Search

A 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) derivative is prepared. At first, an intermediate 4,4'‐((triazole)bis(azaneylylidene)bis(2,6‐dimethoxyphenol)) (SGA) is obtained from the Schiff‐base reaction between syringaldehyde (S) and 3,5‐diamino‐1,2,4‐triazole (GA). The further product DOPO‐SGA is then introduced into epoxy by blending to improve flame retardancy and mechanical properties. The flammability evaluation is implemented by limited oxygen index (LOI), UL‐94, and cone calorimeter tests. The presence of 3wt.% DOPO‐SGA increases the LOI to 33.2%, upgrades the UL‐94 rating to V‐0, and reduces the release of smoke and heat of epoxy. The tensile strength and impact strength are also enhanced after the introduction of DOPO‐SGA. The addition of 5% DOPO‐SGA increases the tensile strength and impact strength by 47% and 42%, respectively, compared with that of the control EP sample. It is suggested that the mechanical strengthening is ascribed to the ternary cross‐linked network among epoxy monomer, curing agent, and DOPO‐SGA. This work provides a feasible solution to obtain flame‐retardant epoxy resin with enhanced mechanical performance. [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]

• Bio-based polyester polyol was obtained through one-pot esterification. • The polyol replaced polyether polyols to prepare rigid polyurethane foams. • The flame retardancy of the foam was improved while preserving mechanical properties. A bio-based polyester polyol (BP41) was synthesized through a one-pot esterification and condensation reaction involving bio-based 1,2-propanediol, trimethylolpropane, and adipic acid. The mechanical properties, thermal stability, and thermal degradation behavior of the resulting BP41-based RPUF (PRPUF) were investigated. The prepared RPUF exhibited a density of 47.69 kg/m³, and a compressive strength of approximately 217 kPa. Additionally, it displayed excellent thermal insulation properties, demonstrated by a low thermal conductivity of 0.0261 W/(m·K) and a high initial thermal degradation temperature surpassing 281 °C. Furthermore, the incorporation of 10 % dimethyl methyl phosphonate (DMMP) terminated by erythritol (FRD) into PRPUF led to a limited oxygen index (LOI) of 32.0 % and a UL 94 rating of V-0 in vertical burning tests. The peak heat release rate was reduced by 48.9 %, while the residual char was increased significantly from 6.53 % to 15.82 %. These findings emphasize the considerable potential of the demonstrated bio-based RPUF for various commercial applications. [ABSTRACT FROM AUTHOR]

• Intumescent flame retardant (IFR) and zinc oxide (ZnO) were successfully microencapsulated by polysiloxane. • The addition of microencapsulated IFR and ZnO significantly enhanced the flame retardancy of polypropylene (PP). • Water resistance of PP composites was also enhanced by the presence of microencapsulated IFR and ZnO. Intumescent flame retardant (IFR) and zinc oxide (ZnO) were successfully microencapsulated by polysiloxane, resulting in the preparation of Si-IFR and Si-ZnO, respectively. These microencapsulated additives were then incorporated into polypropylene (PP), leading to a synergistic enhancement of the flame retardancy, mechanical properties, and water resistance. By means of limiting oxygen index (LOI), UL-94 vertical burning test, and cone calorimetry test, an assessment was conducted to analyze the combustion characteristics of PP composite materials containing 2% Si-ZnO and 24% Si-IFR additives. The LOI value and UL-94 of PP/24%Si-IFR/2%Si-ZnO achieved to 39.8% and V-0 rating respectively, with significant decreases in both the total heat release (THR) and total smoke production (TSP). Furthermore, the introduction of polysiloxane significantly improved the water resistance of the PP composites. After a 168-hour water immersion test, notable reductions were observed in water absorption, the precipitation of flame retardants, as well as alterations in the mechanical properties of PP/24%Si-IFR/2%Si-ZnO. [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]

[Display omitted] Lithium-sulfur batteries (LSBs) have become highly promising next-generation secondary lithium batteries owing to their high theoretical energy density and abundance of sulfur. Nevertheless, the large-scale application of LSBs is still restricted by the shuttle effect of lithium polysulfide (LiPSs) and the potential fire hazard caused by flammable electrolytes. Herein, three electrolyte-insoluble brominated flame retardants (BFRs) are selected and coated on both sides of commercial polypropylene separators by a facile slurry coating method. The effects of the three BFRs on the safety and electrochemical properties of LSBs are characterized and compared. The coating modification separators greatly improves the flame retardancy of LSBs through radical elimination mechanism. The self-extinguishing time of the electrolyte is reduced from 0.66 s/mg to 0.20 s/mg. Moreover, it is demonstrated that the oxygen (O)-containing BFRs exert a significant adsorption capacity and are more advantageous than O-free BFRs in LSBs. In addition, octabromoether (BDDP) coated separator is more effective in trapping LiPSs than decabromodiphenyl ether (DBDPO) due to higher O content, which can mitigate the shuttle effect and enhance the cycle and rate performance of LSBs. This simple coating strategy for separators with BFRs offers a strongly competitive option for the large-scale production of high-safety LSBs. [ABSTRACT FROM AUTHOR]

The output of bio-based polyvinyl alcohol (PVA) has been growing rapidly with a substantial increase of developments both in academic and industrial research areas in the past decade, which is due to its water solubility, plasticity, and degradability. However, PVA is highly flammable with a limiting oxygen index of only 19% owning to its inherent macromolecular structure composed of carbon, hydrogen, and oxygen atoms. The demand for flame retardancy of PVA has been increased rapidly and is generally satisfied by introducing flame retardants via chemical grafting, physical blending, and coating. This review summarizes the flame retardants applied in PVA and their influence on the flammability and mechanical properties of PVA materials. The type of flame retardant additives and their application technologies for various PVA products are presented in terms of various PVA products, such as films, aerogel, fibers, foams, and bulk composites. The films dominate the whole research of flame retardant PVA materials owing to their widespread application. The fire performance and flame retardant mechanism are compared and discussed. Additionally, PVA acted as an assistant agent in some polymeric flame-retardant formulations is also discussed and reviewed. [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]

Polylactic acid (PLA) nonwovens, recognized as eco-friendly substitutes for petroleum-based synthetic fibers, face a significant challenge due to their inherent flammability. This work addresses this concern by synthesizing a hyperbranched polyphosphoramide flame retardant (TPDT) through a one-step polycondensation process without using solvent and catalyst. TPDT is subsequently applied to PLA nonwovens using a dip-pad finishing technique. Notably, with a mere 7 wt% weight gain of TPDT, the PLA nonwovens exhibit a substantial increase in the limited oxygen index (LOI) value, reaching 32.3 %. Furthermore, the damaged area in the vertical burning test is reduced by approximately 69.2 %. In the cone calorimeter test, 17 wt% weight gain of TPDT results in a 51.4 % decrease in peak heat release rate and a 56.0 % reduction in total heat release compared to the control PLA. Additionally, char residue increases from 1.5 wt% to 31.1 wt% after combustion. The strong affinity between TPDT and PLA molecules persists even after repeated abrasion, ensuring sustained flame retardancy. Importantly, the introduction of TPDT also imparts increased softness to the PLA nonwovens. This work addresses this concern by synthesizing a hyperbranched polyphosphoramide flame retardant (TPDT) through a solvent-free, catalyst-free, and one-step polycondensation process. [Display omitted] [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]

• 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]

In this work, a sustainable flame retardant and superhydrophobic cotton fabric was prepared by a two-step process: the cotton fabric was firstly treated with a chitosan/sodium polyborate polyelectrolyte complex water solution to obtain a flame retardant layer, and then treated with a polydimethylsiloxane (PDMS) tetrahydrofuran solution to construct a superhydrophobic layer. The phase-separated chitosan with a micro-nano roughness structure was covered by PDMS, which synergistically improved the hydrophobicity of the cotton fabric. The flammability evaluation indicated that the limiting oxygen index value of the treated fabric was increased to 40.0% from 18.2%, the peak of heat release rate was reduced by 63.8%, and the total heat release was reduced by 57.6% compared with that of the control sample. The enhanced flame retardancy was attributed to the excellent charring ability in the condensed phase. The treated fabric also showed anti-sticking, self-cleaning, and oil/water-separating properties. This coating treatment without any F, Cl, Br, P elements involved is regarded as a clean methodology for producing flame retardant and superhydrophobic cotton fabrics. [Display omitted] • The macro-nano rough structure was constructed by phase-separated chitosan. • The coating has no F, Cl, Br, P elements. • The treated cotton fabric with only 5.8 wt% coating was self-extinguishing. [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]

[Display omitted] • A flame retardant (POSB) containing P and B elements was synthesized. • EP/5 wt% POSB had an LOI value of 32.9 % and passed UL-94V-0 rating. • The heat and smoke production of EP were greatly reduced. • The dielectric constant and dielectric loss of EP composite were decreased. This work presents a novel approach to enhance the flame retardancy and dielectric properties of epoxy resin (EP) through the incorporation of a newly developed flame retardant (POSB) containing phosphorus and borate. The EP composite with only 5 wt% POSB achieves an impressive limiting oxygen index (LOI) of 32.9 % and attains a V-0 rating in the UL-94 test. Cone calorimetry results reveal a substantial reduction of 33.3 % in peak heat release rate (pHRR) and 36.7 % in peak smoke production rate (pSPR) for the EP/POSB sample compared to the control EP sample. The impact of POSB on mechanical and dielectric properties is comprehensively analyzed, demonstrating minimal impact on tensile, impact, and flexural performance, as well as transparency in the EP sample. Notably, the EP/5 wt% POSB composite exhibits significantly decreased dielectric constant and dielectric loss in the frequency range of 103 ∼ 106 Hz. This research introduces a strategy of producing materials for electronic products with simultaneous improvements in flame retardancy, dielectric properties, mechanical performance, and transparency. [ABSTRACT FROM AUTHOR]

Various polymer substrates have their particular combustion features, therefore, developing an effective universal flame retardant strategy for various polymer substrates is of great practical importance. Meanwhile, as substitutes for petroleum-based products, bio-based flame retardants and biodegradable polylactic acid (PLA) meet the requirements of sustainable development. In this work, a fully bio-based flame retardant coating (PAGS) was prepared using phytic acid (PA) and guanosine (GS). PAGS was used as a universal flame retardant coatings for polylactic acid (PLA) fabrics and other substrates, including cotton fabrics, polyethylene terephthalate (PET) fabrics, polyamide (PA) fabrics, polyurethane (PU) foams, polyethylene terephthalate (PET) films, and woods. The PAGS-treated substrates were able to self-extinguish and eliminate molten droplets. Similarly, the PAGS coating significantly suppressed the heat release of each substrate. The P-containing free radicals in the gas phase were able to interact with highly reactive H , HO and alkyl radicals, blocking the chain reaction during combustion. The flammable gas density was also diluted by nonflammable gases. The formed continuous porous and dense intumescent char layer hindered heat and oxygen. It is suggested that this work provides a simple and efficient flame retardant strategy for improving the fire safety of various polymer substrates. [Display omitted] • An eco-friendly flame retardant coating (PAGS) was prepared. • The PAGS coating was applied on polylactic acid fabrics and other substrates. • The PAGS coating improved the flame retardancy and eliminated molten dripping. • The intumescent flame retardant mechanism of PAGS was proposed. [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]

• 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]

• A novel DOPO derivative was synthesized and employed as a multi-functional additive for EP. • The EP composite with superior fire-retardancy, mechanical properties and anti-aging performance was obtained. • HP-DOPO shows good compatibility, while accelerate the curing procedure and do not sacrifice the transparency of cured EP. Aiming to develop high performance flame-retardant epoxy resin (EP), a novel phosphorus-containing flame retardant named 6-(3-(2-hydroxyphenyl)propyl)dibenzo-[1,2]oxaphosphinine 6-oxide (HP-DOPO) was synthesized and employed as a multi-functional additive for EP with simultaneously excellent flame retardancy, transmittance, mechanical enhancement and anti-aging. With 5 wt.% loading of HP-DOPO, EP composites showed outstanding flame retardancy with a high limiting oxygen index of 35.6 % and V-0 rating in UL-94 test, while the cone calorimetric test results demonstrated that HP-DOPO could efficiently restrain the heat and smoke release. Compared with pure EP, the resultant EP/5 %HP-DOPO exhibited superior mechanical properties with 27.9 % and 56.2 % increase in tensile and impact strengths, respectively. Furthermore, HP-DOPO accelerated the curing procedure and did not sacrifice the transparency of cured EP, while anti-aging performance was obtained at the same time. The exploration of this novel multi-functional additive provided a powerful basis for the technologies and potential industrial applications of epoxy materials. [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]

[Display omitted] • Bio-based lentinan (LNT) and ammonium phytate (APA) were introduced onto cotton fabric. • The flame retardancy of cotton fabric was significantly enhanced by the presence of APA and LNT. • The LNT outer layer improved the thermostability, durability, and breaking force of the APA-treated cotton fabric. As the most widely used natural fabric, cotton fabric is highly flammable with serious fire hazard concerns. The use of biomass materials to impart flame resistance to fabrics is always a hot topic of interest. In this work, a novel durable flame retardant cotton fabric (Cotton-APA/LNT) was fabricated by successively covalent bonding ammonium phytate (APA) and lentinan (LNT). The Cotton-APA/LNT fabric sample had a highly limiting oxygen index (LOI) value of 51.5 % and was self-extinguished in the vertical burning test (VBT) at 18.0 % weight gain. The peak heat release rate and total heat release values were decreased by 91.5 % and 46.0 %, respectively compared with those of the control cotton. Besides, after 50 laundering cycles (LCs), the fabric was still self-extinguished in the VBT with an LOI value of 34.2 %. APA fully strengthened the role of acid source by the presence of LNT. The constructed LNT outer layer showed comprehensive improvements in thermostability, flame retardancy, smoke suppression, durability, and breaking force. Specifically, the Cotton-APA/LNT sample had a higher LOI value (↑4.3 %), lower total heat release (↓23.8 %), lower total smoke production (↓29.1 %), higher thermostability (↑27 °C under air), better char formation ability (↑2.0 % under air), higher durability (self-extinguished in the VBT after 50 LCs), and higher breaking force (↑32.5 % in the warp direction and ↑33.9 % in the weft direction) compared with those of Cotton-APA sample. This work has proposed an advanced approach for fabricating eco-friendly durable fire-safety cotton fabrics. [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]

[Display omitted] • Novel bio-based nano-flame retardant with core–shell structure (PA-Fe-HBT) are prepared. • PA-Fe-HBT improved the flame retardancy, UV resistance and recyclability of PLA. • The corresponding mechanisms are proposed. Polylactic acid (PLA) is one of the solutions to the white pollution and energy crisis. However, the using performance (such as flame retardant, weather resistance and mechanical properties) and recycling performance limit its wide application. In this work, a bio-based additive (PA-Fe-HBT) with core–shell structure is synthesized by tannins microspheres and phytic acid (PA). By the presence of 3 wt% PA-Fe-HBT, the limited oxygen index is increased to 25.5%, and the sample can pass UL-94 V-0 grade. At the same time, the mechanical properties of the composites remain good. Besides, the ultraviolet aging resistance and ultraviolet protection ability of the composite are significantly improved. The ultraviolet (UV) transmittance of PLA/3%PA-Fe-HBT sample shows a decrease of 99.97% compared with control PLA. More importantly, the chemical recycling of composites is promoted by PA-Fe-HBT in the absence of external heating. After a simple purification, 88% purity of lactic acid is obtained. It is believed that this work proposes an ingenious design strategy to prepare PLA/PA-Fe-HBT composites with flame-retardancy, UV resistance and chemical recycling performances. [ABSTRACT FROM AUTHOR]

The combustion of polyamide 6 (PA6) fabrics releases toxic smoke, which will pollute the environment and threaten human life and health. Herein, a novel eco-friendly flame-retardant coating was constructed and applied to PA6 fabrics. Needle-like β-FeOOH with a high surface area was firstly constructed onto the surface of PA6 fabrics by the hydrolysis of Fe3+, sulfamic acid (SA) was then introduced by a facile dipping and nipping method. The growth of β-FeOOH also endowed the PA6 fabrics with certain hydrophilicity and moisture permeability, resulting in improved comfortability. The limiting oxygen index (LOI) of the prepared PA6/Fe/6SA sample was increased to 27.2% from 18.5% of control PA6 sample, and the damaged length was reduced to only 6.0 cm from 12.0 cm of control PA6 sample. Meanwhile, the melt dripping was also eliminated. The heat release rate and total heat release values of the PA6/Fe/6SA sample were decreased to 318.5 kW/m2 and 17.0 MJ/m2, respectively, compared with those of control PA6 (494.7 kW/m2 and 21.4 MJ/m2). The analysis results indicated that nonflammable gases diluted flammable gases. The observation of char residues demonstrated that the stable char layer was formed, which effectively inhibited the transfer of heat and oxygen. The organic solvent-free coating does not contain any conventional halogens/phosphorus elements, which provides a useful methodology to produce environmentally friendly flame-retardant fabrics. [Display omitted] • An eco-friendly coating containing sulfamic acid (SA) and β-FeOOH was constructed. • The halogens and phosphorus elements were not involved in the organic solvent free coating. • β-FeOOH as a scaffold to provide space for the adsorption of sulfamic acid (SA). • The coated PA6 fabrics displayed excellent flame retardancy without dripping. • The coating increased the hydrophilicity and moisture permeability of PA6 fabrics. [ABSTRACT FROM AUTHOR]

In this work, a fully bio-based multi-functional intumescent flame retardant coating containing ε-polylysine (ε-PL), 5-hydroxymethylfurfural (5-HMF), and phytic acid (PA) was successfully constructed on the polyethylene terephthalate (PET) fabrics via a facile one-pot dip-pad-dry process. The introduction of the coating significantly improved the fire performance of the fabric. The treated PET fabric had a limiting oxygen index value of 28.1 %, and was free of molten drops in the vertical flammable test. The flame retardant mechanism analysis indicated that the three components in flame retardant coating formed intact char layers during combustion which hindered the transfer of oxygen/heat and inhibited the generation of flammable volatiles. The treated PET fabric also exhibited better antibacterial ability against E. coli and S.aureus compared to the control sample. Besides, the breaking strength and the elongation at the break of the treated PET fabric were slightly improved. This work provides a facile and sustainable strategy to fabricate PET fabrics with flame retardancy and anti-dripping properties. [Display omitted] • A fully bio-based flame retardant and antibacterial coating was constructed. • The coated PET fabrics showed self-extinguishing and anti-dripping properties. • The synergistic flame retardant mechanism was evaluated. [ABSTRACT FROM AUTHOR]

The incorporation of flame retardants (FRs) is often applied to reduce the fire risk of flexible polyurethane foam (FPUF), however, the addition of FRs usually brings mechanical loss, and the emigration of FRs during service life results in a decrease in flame retardancy. In this work, a hyperbranched FR (HPNP) containing nitrogen and phosphorous was synthesized via transesterification between dimethyl methyl phosphonate (DMMP) and triethanolamine. The distribution of HNPN in FPUF was simulated by the Materials Studio software. The flammability was characterized by the open flame test, horizontal combustion test, limiting oxygen index (LOI) and cone calorimeter test. The FPUF sample containing only 4 wt% HPNP self-extinguished immediately after the removal of the ignitor. For the FPUF containing 8 wt% HPNP sample, the LOI was increased to 26.3% from 17.9%. The total heat release and total smoke production were reduced by 65% and 75%, respectively compared to that of the control FPUF sample. More importantly, the radical trapping action in the gas phase and the charring promotion in the condensed phase were simulated and verified based on the experimental data. Furthermore, the interfacial energy calculation and molecular dynamics simulation suggested that the improved compatibility of FPUF/HPNP resulted in the superior durability of HPNP in FPUF. In addition, the FPUF samples containing HPNP also showed enhanced mechanical properties. It was expected the hyperbranched HPNP would be an ideal additive to produce flame retardant FPUF with excellent comprehensive performance. [Display omitted] • A hyperbranched flame retardant (HPNP) was synthesized by transesterification. • FPUF containing 8 wt%HPNP showed self-extinguish effect with an LOI of 26.3%. • Total smoke release of FPUF was greatly reduced by the presence of 8 wt% HPNP. • The addition of HPNP also enhanced the mechanical properties of FPUF. • The improved compatibility of HPNP and FPUF suppressed the emigration of HPNP. [ABSTRACT FROM AUTHOR]

The large-scale application of ecofriendly polymeric materials has become a key focus of scientific research with the trend toward sustainable development. Mechanical properties and fire safety are two critical considerations of biopolymers for large-scale applications. Polylactic acid (PLA) is a flammable, melt-drop carrying, and strong but brittle polymer. Hence, it is essential to achieve both flame retardancy and mechanical enhancement to improve safety and broaden its application. This study reviews the recent research on the flame retardant functionalization and mechanical reinforcement of PLA. It classifies PLA according to the type of the flame retardant strategy employed, such as surface-modified fibers, modified nano/micro fillers, small-molecule and macromolecular flame retardants, flame retardants with fibers or polymers, and chain extension or crosslinking with other flame retardants. The functionalization strategies and main parameters of the modified PLA systems are summarized and analyzed. This study summarizes the latest advances in the fields of flame retardancy and mechanical reinforcement of PLA. [Display omitted] • Representative cases on flame retardant and mechanical enhancement of PLA are summarized. • Six categories to enhance flame retardancy and reinforcement of PLA are classified. • The flame-retardant and reinforcing mechanism are extracted. • Suggestions for flame retardant and mechanical reinforced PLA fabrication are presented. [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]

• A flame retardant diphenylphosphinyl vanillin diamino triazole (DPPVA) is synthesized. • The limit oxygen index of EP/4%wt DPPVA is 34.5%, and the sample passes UL-94 V-0. • The mechanical properties of EP/4%wt DPPVA are similar as that of the control EP. • The EP/4%wt DPPVA is transparent, and exhibits repellence to E. coli and S. aureus. A flame retardant DPPVA was synthesized through a Schiff-base reaction of vanillin, 3,5-diamino-1,2,4-triazole, and diphenylphosphinyl chloride, which was used to improve the thermal stability, flame retardancy, and antibacterial activity of the cured epoxy resin (EP). The EP/4% DPPVA sample looked yellow, but it was still transparent, and it passed the V-0 rating with a limit oxygen index (LOI) of 34.5%. The presence of 4wt% DPPVA in EP decreased the peak heat release rate (pHRR), total heat release (THR), and total smoke production (TSP) by 32.5%, 25.2%, and 29.3%, respectively. Compared with that of the control EP, the char residue was increased to 14.9wt% from 9.6wt%. In TGA the max mass loss rate of the EP/4% DPPVA sample was reduced to 0.86%/ °C from 1.75%/ °C of the control sample, which means the pyrolysis of EP was slowed down by DPPVA. The EP/4% DPPVA sample exhibited effective repellence to E. coli and S. aureus. The addition of 4% DPPVA to EP decreased the impact strength to 8.5 kJ/m2 from 9.9 kJ/m2, which was acceptable for many industrial scenarios. This work provided a potential strategy with an easy process for manufacturing flame retardant, antibacterial and transparent EP composites. [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]

Flexible polyurethane foam (FPUF) is widely used in our life, but it is inherent flammable. The demand for environmental-friendly multi-functional FPUF has been increasing rapidly in the last decade. In this work, a novel bio-based flame retardant coating was constructed by chemically reacting sodium alginate (OSA) and polydopamine (PDA) on the FPUF, followed by depositing nanorod-like β-FeOOH molecules through complexation reaction to form a biomimetic structure. The limiting oxygen index of the coated FPUF samples reached 25.5%. The peak heat release rate was reduced by 45.0%, and the smoke density of the coated sample was decreased by 69.1% compared to that of the control FPUF sample. It was proposed that the OSA-PDA-β-FeOOH decomposed during combustion to promote the formation of compact crosslinked char and released inert gases to dilute the combustible gases, and the β-FeOOH transferred to Fe 2 O 3 to settled the smoke particles reducing the smoke release. Furthermore, the coating with shark skin like structure endowed FPUF antibacterial ability because of its good superoleophobicity underwater. This work provided a novel strategy to construct a biomimetic multifunctional coating on the FPUF. [Display omitted] • A biobased coating was constructed on flexible polyurethane foam (FPUF). • The coating with a biomimetic structure improved the flame retardancy of FPUF. • The LOI of the coated FPUF reached 25% after washing and/or abrasion. • The coating decreased the peak smoke density of FPUF by 68.5%. • FPUF with superoleophobicity underwater showed antibacteria for cleaning application. [ABSTRACT FROM AUTHOR]

• The flame retardancy and thermal degradation behavior of iPP and sPP has been investigated. • IPP can achieve better flame retardancy with the equal amounts of IFR compared with sPP. • The reason for the difference of iPP and sPP in flame retardancy was discussed through viscosity, melt point, crystallization and thermal degradation. This work investigated the difference in flame retardancy and degradation behavior of polypropylene (PP) composites with different configurations. The piperazine pyrophosphate (PAPP) was combined with melamine polyphosphate (MPP) to construct an intumescent flame retardant system, before incorporating into the PP system by melt blending. It showed that by the introduction of equal amounts of flame retardant, isotactic polypropylene composites (iPP-IFR) can achieve better flame retardancy with a desirable UL-94 V-0 rating, whereas syndiotactic polypropylene (sPP-IFR) shows poor fire performance. Melt index tests show that sPP-IFR sample is easy to flow and prone to melt drops. Differential scanning calorimetry results show that iPP-IFR has a higher degree of crystallinity. The thermogravimetric infrared coupling results show that sPP-IFR produces more small molecule hydrocarbon gases during combustion, making the system more difficult to achieve satisfied flame retardancy. The burning properties of iPP-IFR have been proven to be somewhat better compared to that of sPP-IFR, and sPP is more difficult for flame retardant modification. [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]

A strategy to achieve flame retardancy, smoke suppression, and filtering capability simultaneously for the cotton fabrics was proposed. The cotton fabric sample was firstly treated with a polydopamine (PDA) solution through a dip-nip process, then the layered double hydroxides (LDH) were vertically introduced on the fabric surface before depositing Fe3+ chelated with phytic acid (PA). The obtained Cotton-PDA-LDH-Fe3+PA sample exhibited excellent flame retardancy and smoke suppression. The limiting oxygen index of the treated cotton sample reached 33.9%. For the Cotton-PDA-LDH-Fe3+PA sample, the total heat release was dropped to only 1.9 MJ/m2 from 8.7 MJ/m2 of the control cotton fabric sample, and the total smoke production was decreased from 138.9 m2/m2 to 68.1 m2/m2. The Cotton-PDA-LDH-Fe3+PA sample showed excellent ability of filtering particulate matter with a filtration efficiency of 91%. It is expected that this work provides a useful method to produce superior multi-functional cotton fabrics [Display omitted] • Cotton fabric achieves flame retardant, smoke suppression and PMs filter by a compound coating. • Phytic acid/polydopamine is efficient and bio-safe synergistic flame retardants of cotton fabric. • Directionally-grew layered double hydroxides on cotton fabric suppress smoke in burning. • The chelated Fe3+ ions work with LDHs together to capture PMs durably. [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]

• Poly-siloxane encapsulated EG (Si@EG) was prepared and introduced into PP composites. • The Si@EG significantly improved flame retardancy of PP composites. • Finite element analysis was used to evaluate burning behavior of PP composites. Expandable graphite (EG) was encapsulated by a poly-siloxane (Si@EG) and introduced into polypropylene (PP) composite as flame retardant additives. Compared with that of PP/EG composite, PP/Si@EG composite achieved the V-0 rating with a loading of 25 wt.%. Additionally, the total heat release of PP/Si@EG composite was decreased by 42% compared with that of control PP in the cone calorimeter test. To investigate the burning behavior of PP/Si@EG, a burning rate measurement was designed and finite element analysis was introduced to evaluate influences brought by char volume and shape formed by EG. The temperature field was calculated among EG and Si@EG expanding in the PP matrix. Additionally, Fourier transforms infrared spectroscopy and scanning electron microscope observation were operated to investigate the char residues. It was proposed that the outstanding flame retardancy brought by Si@EG was owing to the compact and dense char. [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]

An integrated multi-functional additive was fabricated by successively grafting melamine (MEL) and phytic acid (PhA) on multiwalled carbon-nanotubes (MWNCTs), and was then applied in PA6 to improve the flame retardancy and light aging resistance of the composite. The limit oxygen index of PA6 composite containing 7 wt% PhA-MEL-MWCNTs was increased to 26.4 from 21.0. The smoke and CO release were significantly reduced by 48% and 88% respectively, and the severe melt dripping of PA6 in burning was eliminated. It is proved that PhA-MEL-MWCNTs can absorb ultraviolet (UV) radiation, and hence significantly reduces the mechanical property loss of the PA6 composite after UV aging. The tensile strength of the aged PA6/7 wt%PhA-MEL-MWCNTs composite sample only decreased by 18.1%, which was significantly lower than the loss rate of the control aged PA6 sample (62.5%). This protocol provides a new opportunity for fabricating long-life flame retardant polyamide composites. [Display omitted] • PhA-MEL-MWCNTs was fabricated by grafting melamine and phytic acid on MWCNTs. • PhA-MEL-MWCNTs improved flame retardancy and light aging resistance of PA6. • The melt dripping of PA6 was eliminated by 7% PhA-MEL-MWCNTs. • The mechanical loss of PA6 after UV aging was reduced by PhA-MEL-MWCNTs. • The potential danger of PA6 in dairy usage was reduced. [ABSTRACT FROM AUTHOR]