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Lightweight wood‐plastic composites (WPC) are made from expandable polystyrene and wood particle using a mold foaming technique, and their fire resistance is improved with the addition of melamine phosphate (MPP) and aluminum hypophosphite (AHP). Flame retardancy is characterized and shown to be significantly enhanced on limiting oxygen index (LOI), vertical burning test (UL‐94), and cone calorimetry tests. The fire behavior investigation indicates that the LOI value of WPC/12MPP/3AHP sample can reach 33.5% and UL‐94 rating was V‐0. The total heat release, total smoke production, peak of smoke production rate and peak of heat release rate of WPC/15MPP are reduced by 23.2%, 47.5%, 28.6% and 17.3%, respectively, compare with the pure one. Mechanical properties characterization of composites also reveals that MPP/AHP has a positive influence on the impact strength, modulus of elasticity and modulus of rupture. [ABSTRACT FROM AUTHOR]

The preparation of wood products with mechanical reinforcement, flame retardancy, and water resistance is still a problem to be solved. In this work, carbonated apatite (CAp) was bio-mineralized in wood vessel by the method of gradient impregnation. The CAp@wood75G sample with the weight gain of 75 wt% showed the greatest bending strength and compressive strength due to the formation of organic–inorganic composites. With the high bending strength and compressive strength, the CAp@wood75G sample exhibited elevated limiting oxygen index (LOI) of 60.4% and self-extinguished immediately in the vertical burning test. In cone calorimetry test, the peak of heat release rate and total heat release for CAp@wood75G sample were lessened by 68.2 and 53.1% respectively, compared with that of natural wood sample. Furthermore, the LOI of CAp@wood75G with self-extinguishment was still as high as 38.4% even after immersed in water for 24 h. Furthermore, the flame retardant mechanism was explored and generalized. The CAp was decomposed to produced CO2 and H2O to dilute the combustible gases in the air, and catalyzed wood to form the barrier of heat and oxygen during burning. Moreover, CAp produced inorganic salts which played the protective layer role. To conclude, this efficient processing method by bioinspired mineralization was eco-friendly and effective. [ABSTRACT FROM AUTHOR]

Nylon-cotton (NYCO) blend fabrics have been widely used recently; however, they are susceptible to ignition when exposed to flame. Herein, 3-glycidyloxypropyl trimethoxy silane (GPTMS) associated with polyethyleneimine (PEI) and phytic acid (PA) was incorporated on NYCO fabrics through the facile sol–gel and dip-nip-dry method to prepare flame retardant NYCO fabrics with enhanced washing durability. The limiting oxygen index (LOI) value of treated NYCO fabrics was increased from 18.5 to 29.8% and the damaged length was reduced from 30 to 7.5 cm. Cone calorimeter test indicated that the peak heat release rate and total heat release were decreased by 73 and 79% respectively, compared with that of the control NYCO fabrics. The flame retardancy was well maintained and showed self-extinguishing behavior after 20 laundering cycles. The char formation ability was reinforced and the possible flame retardant mechanism was proposed. Moreover, the dermal irritation test showed good biological safety of the fabrics, which were incapable to cause erythema and edema on rabbit skin. This study proposed a feasible method to produce flame retardancy, durability, and bio-safety nylon-cotton blend fabrics by textile finishing. [ABSTRACT FROM AUTHOR]

Polyethylene terephthalate (PET) fabric has been widely used in textile industry for decades. However, it faces poor flame retardant performance and dripping problem during burning. In our study, a novel intumescent flame retardant coating containing bio‐materials ammonium phytate (APA) and cyclodextrin (CD) had been constructed on PET fabrics surface via pad‐dry‐cure method. The fire performance, mechanical properties and bio‐safety of APA/CD coated fabric were evaluated. PET fabric coated with 19%APA/6%CD showed a limiting oxygen index value of 29.5% with self‐extinguish from fire and no melt dripping during the vertical burning test. Cone calorimetry test revealed that treated PET fabric significantly suppressed heat release and mass loss. The peak heat release rate was decreased from 277.1 KW/m2 of PET fabric to 158.3 KW/m2 of PET‐19%APA/6%CD sample. Furthermore, the residue of treated fabric after combustion was also increased significantly. Tensile strength test showed that the maximum force of fabric was improved by 109.5% in warp direction and 24.2% in weft direction after treatment. Skin irritation test indicated that APA/CD coated PET fabric did not cause erythema and edema to rabbit skin and exhibited satisfactory bio‐safety. All these results suggest that this study proposes a viable way to produce bio‐safety flame retardant PET fabrics. [ABSTRACT FROM AUTHOR]

As a bio‐based and biodegradable textile, poly (lactic acid) (PLA) nonwovens are an important supplement for nature cotton, flax, and silk. This work concentrated on improving the flame retardancy of PLA nonwovens by introducing a novel eco‐friendly flame retardant (TPA), which was synthesized from phytic acid and tris(hydroxymethyl)methyl aminomethane. The structure, composition, and properties of TPA were fully characterized, and the results showed that TPA owned excellent thermal expansion performance. The flame retardancy of PLA nonwovens was efficiently improved by the presence of TPA. For PLA/23%TPA sample, the molten droplet was inhibited and the damaged area was decreased by 71.8%. The LOI value was increased from 18.0% of control PLA to 26.5%, and the peak heat release rate (pHRR) and total heat release rate (THR) were decreased by 30.2% and 29.0%, respectively. Besides, TG analysis confirmed a great char‐forming capability of the treated fabrics with the residue amount increasing from 1.8 to 11.6 wt% at 800°C. TPA released vapor, phosphorus radicals into the gas phase, and also promoted to form a compact char barrier in the condensed phase, which enhanced the carbonization and flame retardancy of PLA nonwovens. To our best knowledge, our work is one of the few studies focused on the flame retardancy of bio‐based PLA nonwovens. [ABSTRACT FROM AUTHOR]

Bamboo fibers (BF) were used as charring agent in thermoplastic polyurethane (TPU), together with ammonium polyphosphate (APP) to prepare intumescent flame retardant composites. In order to improve the dispersibility and flame retardant efficiency, BF was grafted with diammonium phosphate (DAP), named as modified bamboo fibers (M‐BF). By the presence of 8 wt% APP and 2 wt% M‐BF, the sample could achieve the maximal limiting oxygen index (LOI) value of 30.5% and V‐0 rating in UL‐94 test. The peak heat release rate for TPU/8APP/2 M‐BF is 190 kW/m2, which is 86.0% lower than that of neat TPU. Besides, TPU/8APP/2 M‐BF sample presented a tensile strength of 23.0 MPa, which was slightly lower than neat TPU sample. The thermogravimetric analysis for TPU composites and the morphology observation of the char demonstrated that APP and M‐BF took effects on condensed phase through promoting the formation of intumescent char structure and free radical trapping. Meanwhile, it could release inert gases in gas phase. Therefore, M‐BF exhibited great potential in applying as renewable charring agent for alleviating the depletion of petroleum resources. [ABSTRACT FROM AUTHOR]

Expandable graphite (EG) and modified multi‐wall carbon nanotubes (ATH‐MWNT) were introduced to expandable polystyrene (EPS) foams in order to improve its fire performance. The fire performance of EPS foams was evaluated by limiting the oxygen index (LOI), vertical burning (UL‐94), and cone calorimetry tests. The results showed that the presence of 14.3% EG and 4.1% ATH‐MWNT increased the LOI value from 18.0 to 30.3%, upgraded the UL‐94 rating from no rating to V‐0, completely eliminated melt dripping, and significantly decreased the peak heat release rate from 933 to 177 kW/m2. Thermal analysis indicated that the thermal stability and char formation were improved by the presence of flame retardants. The char morphology was characterized by scanning electronic microscopy (SEM). It was suggested that the presence of EG and ATH‐MWNT could form integrated char layers during combustion, which was beneficial to the formation of an intumescent protective char structure. [ABSTRACT FROM AUTHOR]

Flame retardant expandable polystyrene (EPS) foams were prepared by coating method. Red phosphorus (RP) and expandable graphite (EG) were chosen as the flame retardants to be coated on the surface of expanded PS beads. By the presence of 33 phr RP/EG with a mass ratio of 1:1, the limiting oxygen index of EPS foam could reach up to 26.9%, with V‐0 rating obtained in UL‐94 test. The peak heat release rate could also decrease to 180.67 kW/m2, which was 72.9% lower than that of neat EPS sample. Thermogravimetric analysis revealed an obvious increase of thermal stability and residue char amount by the presence of RP and EG. From the observation and analysis of char residue, it could be proposed that there existed a significant synergistic effect between RP and EG. RP could be oxidized and further react with graphite by the presence of oxygen at high temperature, forming isolated char layer and releasing nonflammable gases. Moreover, P radicals were generated at high temperature and could capture the radicals formed during the combustion of polystyrene and eliminate the burning chain reactions. [ABSTRACT FROM AUTHOR]

A novel intumescent flame retardant (IFR) combination containing ammonium polyphosphate (APP)/p- aminobenzene sulfonic acid modified melamine (AM)/Chitosan (CS) was coated on cotton fabric surfaces via layer-by-layer self-assembly. The fire performance, softness and bio-safety of the treated fabric were evaluated. Fabrics prepared with 15 self-assembly layers of AM-CS/APP had a limiting oxygen index value of 31.5%. Analysis of the cone calorimetry data revealed that the treated fabrics significantly suppressed heat release and mass loss. It was demonstrated that cotton fabrics exhibited a peak heat release rate (pHRR) value of 162.2 kW/m2 and total heat release (THR) value of 17.7 MJ/m2, while the treated fabrics showed pHRR of 98.6 kW/m2 and THR of 7.1 MJ/m2, dropped significant decrease of 40% and 60%, respectively. Furthermore, our results showed that only 8.1 wt% residue remained for the control cotton sample vs. 24.1 wt% for the treated after cone test. Cytotoxicity evaluation indicated bio-safety of the AM modified was much better than that of APP. In addition, the APP/AM/CS coating had minimal negative impact on the mechanical property of the resulting material. These result suggest cotton fabrics treatment proposed in this study provides a feasible way to produce environmentally friendly flame retardant cotton. [ABSTRACT FROM AUTHOR]

Cellulose microcrystalline (CMC), a linear polysaccharide with glucosidic bond, was successfully extracted from bamboo powder and modified by 3‐aminopropyltriethoxy silane coupling agent (KH550) to prepare KH550‐CMC. The prepared KH550‐CMC, in association with ammonium polyphosphate (APP), was introduced into epoxy resin (EP) by casting process to obtain flame retardant composites. The fire performance evaluation indicated that the presence of 10‐phr APP and 5‐phr KH550‐CMC in EP achieved the maximal LOI value of 28.9%, passed the UL‐94 V‐0 rating, and significantly decreased the peak heat release rate from 1055 kW/m2 of neat EP to 286 kW/m2. The improved fire performance is due to the improvement of dispersity of CMC in EP matrix and formation of better char layer, thus protecting the matrix effectively. Moreover, the introduction of KH550‐CMC could also partly eliminate the negative influence of flame retardants on the mechanical properties of EP composites due to the strengthening effect of CMC and better interfacial compatibility after modification with KH550. [ABSTRACT FROM AUTHOR]

Microcrystalline cellulose (MCC) extracted from bamboo powder was used as bio-based carbon source in intumescent system. Before using, MCC was modified with methacrylic acid (MA) by grafting polymerization to prepare MA-MCC, which may improve both the dispersibility and compatibility of in/with polylactic acid (PLA). MA-MCC, together with ammonium polyphosphate, was blended into PLA by melt compounding. The flame retardant properties of the composites were characterized by the limiting oxygen index (LOI), UL-94 vertical burning test and cone calorimeter test. The results showed that the LOI of PLA composite sample containing 3% MA-MCC and 7% APP could reach up to 26.8% and pass V-0 rating in UL-94 test. The addition of APP and MA-MCC could also decrease the peak heat release rate from 556 kW/m2 of neat PLA to 456 kW/m2 and form a continuous, dense, homogeneous residue char to prevent PLA from further burning. Thermogravimetric analysis showed that the presence of APP and MA-MCC could enhance the thermal stability of the composites, which is also essential for the improvement of fire performance. The mechanical properties of PLA composites were also improved with the unnotched impact strength increased to 8.16 kJ/m2 and Young's modulus increased to 1612.8 MPa. The possible mechanisms for the improvement of flame retardancy and mechanical properties had also been proposed. [ABSTRACT FROM AUTHOR]

Nitrate intercalated hydrotalcite (NO3−‐HTC) was first prepared as precursor; a schiff base derivative containing N, P, and S was synthesized and its structure was characterized. Later the schiff base derivative was used as intercalation to replace NO3− in hydrotalcite. The final product was schiff base derivative intercalated hydrotalcite, which was named as benzaldehyde–taurine–hypophosphorous (BTP)‐HTC. The results showed both NO3−‐HTC and BTP‐HTC can effectively improve the flame retardant and thermostability of ethylene vinyl acetate (EVA). In cone calorimeter test, the peak heat release rate of EVA was 1421.2 kW/m2 and reduced sharply to 746.1/584.5 kW/m2 for 20 wt% NO3−‐HTC/BTP‐HTC adding, respectively. At same time, the total heat release was also decreased from 120.6 MJ/m2 for EVA to 81.0/70.0 MJ/m2, respectively. Morphology observation and composition analysis by scanning electron microscopy (SEM)/X‐ray spectroscopy (EDS) documented the residue left after combustion of EVA/NO3−‐HTC was just ash containing Mg and Al; but for EVA/BTP‐HTC, coherent char layer containing Mg, Al, and P was left. Thermogravimetric analysis indicated that the thermal degradation of EVA was prolonged by either NO3−‐HTC or BTP‐HTC; and char content was kept to 8.6% and 11.0%, respectively. The whole results documented either NO3−‐HTC or BTP‐HTC improved the combustion behavior and thermostability of EVA, and BTP‐HTC showed excellent effect. J. VINYL ADDIT. TECHNOL., 25:255–261, 2019. © 2018 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

In this work, a novel sulfur‐based flame retardant (SA‐M) was synthesized by the self‐assembly of melamine and sulfamic acid. The chemical structure of SA‐M was fully characterized. SA‐M, in company with Al2O3, was then introduced into polyamide 11 (PA 11) by melt compounding in order to improve the fire resistance of the polymer substrate. The observation by scanning electron microscopy (SEM) and electron probe microanalysis (EPMA) indicated the well dispersion of SA‐M in PA 11 matrix. The fire performance of PA 11 composites was evaluated by limiting oxygen index (LOI), vertical burning (UL‐94), and cone calorimeter tests, respectively. The results showed that the presence of 17.5% SA‐M and 2.5% Al2O3 increased the LOI value from 22.4% to 30.9%, upgraded the UL‐94 rating from no rating to V‐0, significantly eliminated the melt dripping, and decreased the peak heat release rate from 1024 to 603 kW/m2. The thermal behaviors were investigated by thermogravimeric analysis (TGA) and TGA‐Fourier transform infrared spectroscopy (FTIR). It was suggested that SA‐M took effects mainly in gas phase by diluting the combustible fuel, leading to the improvement of the fire resistance of PA 11. [ABSTRACT FROM AUTHOR]

[Display omitted] Despite the advantages of easy moulding and excellent mechanical properties, there are still some shortcomings with polypropylene (PP) such as high flammability and poor ultra-violet (UV) resistance. In this work, modified zinc oxide (mZnO) was prepared by reacting zinc oxide nanoparticles (ZnO) with polysiloxanes, and the effect of mZnO on the effectiveness of intumescent flame-retardant and on the UV aging resistance of polypropylene were investigated. By introducing 16 wt% (intumescent flame-retardant /mZnO) and 0.3 wt% maleic anhydride-grafted PP (MAH-g-PP), the limiting oxygen index increased to 32.7 %, and passed UL-94V-0 rating. In comparison to the controls, the peak heat release rate and the peak smoke release rate were 88.5 % and 80 % lower, respectively. In addition, PP samples showed improved mechanical properties, with a 5 % increase in tensile properties compared to the pure PP sample. After 100 h of UV irradiation, the surface of the samples was relatively flat and smooth, and the carbonyl index decreased from 81.1 of neat PP to 26.7. PP composites with 100 h aging treatment still had excellent flame retardancy and mechanical properties. The results showed that mZnO was effective in improving the flame retardancy, mechanical properties and light aging tolerance of PP. This study provides a novel approach to fabricate long-life flame-retardant PP composites with low additive content. [ABSTRACT FROM AUTHOR]

• The trinity monocomponent intumescent flame retardant (IFR) named TAPP was successfully synthesized by microencapsulating the ammonium polyphosphate (APP) with 1, 10-diamino-decane (DA) and tannic acid (TA). • The addition of microencapsulated TAPP significantly enhanced the flame retardancy of polypropylene (PP). • UV resistance of PP composites was also improved due to the introduction of TAPP. Polypropylene (PP) has the advantages of excellent mechanical properties and easy molding, but its shortcomings such as high flammability and poor ultraviolet (UV) resistance cannot be ignored. In this paper, APP was used as the core, 1, 10-diamino-decane (DA) was used as a "bridge" to connect TA to the surface of APP, obtaining TAPP through oxidation self-polymerization. The addition of TAPP greatly improved the flame retardancy and UV resistance of PP matrix. The limiting oxygen index of the PP/22.5 %TAPP sample was increased to 31.0 %, and it was able to pass the UL-94 V-0 rating without droplet produced. Compared with PP samples, the peak heat release rate and peak smoke release rate of PP/22.5 %TAPP sample were reduced by 65.0 % and 44.7 %, respectively. In addition, the tensile strength and impact strength of PP/22.5 %TAPP samples decreased by only 2.7 % and 15.0 % after 60 h UV irradiation. The results showed that the addition of TAPP effectively improved the flame retardancy and UV aging resistance of PP. This study provides a feasible method for the preparation of anti-UV aging and flame-retardant PP composites. [ABSTRACT FROM AUTHOR]

Cotton fabric has extensive application due to its comfort and breathability. However, the inherent flammability limits its wide application. Durable polysaccharide-based flame retardants with a low impact on the softness of fabrics are rarely reported. In this work, a novel flame retardant ammonium phosphate of lentinan (APLNT) was synthesized and grafted on the surface of cotton fabric. The treated cotton fabric had a high limiting oxygen index (LOI) value of 43.3 % and passed the vertical burning test (VBT) with a 21.1 % weight gain of APLNT. Compared with control cotton, the peak heat release rate and total heat release values of Cotton-APLNT 2 decreased by 92.8 % and 50.9 %, respectively. In addition, the cotton fabric still passed the VBT and kept an LOI value of 27.0 % even after 50 laundering cycles, indicating that the fabric can be used for daily needs. More importantly, the treated fabric remains soft. This research provided a new strategy for preparing bio-based durable flame retardant cotton fabrics. [Display omitted] [ABSTRACT FROM AUTHOR]

In this study, a novel bio-based flame retardant LC-PA is prepared by the Mannich reaction between phytic acid (PA) and L-citrulline (LC). LC-PA is combined with tannic acid (TA) and introduced into PLA to improve fire performance and accelerate biodegradability. Compared with control PLA, the PLA composite containing 10% LC-PA/TA increases the LOI value to 26.9%, reaches a V -0 rating in the UL-94 test, and reduces the peak heat release rate and total heat release by 24.5% and 21.1%, respectively. More importantly, the introduction of LC-PA/TA accelerates the degradation rate of PLA in soil, which is of significance for biodegradable materials. The addition of LC-PA/TA can attract water and provide a suitable energy source for microbial proliferation, accelerating the hydrolysis and microbial degradation of PLA. This work provides a practical approach for high flame retardancy and rapid biodegradability in the soil to the bio-based polymer. [Display omitted] • A fully bio-based multifunctional additive (LC-PA/TA) has been synthesized. • 10%LC-PA/TA imparts a desirable flame retardancy to PLA. • LC-PA/TA improves the degradation rate of PLA in the soil. [ABSTRACT FROM AUTHOR]

Polycarbonate (PC) is known for its high impact resistance and transparency. However, fabricating flame-retardant and scratch resistant PC without sacrificing its mechanical properties and transparency remains a great challenge. Herein, we prepared a highly transparent and fast curing coating (DA-AE) composed of imidazole-based flame-retardant curing agents (DA) and epoxy-oligosiloxane (AEOS) via imidazole-induced anionic polymerization. The curing time of DA-AE coating was only 8 min at 130 °C. The presence of the coating significantly improved the flame retardancy and scratch resistance of PC films. In contrast to the uncoated PC films, the PC/DA-AE sample self-extinguished within 1.2 s in the vertical burning test and achieved a limiting oxygen index of 27.1 %. In the cone calorimeter test, the PC/DA-AE sample exhibited a notable 49.1 % reduction in the peak heat release rate compared to that of the PC films. Additionally, the pencil hardness of PC/DA-AE-2 was increased to 6H from 2B of the control PC film. The coating exhibited good adhesion to the PC substrate and achieved the highest grade in the cross-cut test without any surface pre-treatment. Remarkably, the coating showed strong chemical and mechanical stability during tests of wiping cycles with different solvents and bending cycles. This work provided a simple and efficient strategy for large-scale producing transparent flame-retardant and scratch resistant PC films. [Display omitted] • A transparent and flame-retardant coating (DA-AE) was prepared via imidazole-induced anionic polymerization. • The DA-AE coating simultaneously improved the surface hardness and flame retardancy of PC films. • The coated PC films showed high transparency, solvent wiping resistance and good flexibility. [ABSTRACT FROM AUTHOR]

• By foam finishing with sodium polyborate, cotton fabric obtains good flame retardancy and maintains softness and breathability. • The flame retardant does not involve Cl or P-containing chemicals. • Foam finishing consume lower water or solvent than dip-padding finishing. The conventional process of imparting flame retardancy to cotton fabrics requires the consumption of large amounts of water, chemicals, and energy, which usually involves halogen-containing and phosphorus-containing chemicals. In this work, an eco-friendly sodium polyborate (SPB) foam was creatively introduced onto the cotton fabric surface by a bladed coater to improve the fire resistant performance. For the cotton sample with only 6.7% weight gain (WG) of SPB coating, the LOI value of cotton fabric (SPB treated cotton-1) was enhanced to 32.6% from 18.5%, the damaged length was decreased to 5.7 cm, and the sample self-extinguished in the vertical burning test. The peak of heat release rate value, total heat release value, and total smoke production (TSP) value decreased by 87.0%, 72.7%, and 22.2% respectively compared with those of the control sample. The TSP was further decreased by 80.6% when the WG of SPB was 16.7%. Besides, the SPB treated cotton showed enhanced antibacterial activities against S.aureus and E.coli. Particularly worth mentioning is in the SPB foam finishing procedure, no organic solvent and P or Cl-containing chemicals were involved, and the processing time was only around 3 min with obviously reduced water consumption, compared with dip-padding finishing. More importantly, SPB treated cotton kept good softness, whiteness, water vapor permeability, and air permeability. The SPB foam finishing in this work shows considerable potential in realize good flame retardancy on cotton fabrics by eco-friendly and high-efficient strategy. [ABSTRACT FROM AUTHOR]

• A 3D boron nitride skeleton was fabricated by the ice template method. • The thick skeleton layer provides a more efficient heat transfer path. • The synergistic flame retardant mechanism of boron nitride and ammonium polyphosphate was revealed. • The char residue left in the combustion can support weights more than 1100 times of its own mass. Epoxy (EP) is widely used in the field of high-speed communication and microelectronics. However, its poor thermal conductivity and high flammability bury the hidden danger of fire accident. In this work, the hexagonal born nitride (h-BN) combined with ammonium polyphosphate (APP) constructs a three-dimensional skeleton (3D-BN) via bidirectional freezing technology. The 3D-BN skeleton is immersed into the EP matrix to obtain the EP/3D-BN composite, which is endowed with high thermal conductivity and flame retardancy. When the loading of hexagonal born nitride (h-BN) is 9.1 vol%, the thermal conductivity of EP/3D-BN 3 composite reaches 1.67 W m−1 K−1, which is increased by 944 % compared with that of the control EP. The peak heat release rate (PHRR) and total heat release (THR) of EP/3D-BN 3 are significantly reduced by 54 % and 34 % respectively. This EP/3D-BN composite provides potential applications toward the industrial production for microelectronic devices. In this work, the hexagonal born nitride (h-BN) combined with ammonium polyphosphate (APP) constructs a three-dimensional scaffold (3D-BN) via bidirectional freezing technology. The 3D-BN scaffold is immersed into the epoxy (EP) matrix to obtain the EP/3D-BN composite, which is endowed with high thermal conductivity and flame retardancy. [Display omitted] [ABSTRACT FROM AUTHOR]

Highly transparent polycarbonate (PC) has received more and more attention. However, several key issues, such as its inherent low flame-retardancy and poor scratch-resistance, are still required to be addressed. Herein, a phosphonamide-siloxane (PPA Si) hybrid coating was synthesized and coated on PC plates via sol-gel methods. The combination of PPA and Si endowed PC with excellent fire performance, the formed Si-O-Si cross-linking network provided hardness and curing capacity, and the PPA increased the flexibility of coating. The coated PC sample showed excellent flame retardancy, good scratch resistance, and high transparency. The PC/PPA-Si-3 sample with a limiting oxygen index of 28.5 % achieved a UL-94 V -0 rating. The peak heat release rate and total heat release of the coated sample were decreased by 56.2 % and 18.3 %, respectively, compared to that of the control PC sample. Meanwhile, the pencil hardness was improved from 2B of the control PC to 2H of the PC/PPA-Si-3 sample, and the coating still maintained good flexibility and adhesion even after being immersed in liquid nitrogen for 20 min. Furthermore, the effect of different ratios of phosphonamide and silicon on the flammability and physical mechanical properties of PC was also investigated. This work has offered a possible strategy to produce transparent, flame-retardant, and scratch-resistant PC plates. [Display omitted] • A transparent and flame-retardant coating was prepared via a sol-gel method. • The organic/inorganic hybrid coating improved the surface hardness of PC plates. • The coated PC showed excellent flame retardancy and good flexibility. • The coating layer formed intumescent char during combustion. [ABSTRACT FROM AUTHOR]

• An eco-friendly coating (APP-LA) was prepared based on ammonium polyphosphate (APP) and tyramine (LA). • The APP-LA treated lyocell showed improved flame retardancy. • The possible flame retardant mechanism of APP-LA was proposed. Low-carbon emissions are a sustainable development approach, among which lyocell is a renewable and zero carbon biodegradable cellulose fiber. The flammability of lyocell fabric poses a threat to people's lives and property. In response to this issue, a bio-based flame retardant, tyramine polyphosphate (APP-LA), was synthesized and applied to the treatment of lyocell fabrics. The synthesis of APP-LA adopted an eco-friendly and organic solvent-free method. In the combustion test, the limiting oxygen index of APP-LA treated lyocell fabrics increased to 35.8% compared to control lyocell (18.5%), and the damage length was only 6.7 cm. Meanwhile, the peak heat release rate and total heat release decreased by 92.9% and 58.7% respectively, compared to the control lyocell. Besides, the P-containing compounds generated by APP-LA accelerated the decomposition of the matrix to produce a dense char layer. The fewer flammable volatiles and more non-flammable gases were released. This work provided a low-cost and eco-friendly strategy for the simple preparation of commercial flame-retardant lyocell fabrics. [ABSTRACT FROM AUTHOR]

[Display omitted] • An eco-friendly coating was prepared by PA-induced polymerization and dipping with AgNWs. • The coated blend fabrics displayed excellent EMI shielding performance. • The coating imparted blend fabrics with antibacterial properties. • The coating maintained a suitable surface temperature for blend fabrics. • The phosphorus-nitrogen synergistic effect improved the flame retardancy of the coating. The functional flexible wearable textiles have a broad application prospect in many areas. However, considering the physical and chemical effects among various additives, it is still a big challenge to prepare wearable fabrics with a balance between different properties. Herein, an eco-friendly and multifunctional nylon/cotton blend fabric was constructed by phytic acid (PA)-induced polymerization of polypyrrole on the surface, followed by dip coating with silver nanowires (AgNWs). A high electrical conductivity of the treated blend fabrics (61 S·m−1) was obtained contributed to the excellent EMI shielding performance of nylon/cotton blend fabric (X-band ∼ 38.8 dB). Meanwhile, the coating maintained the surface temperature of the fabric within a suitable range, resulting in achieving the efficient thermal management. Furthermore, the treated nylon/cotton blends achieved a remarkable reduction (83.3 % and 81.7 %) of peak heat release rate and total smoke production compared to that of the control nylon/cotton blends. In addition, the considerable antibacterial property against E. coli and S. aureus was also realized. The successful application of this simple and eco-friendly method offered the possibility of preparing safer and more versatile wearable smart textiles. [ABSTRACT FROM AUTHOR]

With the increasing requirements of eco-friendly flame retardant fabrics, fully bio-based flame retardants have attracted more and more attention. In this work, a fully bio-based flame retardant coating (PALC) was prepared by combining phytic acid and L-cysteine through ion exchange, which was then applied to nylon-cotton blends. The water contact angle (WCA) test indicates that the hydrophilicity of treated blend fabrics is significantly increased. The treated blend fabrics also exhibited excellent antibacterial property against E. coli and S. aureus. Besides, the limiting oxygen index (LOI) value of the treated blend fabric is increased to 27.2 % from 19.3 %, and the damage length is reduced to 5 cm from 30 cm. The analysis of cone calorimetry test results demonstrates that the total heat release (THR) and peak heat release rate (pHRR) values of the treated blend fabric are reduced by 62.6 % and 65.4 %, respectively, relative to CO/NY. At the same time, the PALC coating can also endow the blend fabric with smoke suppression properties. The total smoke production (TSP) and smoke production rate (SPR) values are reduced by 64.5 % and 67.6 %, respectively. The combination analysis of TG-FTIR, SEM and XPS proves that the phytic acid promotes the dense char layers forming, and L-cysteine generates non-combustible gases. This work provides an eco-friendly and organic solvent-free method for producing flame-retardant nylon/cotton blends with reduced smoke release. [Display omitted] • An organic solvent-free coating PALC was developed from phytic acid and L-cysteine. • PALC coating improved the fire performance of nylon/cotton blend fabrics. • PALC coating increased the hydrophilicity of nylon/cotton blend fabrics. • PALC treated nylon/cotton blend fabrics showed antibacterial property. • PALC acted in both gas-phase and condensed-phase during the combustion. [ABSTRACT FROM AUTHOR]

It is still a big challenge for textile industry in improving fire resistance and reducing melt dripping with minimal loss on the physical properties of polyethylene terephthalate (PET) fabrics. In this work, a highly-effective hyperbranched flame retardant (DT) was first synthesized by ester exchange without using any organic solvent. Then, the DT foam was prepared and blade coated on PET fabric to improve the fire performance. The prepared PET fabric with only 2.7% weight gain of DT was self-extinguished and did not produce any molten dripping during the vertical flammable test. The peak heat release rate and total heat release of the PET fabric sample with 19.4% DT were decreased by 42.0% and 57.1%, respectively compared with that of the control PET. Besides, the as-prepared PET fabric sample showed better physical properties such as breaking strength, vapor permeability, air permeability, antistatic property, and softness than the control PET fabric sample. The DT foam finishing process did not involve any organic solvent and consumed less water and energy compared with conventional fabric treatments. It is expected that this work provides a facile and eco-friendly strategy for fabricating flame retardant PET fabric with excellent comprehensive performances. [Display omitted] • A hyperbranched flame retardant (DT) was synthesized by a solvent-free approach. • Flame retardant PET fabrics were prepared by sustainable foam finishing. • The PET fabric with 2.7% DT was self-extinguished and free of molten drops. • The treated PET fabric showed excellent physical properties. [ABSTRACT FROM AUTHOR]

• Two reactive flame retardants were obtained through transesterification. • The flame retardants improved the flame retardancy of rigid polyurethane foam. • The mechanical properties and low heat conductivity were well maintained. The reactive type flame retardants have been applied in rigid polyurethane foams (RPUF) owing to their excellent durability and minimal negative effect on the physical properties, however, their flame retardant efficiency cannot meet the requirements in many practical application scenarios. In this work, two reactive-type flame retardants with several hydroxyl groups were synthesized by a solvent-free transesterification between erythritol and dimethyl methyl phosphonate (DMMP), and they were then introduced into RPUF by reacting with isocyanate respectively. The flammability of the as-prepared RPUF samples was evaluated by limiting oxygen index (LOI) and cone calorimeter tests. With the presence of 10 phr as prepared flame retardant, the LOI value of RPUF was improved from 18.3% to 29.8%, and the peak heat release rate (pHRR) and total heat release (THR) were reduced by 31.4% and 47.8% respectively in contrast to that of control RPUF. Furthermore, the compressive strength and thermal conductivity of RPUF containing reactive flame retardants were similar to those of control RPUF. This study provides an innovative method for the clean production of commercial RPUF with fire safety by using a modified phosphorus ester. [ABSTRACT FROM AUTHOR]

[Display omitted] • Formaldehyde-free durable flame-retardant cotton fabrics were prepared. • The fabric had an LOI of 35.3% and was self-extinguishing after 300 washing cycles. • The durability was reinforced by the interface polymerization of PEI and TMC. Due to fire hazards and environmental concerns, considerable attention has been paid to the design of durable flame retardant fabrics. In this work, a formaldehyde-free flame retardant cotton fabric (Cotton-PEI/APP-TMC) with ultra washing durability was prepared via covalent bonding of ammonium polyphosphate (APP) and polyethyleneimine (PEI) followed by the interface polymerization between PEI and trimesoyl chloride (TMC). The prepared fabric exhibited excellent flame retardancy with a limiting oxygen index value (LOI) of 42.0 % and a damaged length of less than 40 mm in the vertical flammability test (VFT). Besides, the cotton-PEI/APP-TMC sample was not ignited in the 50 kW/m2 cone calorimeter test with a dramatic decrease in both the peak heat release rate and total heat release. Even after 300 washing cycles, the cotton-PEI/APP-TMC sample had an LOI value of 35.3 % and was still self-extinguishing in VFT. It was demonstrated that the interface polymerization between PEI and TMC stabilized the flame retardant coating and shielded the Na+ during washing cycles, which endowed the fabric with durable flame retardancy. It is expected this work paves a promising application prospect for the fabrication of bio-safe durable flame retardant cotton fabrics. [ABSTRACT FROM AUTHOR]

High efficient flame retardant surface treatment through a simple and universal strategy has attracted considerable interest. In this work, polyphosphonamide (PPA) was synthesized via an eco-friendly amine ester exchange reaction, and then the polydopamine-polyphosphonamide (PDA-PPA) coating was constructed by a mussel-inspired phenol-amine co-deposition on the surface of various substrates (cotton, polyethylene terephthalate, poly (lactic acid), polyamide, polypropylene fabrics, and flexible polyurethane foam). It was demonstrated that the PDA-PPA coating significantly improved the flame retardancy of the six substrates. For example, in the case of PDA-PPA coated cotton fabric sample, the limiting oxygen index was increased to 28.3%, the peak of heat release rate and total heat release was decreased by 70.6% and 48.2%, respectively. Especially in the vertical and horizontal burning tests, all PDA-PPA coated samples were self-extinguished and free of molten droplets. It was suggested that the PDA-PPA coating released P-containing radicals to capture active small free radicals and released non-combustible gases to dilute combustible volatiles in the gas phase. In addition, the coating showed excellent intumescent charring ability and promoted the char formation of all substates except polypropylene. Surprisingly, the coating also improved the breaking strength of the PDA-PPA coated fabric and the compressive stress of the PDA-PPA coated foam samples. It was believed that this work provides a scalable and promising strategy for preparing fire safety polymeric materials with a large specific surface area. [Display omitted] • Polyphosphonamide (PPA) was synthesized by an eco-friendly approach. • Polydopamine (PDA) -PPA coating was constructed on the surface of six substrates. • All PDA-PPA coated samples were self-extinguished and free of molten droplets. • The PDA-PPA coating exerted a comprehensive inhibition on combustion. • A facile, universal strategy for flame retardant surface treatment was proposed. [ABSTRACT FROM AUTHOR]

• Divinylbenzene-maleic anhydride microsphere (DM) was used as a synergistic flame retardant and compatibilizer. • By incorporation of 16wt% intumescent flame retardant (IFR) and 1wt% DM, the bio-based and degradable polyester P34HB reached UL-94V-0 grade. • The smoke and toxic gas release were obviously reduced by 1wt% DM. • The degradation rate of P34HB/16wt%IFR/1wt%DM was more than 5 times faster than the control P34HB. Poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P34HB), as a bio-originated and biodegradable polyester, is expected to be developed to substitute traditional petroleum-based plastics. However, its flammability restrains its application, intumescent flame retardant (IFR) has been used in P34HB. Herein, a rigid microsphere divinylbenzene-maleic anhydride (DM) copolymer was used as a synergistic agent with IFR together in P34HB. The LOI of the 83wt% P34HB/16wt% IFR/1wt% DM reached 30.0%, and the composite also passed the UL-94V-0 rating. In the cone calorimeter test, the peak heat release rate (PHRR) of the control P34HB was 727 kW/m2, which was reduced to 281 kW/m2 for the 83wt% P34HB/16wt% IFR/1wt% DM. The total smoke production (TSP) of the control P34HB was 12.1 m2, however, the TSP value of 83wt% P34HB/16wt% IFR/1wt% DM was reduced to 8.4 m2. The results showed that DM acted as an ideal synergist flame retardant. For the 75wt% P34HB/25wt% IFR, the tensile strength and impact strength were 13.7 MPa and 4.2 KJ/m2, respectively and for the 83wt% P34HB/16wt% IFR/1wt% DM, they were increased to 18.1 MPa and 9.1 KJ/m2, respectively. In the degradation process, the weight loss rate of control P34HB was 0.1 mg/h, and that was 0.56 mg/h for 83wt% P34HB/16wt% IFR/1wt% DM, which indicated that the IFR/DM accelerated the degradation of P34HB. All the work documented that DM improved the flame retardant, mechanical properties, and degradation rate of P34HB. [ABSTRACT FROM AUTHOR]

The flammability of nylon/cotton blend fabrics poses a great potential to cause fire hazard. A bio-based boron contained flame retardant (PBN) in this work was obtained, and then was applied in association with phytic acids to nylon/cotton blend fabrics using a facile dipping and nipping method. The flame retardancy of the fabric was improved significantly with reduced phosphorus content at the presence of PBN. The LOI of the PBN treated blend fabric was 30.1%, and the peak heat release rate (pHRR) and total smoke production (TSP) were decreased by 46.0% and 71.8% compared with that of control blend fabric in the cone calorimeter test. The analysis of the char residue proved the polyphosphoric acids in the flame retardant accelerated the formation of the char, while the ceramic boron structure remained in the char to stabilize the char layer. Moreover, it was suggested that the release of inert gases, such as NH 3 and H 2 O diluted the combustible volatiles in the gas phase. This work proposes a possibility for the production of bio-based nylon/cotton blend fabrics with flame retardancy. [Display omitted] • A bio-based flame retardant coating was prepared by ion exchange reaction. • B element was introduced into the coating to play a synergistic effect. • Bio-based phytic acids promoted the formation of protective char layer. • The coating improved the flame retardancy and suppressed smoke release. [ABSTRACT FROM AUTHOR]

The incorporation of biological resources for developing flame retardant is a promising approach to fabricate durable flame retardant fabrics. Herein, a novel bio-based flame retardant ammonium salt of taurine phosphonate (PTau) was successfully synthesized from taurine and grafted onto the nylon-cotton (NYCO) blend fabrics by covalent bonds. Both the flame retardancy and washing durability of PTau treated NYCO fabrics were improved significantly. The limiting oxygen index (LOI) value of PTau-NYCO fabric was increased from 18.5 % to 36.7 % and the damaged length was reduced from 30.0 cm to 5.6 cm during the vertical burning test. The flame retardancy of PTau-NYCO fabric was well preserved with the LOI value of 29.2 % after 40 laundering cycles. Cone calorimeter test indicated that the PTau-NYCO fabric decreased the peak heat release rate from 207.7 kW/m2 to 77.5 kW/m2, and the total heat release rate from 10.5 MJ/m2 to 5.6 MJ/m2, respectively, compared with that of the control NYCO fabric. Thermogravimetric analysis test showed that the char formation ability was improved for PTau-NYCO fabric with the char residue of 37.2 wt% at 800 °C. The flame retardant mechanism showed that PTau was beneficial to form the char layer and generate nonflammable gases. In general, this work proposes a feasible method to produce durable flame retardant NYCO fabrics by using taurine derivatives. [Display omitted] • The bioactive substance of taurine is an eco-friendly and sustainable resource. • Treated nylon-cotton blend fabrics showed improved flame retardancy and excellent washing durability. • The application of taurine provided an effective strategy to reduce the fire hazards of fabrics. [ABSTRACT FROM AUTHOR]

• Phosphorylated histidine-amino triazine-diaminopropane (PHTD) copolymer was synthesized and used as bifunctional additives of flame retardant and binder. • PHTD can improve the flame retardancy and smoke suppression of EPS foams significantly. • The hard shell formed by PHTD can improve the compressive strengths of EPS foams. A novel intumescent flame retardant, phosphorylated histidine-amino triazine-diaminopropane (PHTD) was synthesized and utilized as both a flame retardant and a binder addition. Flame retardant expanded polystyrene (EPS) foams containing PHTD was successfully prepared by coating method. The limited oxygen index (LOI) and vertical burning (UL-94) tests were used to determine the flammability of EPS/PHTD composite foams, and an apparent flame retardant effect could be obtained with up to 28.8% LOI value and UL-94 V-0 rating when 41.9 wt.% PHTD was added. The cone calorimetric test results showed that the treat EPS sample showed significantly depressed peak heat release rate (pHRR) by 74.9% and peak smoke production rate (pSPR) by 77.3%. Additionally, the flame retardant could be evenly coated on the surface of EPS beads. Even though part of the foam was damaged, it could still keep good flame retardant performance. Furthermore, the thermal conductivity of coated foam was not affected and remained at a comparatively low level, and the compressive strength was increased by 20.0%. [ABSTRACT FROM AUTHOR]

• The Ni-Fe layered double hydroxides as synergistic flame retardant fillers were synthesized. • The excellent flame retardant and smoke suppression of TPU was obtained. • The mechanisms for the flame retardancy and smoke suppression were proposed. Aluminum hypophosphite (AHP), as an effective phosphorus-based flame retardant used in thermoplastic polyurethane (TPU), released a large amount of smoke and toxic gasses during combustion. In this work, a flame retardant filler, Ni-Fe layered double hydroxides (NiFe-LDHs), was synthesized and applied in TPU together with AHP. The limiting oxygen index (LOI) of the TPU/6AHP/1NiFe-LDH composite reached 30.7% with a V-0 rating in the UL-94 test. Compared with neat TPU, the peak heat release rate (pHRR) and total heat release (THR) values of TPU/6AHP/1NiFe-LDH sample were reduced by 67.9% and 40.8%, respectively. Moreover, both the smoke production and CO/CO 2 yield were also decreased sharply. It was proposed that NiFe-LDH provided the effect of catalyzing char formation, and the obtained dense char layer was able to block both heat and smoke release. In addition, the addition of NiFe-LDH had little effect on the mechanical properties of TPU, and the tensile strength and elongation at break only decreased by 6.0% and 6.9%, respectively. This work provides a new strategy for fillers and flame retardants to improve the flame retardant properties and smoke suppression of TPU. [ABSTRACT FROM AUTHOR]

• A halogen/phosphorus-free flame retardant phenylboronic acid functionalized chitosan (B-CH) was successfully prepared. • B-CH could effectively improve the flame retardancy of poly(lactic acid). • The char forming ability of PLA composites was also enhanced by the presence of B-CH. A boron-based biological flame retardant phenylboronic acid functionalized chitosan (B-CH) was prepared by reacting chitosan (CH) with 4-formylphenylboronic acids. The structure characterization was carried out by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis. B-CH was added into polylactic acid (PLA) by the melt blending method to improve the fire performance of the composite. The results showed that the peak heat release rate (PHRR) of PLA-7% B-CH decreased to 432 kW·m−2 from 564 kW·m−2 of control PLA. The limiting oxygen index (LOI) was increased from 19.1% to 26.2%, and the vertical burning test (UL-94) could reach a V-0 rating. The B-CH participated in the char formation process, which could generate a continuous compact char layer during the combustion to effectively protect the PLA matrix. This work provided an effective strategy to develop environmental friendly flame retardant PLA composites. [ABSTRACT FROM AUTHOR]

• An organic-inorganic hybrid coating was constructed on T/C fabrics. • The hybrid coating improved greatly the flame retardancy of T/C fabrics. • The coated fabrics showed antibacterial property against S. aureus and E. coli. • The flame retardant and antibacterial mechanism was proposed. In this work, an organic-inorganic hybrid coating was used to improve the fire safety and antibacterial property of polyester/cotton blend fabrics. The hybrid coating was constructed by two steps, including the in-situ growth of zirconium phosphate nanosheets, and the preparation of polyelectrolyte complex with phytic acid and poly(hexamethylene guanidine hydrochloride) via spraying method. The flame retardancy and antibacterial activity of treated fabrics were completely investigated. A self-extinguishing behavior was observed in vertical burning test and the damaged length was only 5.4 cm. The LOI value of treated fabrics was increased from 19.0% of pristine fabrics to 27.8%, and the peak heat release rate and total heat release were decreased by 42% and 27%, respectively. Besides, thermogravimetric analysis revealed that the char residue increased from 8.3% to 26.3% at 800 °C, confirming a great char-forming ability of coated fabrics. Tensile strength test indicates that the introduction of coating had no seriously damage to the mechanical properties of fabric. Moreover, an excellent antibacterial property of treated fabrics was proved by using agar diffusion method. This research provides an environmentally friendly path for the flame retardant and antibacterial modification of polyester/cotton blend fabrics. [ABSTRACT FROM AUTHOR]

The introduction of flame retardants often decreases the ultraviolet (UV) resistance ability of the photo stabilizer. In this work, the antagonistic effect between APP and a light stabilizer HLAS770 was investigated, and the microencapsulated APP (Si-APP) was prepared by coating ammonium polyphosphate (APP) with polysiloxane. Si-APP was introduced into polypropylene (PP) in association with a light stabilizer bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate (HALS770) to synchronously improve both the photo-aging resistance and flame retardancy. The characterization of surface topography, carbonyl index, and mechanical properties demonstrated that the antagonistic effect between APP and HALS770 was eliminated by the presence of polysiloxane. The limiting oxygen index and cone calorimeter test results revealed that the heat and smoke release of aged PP composites containing Si-APP and HALS770 was decreased by 28% and 35% respectively, compared with that of the aged control PP sample, which is crucial to the practical application of PP. It was proved that polysiloxane and HALS770 synergistically improved the photo-aging resistance and flame retardancy of PP. It is suggested that this work provides a new strategy for fabricating long-life flame retardant polypropylene composites. • Si-APP was prepared by microencapsulating APP with a polysiloxane. • Si-APP eliminated the antagonistic effect between APP and HLAS770. • Si-APP showed synergy effect with HLAS770 on delaying photoaging of PP. • HALS770 and Si-APP synergistically improved the flame retardancy of PP. [ABSTRACT FROM AUTHOR]

A novel integrative supramolecular intumescent flame retardant was fabricated by self-assembly of melamine, p -aminobenzene sulfonic acid and phytic acid and was abbreviated as MAP. After chelation with Fe3+ or Zn2+, the resulted products (MAP-Fe and MAP-Zn) were melt-blended with polylactic acid (PLA) to enhance the flame retardancy of PLA. The fire performance was characterized by limiting oxygen index (LOI), UL-94 vertical burning and cone calorimeter tests. The results showed that control PLA was flammable with a low LOI of 20.4%, and it cannot satisfy any UL-94 grade for its severe ignited dripping, whilst the incorporation of 3% MAP-Zn increased the LOI to 29.2％, upgraded the UL-94 rating to V-0, and reduced the peak heat release rate by 18.7%. It was proposed that MAP-Zn mainly promoted the formation of more graphitic carbon in the char residues. In addition, the presence of 3% MAP-Zn slightly reduced the tensile strength of PLA from 64.9 MPa of the control PLA to 60.1 MPa, which met the requirements of most practical applications. • A novel IFR containing P/N/S/Fe/Zn was fabricated by self-assembly. • The novel IFR significantly enhanced the flame retardancy of PLA. • The flame retardant mechanism of IFR was studied. • Explored the different mechanisms of Fe3+ and Zn2+ promoting char formation. [ABSTRACT FROM AUTHOR]

A multi-functional kaolinite-based compound (AST@Kaol) was prepared by successive loading of TiO 2 and SiO 2 to the surface of metakaolinite (Kaol), followed by reaction with γ-aminopropyl triethoxysilane (APTES). The hybrid was then introduced to epoxy resin (EP) to enhance flame retardancy, smoke suppression and anti-aging properties. The results demonstrated the presence of only 3 wt% AST@Kaol can increase the value of limit oxygen index (LOI) of EP composite to 27.3% from 25.3% of neat EP, as well as decrease the value of heat release rate, total smoke release and the smoke density by 36.9, 14.3 and 19.9%, respectively, compared to neat EP. Besides, the thermal stability and thermal oxidative resistance of EP composites was enhanced. The mechanism of fire retardancy, anti-ageing and mechanical of the EP composite containing AST@Kaol was also speculated. [Display omitted] •A kaolinite-based compound (AST@Kaol) was prepared by co-precipitation. • The properties of fire retardant and ageing resistance for EP/3% AST@Kaol were improved. • Fire retardancy and ageing resistance mechanism of EP/3% AST@Kaol was analyzed. [ABSTRACT FROM AUTHOR]

Aluminum hypophosphite (AHP) is an effective flame retardant to thermoplastic polyurethane (TPU), but it also results in increase on smoke release caused by the presence of phosphorus groups. In this work, a novel synergistic flame retardant was fabricated from metal organic framework (ZIF-8) and sepiolite (SEP). For the compsosite of TPU/8.0AHP/1.0ZIF-8@SEP, limiting oxygen index (LOI) reached 27.5% and it satisfied the UL-94 V-0 grade. The heat release rate and the total heat release decreased by 78.9% and 39.1% compared with the control TPU respectively. The increased smoke production caused by AHP was partly adsorbed by ZIF-8@SEP, therefore, the sample of TPU/8.0AHP/1.0ZIF-8@SEP showed the lowest smoke release in cone calorimeter test. Unsimilar as other flame retardant, the using of 8.0AHP/1.0 ZIF-8@SEP just brought less than 2.0% loss on tensile strength and 7.8% drop on the elongation at break of TPU. Consequently, the ZIF-8@SEP was documented as excellent synergistic flame retardant for TPU and it brought limited damage on mechanical performance. [Display omitted] • MOFs@SEP was fabricated and acted well as synergistic flame retardant in TPU/AHP. • Heat release rate of TPU/8.0AHP/1.0ZIF-8@SEP dropped 78.9% compared with solo TPU. • ZIF-8@SEP obviously adsorbed smoke and fatal volatiles produced in fire. • 8.0AHP/1.0ZIF-8@SEP brought little loss on tensile strength and elongation to TPU. [ABSTRACT FROM AUTHOR]

[Display omitted] • A polyelectrolyte (APTris) and ZIF-67 were coated on poly (lactic acid) nonwovens. • The coated fabric had flame retardant, antibacterial and UV-resistant properties. • APTris and ZIF-67 showed excellent synergistic effect in promoting char formation. • ZIF-67 endowed the fabric with antibacterial and UV resistant properties. Eco-friendly bio-based poly (lactic acid) (PLA) non-woven fabrics (NFs) presents great potential to replace petroleum-based fabrics, whereas the attention for preparing multifunctional PLA NFs is still scarce at present. Herein, PLA non-woven fabrics were surface treated by a padding process with polyelectrolyte (APTris) followed by an in-situ growth with zeolitic imidazolate framework-67 (ZIF-67) to improve the flame retardant, antibacterial and ultraviolet (UV) resistant properties. The flammability characterization of the PLA/APTris/ZIF67 fabric sample indicated that the limited oxygen index value was increased to 27.5% from 18.1%. The introduction of APTris/ZIF67 significantly decreased the damaged area, heat release rate, and peak heat release rate of the sample by 83.0%, 33.1%, and 26.4% respectively. It was suggested that APTris and ZIF-67 synergistically promoted the formation of dense char layers, which inhibited the flame spread and reduced the smoke release by adsorption and catalysis effects. Besides, the treated non-woven samples exhibited UV resistant properties and specific antibacterial actions against gram-positive Staphylococcus aureus (S. aureus) and gram-negative Escherichia coli (E. coli). This unique surface modification with the combination of APTris and ZIF-67 provides a new opportunity for manufacturing multifunctional PLA non-woven fabrics. [ABSTRACT FROM AUTHOR]

A self-healing coating containing polyethyleneimine (PEI)/ammonium polyphosphate (APP) polyelectrolyte complex was successfully prepared, and then was deposited on flexible polyurethane foam (FPUF) in association with graphene oxide (GO) via a simple dip-nip process to improve the flame retardancy and mechanical property. The vertical burning test revealed that the FPUF coated with PEI/APP and GO extinguished immediately after removing the igniter. The cone calorimeter results demonstrated that the coating effectively reduced the peak heat release rate by 63.8%. The char analysis suggested that PEI/APP formed an intumescent char structure and released inert gases, whilst GO improved the compactness of the char layer. Furthermore, the compressive strength of the coated foam sample was increased by 175.0% compared to that of the control FPUF sample. The mechanical properties analysis and morphology observation proved that the PEI/APP-GO coating had self-healing ability. This unique intrinsic self-healing coating provides a new opportunity for imparting flame retardancy and excellent mechanical property to foam materials used in many commercial cases. [Display omitted] • PEI/APP-rGO was coated on the foam via a dip-nip process. • The coating improved the flame retardancy and eliminated the melt dripping. • The coating significantly increased the mechanical properties. • The coating showed excellent durability and self-healing ability. [ABSTRACT FROM AUTHOR]

• A phosphate covalent organic framework (PCOF) was successfully synthesized by a facile method. • The introduction of PCOF improved the fire performance of epoxy resin. • PCOF participated in the curing process of EP and thus enhanced the mechanical properties. To prepare epoxy resin (EP) with satisfied fire performance and mechanical properties, a novel phosphoric acid modified triazine covalent organic framework (PCOF) was successfully synthesized. The structure and microtopography of PCOF were fully characterized. By the presence of 12wt% PCOF, the limiting oxygen index value of EP composite was increased from 24.8% to 28.6%, and V-0 rating was achieved in UL-94 vertical burning test. The cone calorimeter test showed that the peak heat release rate and total heat release of the 12PCOF-EP sample were decreased sharply by 78.9% and 68.9% compared with that of the control EP. The flame retardant effect was maintained after soaked in 75 °C for 168 h, indicating an excellent water resistance. The thermogravimetric analysis of the composites indicated that more char residue was formed, especially at a high-temperature range. Moreover, both the tensile and impact properties of EP composites were improved by adding appropriate amount of PCOF. By analyzing the products formed during combustion, it was proposed that PCOF took effects in both gas and condensed phase. [Display omitted] [ABSTRACT FROM AUTHOR]

• Poly-siloxane coated IFR (Si-IFR) was prepared and introduced into TPO composites. • The Si-IFR significantly improved flame retardancy of TPO composites. • The water resistance of TPO composite was enhanced by the presence of Si-IFR. The flammability of thermoplastic polyolefins (TPO) is a prior concern related to fire disasters. The fire safety strategy for TPO has not been settled because of serious waterproof property deteriorations caused by the presence of flame retardant additives. This work reported an encapsulation of conventional intumescent flame retardant (IFR) additives by a poly-siloxane (Si-IFR) and its application in TPO composites. The fire behavior characterization revealed that the peak heat release rate and smoke density of the TPO/Si-IFR sample was decreased by 26.5% and 24.0% respectively compared with that of the TPO/IFR sample. The flame retardant mechanism analysis suggested that the poly-siloxane coated IFR formed compact char layers through Si-O structures and nano-silica attachment on the carbonous layer. Notably, the flame retardancy and mechanical property for the TPO/Si-IFR sample were almost unchanged after being soaked in water for 7 days at 70°C. Consequently, this work proved that the poly-siloxane encapsulated IFR was an effective additive for producing flame retardant and water resistant TPO composites. [ABSTRACT FROM AUTHOR]

In order to guarantee fire safety and water resistance of the butyl acrylate (BA) coating, an integrated intumescent flame retardant (IFR) was fabricated. At first sodium tri-polyphosphate (STPP) was selected as acid source, and melamine (MEL) was gas source. STPP and MEL were connected by ionic bond. In the obtained product of melamine tri-polyphosphate (MTP), the amounts of hydrophilic groups was obviously reduced. BA coating containing 10 wt% MTP showed 37.3% reduction on water absorption, and the surface looked smoother with little folds. The limiting oxygen index (LOI) of BA coating is 22%; comparatively, LOI for BA/10 wt% MTP increased to 27%. The heat release rate (HRR), smoke production rate (SPR), CO production rate decreased by 20.1%, 5.4% and 33.3% respectively. The flame retardancy mechanism was tried to deduce by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM) observation. It was proposed that MTP promoted the formation of compact char and the release of nonflammable gases. [Display omitted] • Melamine reacted with sodium tri-polyphosphate, the product MTP was used as flame retardant. • By 10% adding of MTP, butyl acrylate (BA) coating achieve self-extinguish. • By 10% MTP, heat and smoke release of BA coating was reduced by 38.3% and 27.8%, respectively. • By 10% MTP, the water absorption of BA coating was reduced by 37.3%. [ABSTRACT FROM AUTHOR]

The demand for eco-friendly poly (lactic acid) (PLA) nonwovens grows at a high rate in the past several decades, however, only a little attention has been received for flame retardant PLA nonwoven fabrics. In this work, a novel halogen-free self-intumescent polyelectrolyte tris (hydroxymethyl)-aminomethane polyphosphate (APTris) was synthesized by reacting ammonium polyphosphate with tris (hydroxymethyl) aminomethane, and was then used to improve the fire resistance of PLA nonwovens via a dip-nip process. The flammability characterization indicated the limiting oxygen index value was increased to 30.0% from 18.3%, and the damaged area in the vertical burning test was reduced by about 87.0% by the presence of APTris. The cone calorimeter test results revealed that the peak heat release rate and total heat release of the treated sample were decreased by 41.0% and 28.2% respectively compared with that of the control PLA nonwoven sample. The char residue was increased to 12.3 from 1.7 wt % at 800 °C. It is suggested that the dense char barrier formed at the presence of APTris prevents heat, smoke, and gas transfer, and hence enhance thermal dilatability and flame retardancy of PLA nonwovens. This simple sustainable halogen-free treatment has great potential to produce cleaner commercialized flame-retardant PLA nonwovens. Image 1 • An intumescent polyelectrolyte (APTris) was prepared by ion exchange reaction. • The APTris significantly improved the flame retardancy of PLA nonwovens. • The molten droplet of treated PLA nonwovens was reduced. • The APTris was carbonized to form compact protective layer during combustion. [ABSTRACT FROM AUTHOR]

• A multifunctional coating composed by montmorillonite (MMT)/Laponite (LAP) / polyvinyl alcohol (PVA) was developed. • MMT platelets and LAP rods synergistically formed more compact coating with little cracks. • MMT/LAP/PVA coating gave little attenuation on transparency of PET film. • MMT/LAP/PVA coating with around 800 nm thickness significantly improved fire resistance and oxygen barrier of PET film. A multifunctional nanocoating, consisting of montmorillonite (MMT) / laponite (LAP) / polyvinyl alcohol (PVA), was deposited onto the surface of polyethylene terephthalate (PET) film via a facile co-assembly process. As a result, the PVA/LAP/MMT coating endowed PET film with improved flame retardancy and oxygen barrier. At 4 layers deposition of PVA/LAP/MMT, the film maintained more than 90% transmittance to the visible light. The microscale combustion calorimetry revealed, compared with control PET sample, the peak of heat release rate and total heat release of PET@(MMT/LAP/PVA) 4 sample were reduced by 67.4% and 45.3%, respectively. The oxygen transmission rate significantly reduced at the same time. The reason was speculated at the combination of MMT and LAP, a more compact shielding layer was formed on the PET substrate. [ABSTRACT FROM AUTHOR]

A novel polyhydroxy triazine-based charring agent, N-tris(hydroxymethyl)-amino triazine-piperazine copolymer (TTPC), was synthesized from piperazine, cyanuric chloride and tris(hydroxymethyl) aminomethane. The chemical structure of TTPC was characterized by Fourier transform infrared spectroscopy and 13C solid-state nuclear magnetic resonance. TTPC, ammonium polyphosphate (APP) and zinc borate (ZB) were then introduced into polypropylene (PP) by melt compounding to improve the fire performance of the composites. The test results showed that the presence of 21% APP-TTPC-ZB with mass ratio of 16:4:1 could significantly reduce the peak heat release rate from 1547 to 230 kW/m2, increase the limiting oxygen index value from 18.0 to 29.6% and upgrade the UL-94 rating from no rating to V-0, accompanied by the elimination of melt dripping. The thermal stability and charring behaviors of the composite samples were investigated by thermogravimetric analysis. The results showed that TTPC was a highly efficient charring agent, and ZB could act as synergist in the intumescent system. Based on the comprehensive study of fire performance, char morphology and mechanical properties, it can be concluded that TTPC is a superior charring agent, especially compared with the generally used pentaerythritol. • A novel polyhydroxy triazine-based charring agent (TTPC) was successfully prepared. • With only 21% IFR loaded, the PP composite could obtain a high LOI value of 29.6% and pass V-0 rating with no dripping. • The novel charring agent showed better fire performance than generally used PER. [ABSTRACT FROM AUTHOR]

• A silicone resin/EG surface coated RPUF was prepared via brush painting. • The coated RPUF showed outstanding flame retardancy with an add on of 8.5 mg/cm2. • The mechanical property of coated PRUF was enhanced by the coating. • The durability was investigated under artificial harsh weather conditions. High loading of flame retardants are usually required to prepare fire safety rigid polyurethane foam (RPUF), which often leads to deterioration of its mechanical properties. In this work, a silicone resin (poly-DDPM) was synthesized and coated on the surface of RPUF in association with expandable graphite (EG) via brush painting in order to improve its flame retardancy with minimal damage to the inherent mechanical property. The flammability characterization by limiting oxygen index (LOI), UL 94 and cone calorimeter tests revealed that the fire resistance of the foam samples was significantly improved by the presence of poly-DDPM/EG coating with an average add on of 8.5 mg/cm2. The LOI value was increased to 32.3 from 18, the UL 94 grade was upgraded to V-0, the peak heat release rate and the peak smoke release rate was reduced 55% and 59% respectively compared with that of the control RPUF sample. Additionally, the coated sample could not be ignited when it was exposed to a butane burner for 10 min. The compressive strength of the coated RPUF was impressively increased 10%. Furthermore, the fire resistance of the coating was durable under artificial harsh weather conditions. The poly-DDPM/EG coating adhered on the RPUF surface tightly, and transformed into expanded graphite flakes loaded nano-silica to achieve a protective char layer upon combustion. The demonstrated coated RPUF has great potential for commercial products. [ABSTRACT FROM AUTHOR]

• Ammonium phosphate starch carbamates (APSC) was synthesized. • APSC is used as flame retardant coating for the preparation of EPS foams. • Both the fire performance and smoke suppression are improved by coating with APSC. A novel bio-based flame retardant, ammonium phosphate starch carbamates (APSC) was synthesized from starch, phosphoric acid and urea to achieve better thermal stability and char formation. Flame retardant expandable polystyrene foams (EPS) were prepared by coating method with APSC. The fire resistance evaluation of EPS composites by limiting oxygen index (LOI), vertical burning (UL-94) and cone calorimeter tests indicated that the addition of 47 wt.% of APSC enhanced the LOI from 17.6%–35.2%, with V-0 rating in UL-94, and decreased the peak heat release rate from 666 kW/m2 to 316 kW/m2. Moreover, the total smoke production was also sharply decreased from 70 m2 of pure EPS to 17 m2. By the presence of APSC, the substantial char formation prevented the heat and oxygen transfer, and interrupted the releasing of flammable products, thus protecting the EPS foam from burning. [ABSTRACT FROM AUTHOR]

This work reports our recent effort on the preparation of α-Phenyl-N-(2-propyl-2-hydroxymethyl-1, 3-dihydroxy)-imine-Nickel (Ⅱ) (Ni-MOF) containing polyhydroxy groups and its application in improving the fire performance of PLA composites in combination with ammonium polyphosphate (APP). The flame retardant evaluation revealed that the presence of 1.7% Ni-MOF and 3.3% APP in PLA increased the LOI value to 31.0%, upgraded the UL-94 level to V-0, decreased the peak heat release rate (pHRR), total heat release (THR) and total smoking production (TSP) by 27%, 19% and 50%, respectively, and substantially delayed the time to ignition (TTI) from 67 to 97 s. It was proposed that the flame retardants take effect in both vapor and condensed phases, and Ni-MOF nanosheets can synergistically improve the flame resistance of PLA with APP. The incorporation of Ni-MOF effectively inhibited the deterioration of mechanical properties for PLA composites caused by the presence of APP. • The Ni-MOF nanosheets containing polyhydroxy groups was prepared. • APP and Ni-MOF nanosheets significantly improved the fire safety of PLA composite. • The possible synergistic flame-retardant mechanism of Ni-MOF and APP was proposed. • Ni-MOF effectively improved the mechanical properties of PLA composites. [ABSTRACT FROM AUTHOR]