon oxide (CO) and carbon dioxide (CO 2) were decreased by 44.44% and 39.46% when the additive of ZHS@M was only 2 wt%. As a result, ternary catalytic effect and labyrinth structure improved the safety of EP in the thermal runaway incidents. Besides, EP-2.0 ZHS@M exhibited excellent tensile robustness (64.71 MPa) and modulus (2.39 GPa), which regarded as a reliable supporting material for electronics in thermal management field. Hence, this hierarchical EP-ZHS@M composites provided the help of cleaning the thermal accumulation and increasing fire safety while facing thermal runaway, which was significant to destroy the formation of thermal disaster chain and further applications of the modern electrons and devices. [ABSTRACT FROM AUTHOR]

• Hierarchical Ti 3 C 2 T X @PHbP-PHC architecture was innovatively synthesized. • Ti 3 C 2 T X @PHbP-PHC exhibited significant decrease in PHRR, THR and TSP. • BMI/Ti 3 C 2 T X @PHbP-PHC 0.5 achieved a significant increase in impact strength. • The synergistic mechanical reinforcement and flame-retardant mechanism among Ti 3 C 2 T X , PHbP and PHC was innovatively revealed. The effect of hindered amine light stabilizer on free radical quenching can be combined with the cross-linked polyphosphazene containing P N structure to improve the flame retardant efficiency of titanium carbide (Ti 3 C 2 T X) in both gas phase and condensed phase. Here, a hindered amine and polyphosphazene modified Ti 3 C 2 T X (Ti 3 C 2 T X @PHbP-PHC) was obtained. With the loading of Ti 3 C 2 T X @PHbP-PHC in the bismaleimide resin (BMI) increased to 2 wt%, an 43% reduction was achieved in the peak heat release rate (PHRR), and a 47% reduction in the total heat release rate (THR). Meanwhile, the total gaseous products and total smoke production (TSP) exhibited a similar decreasing trend. Furthermore, 0.5 wt% BMI system exhibited the highest storage modulus (2629 MPa) and impact strength (13.7 MPa), which were 21% and 76% higher than pure BMI, respectively. Therefore, the developed functionalized Ti 3 C 2 T X can be effectively used in BMI matrix, thereby providing reliable source material for the design of high-performance BMI resins that meet various application scenarios. [ABSTRACT FROM AUTHOR]

[Display omitted] • The linear polyphosphazene and MoSe 2 hybrid (LPP-MoSe 2) was constructed. • EP/LPP-MoSe 2 exhibits low PHRR, THR, EHC, TSP, CO yield and CO 2 yield. • LPP-MoSe 2 shows synergistic flame retardant effect in gas-phase and condensed-phase. • LPP-MoSe 2 displays significant toughening and strengthening effect on EP. Epoxy resins (EP) are deemed as one kind of most commonly used thermosets, but immanently suffer from inflammability and brittleness. Herein, we report a newly designed hierarchical molybdenum diselenide (MoSe 2) nanotubes assembled from several-layered nanosheets, and then merged with linear polyphosphazene (LPP) for constructing LPP-MoSe 2 hybrids. LPP-MoSe 2 possesses great advantages in improving the properties of EP for their typical nanotube structure and the combination effect of transition metal, phosphorous and nitrogenous compounds. The developed EP/LPP-MoSe 2 composites present obvious reduction in flammability, obtaining a high LOI value of 29% and reaching V-0 rating in UL-94 test. They also exhibit obvious reduction in the heat hazards of EP, such as peak heat release rate (39.0%) and total heat release (24.8%), as well as the toxicity hazards including total smoke production (31.3%) and the yields of CO and CO 2. Gas-phase and condensed-phase mechanism are elucidated to explain the contribution of LPP-MoSe 2 to the fire retardation of EP. Moreover, the addition of LPP-MoSe 2 can also obviously enhance the mechanical properties of EP. The impact strength of EP is only 9 kJ/m2, while EP/LPP-MoSe 2 3.0 can reach up to 14.2 kJ/m2. Based on tensile test, the well-dispersed LPP-MoSe 2 also leads to significant elevation in tensile strength (74.6%) and elongation at break (100%) of EP. Our data demonstrate that LPP-MoSe 2 shows impressive performance in developing high-performance EP composites, thereby broadening the practical application of EP. [ABSTRACT FROM AUTHOR]

[Display omitted] • Phosphorylated cardanol-based oligomers were synthesized for flame-retardant and toughened epoxy. • The elongation at break of the treated epoxy was 133.3% higher than that of neat epoxy. • The peak heat release rate of the treated epoxy was 53.8% lower than pure epoxy. • The residual yield of EP/CF-PO(OPh) 2 –10 under nitrogen was 52.7% higher than that of pure epoxy. • Cardanol-based oligomer with higher phosphorus oxidation state showed better flame-retardant efficiency. Presently, flammability and brittleness are two major problems for EP which has restricted its development and application in industrial. Under the global advocacy of green and sustainable development, developing bio-based flame-retardant and toughening agents which can endow epoxy resins with high fire resistance and satisfactory mechanical properties is of significant demand for its industrial applications. Herein, three kinds of phosphorylated cardanol-formaldehyde oligomers (CF-PO(OPh) 2 , CF-POPh 2 , and CF-PPh 2) were synthesized and introduced into epoxy thermosets. The incorporation of CF-PO(OPh) 2 , CF-POPh 2 , and CF-PPh 2 can remarkably improve the mechanical performance of EP composites, especially the tensile strength and elongation at break. With 10 wt% of CF-PO(OPh) 2 , CF-POPh 2 , and CF-PPh 2 , the tensile strength of epoxy thermosets reached 67.1, 74.5, and 70.3 MPa, respectively; the elongation at break of epoxy thermosets was raised by 133.3%, 162.5%, and 150.0%, respectively, as compared to neat EP. EP composites containing CF-PO(OPh) 2 , CF-POPh 2 , and CF-PPh 2 also exhibited remarkably enhanced flame retardancy simultaneously. Besides, CF-PO(OPh) 2 exhibited the best flame-retardant efficiency by comparison with CF-POPh 2 and CF-PPh 2 , and the results manifested that epoxy composite with only 2.5 wt% CF-PO(OPh) 2 could pass the UL-94 V-0 rating as well as a high LOI value of 28%, and the LOI value of EP/CF-PO(OPh) 2 –10 reached up to 32%. Moreover, CF-PO(OPh) 2 also displayed an excellent catalytic charring effect and great suppression effect on heat and smoke release. The cone calorimeter test results showed that EP composite containing 10 wt% CF-PO(OPh) 2 exhibited the most significant PHRR reduction which was 53.8% lower than pure EP, and the char yield of EP/CF-PO(OPh) 2 –10 after the cone calorimeter test was 14.0% which was much higher than that of pure EP (5.7%). This work opens a new vision for the synthesis of bio-based flame-retardant and toughening agents with a special oligomeric structure combining rigidity with flexibility, and contributes to the production of high-performance epoxy thermosets. [ABSTRACT FROM AUTHOR]

Nowadays, highly flexible, ultrathin, and conductive polymer composites are exceptionally desirable for electromagnetic interference shielding (EMI) applications due to their unique mechanical strength and electrical and flame-resistant properties. While the traditional nanocomposites blending remains the mainstream method to fabricate polymer/inorganic composites, it results in poor electrical conductivity caused by the discontinuous connection of conductive network as well as the unsatisfactory mechanical strength limiting the further practical applications. Herein, we introduce a facile and practical methodology involving the fabrication of self-interlocked poly (vinyl alcohol) (PVA) and conductive Ti 3 C 2 T x MXene networks, then combining them to construct a nanostructure-engineered PVA/MXene membrane. This membrane exhibits superior mechanical strength, in which the tensile strength is about three times higher than the control PVA. Additionally, the membrane demonstrates outstanding fire-resistant performances with an 80% reduction of peak heat release rate than pure PVA. More importantly, this unique membrane with random conductive networks possesses an outstanding EMI shielding efficiency near 41 dB much greater than traditional composite, which meets the requirement of high-efficiency EMI shielding applications. This article displays a novel strategy to fabricate a nanostructured polymer membrane with outstanding fire resistance, electrical conductivity, and mechanical strength, targeted and designed for high-efficiency EMI shielding applications. [ABSTRACT FROM AUTHOR]