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Herein, piperazine phosphoramide derivatives (PPDO) and titanium carbide modified by hexadecyl trimethyl ammonium bromide (c-Ti3C2) were blended with epoxy resin (EP) to fabricate EP/c-Ti3C2/PPDO nanocomposites. According to thermogravimetric analyzer (TGA) results and pyrolysis kinetic analysis, EP/c-Ti3C2/PPDO nanocomposites can improve the thermal stability and the activation energy of EP. Furthermore, thermal degradation mechanism of EP and its nanocomposites with conversion between 0.55 and 0.99 conforms to the F3 model. With 1 wt% c-Ti3C2 and 3 wt% PPDO incorporated, the LOI value of EP/c-Ti3C2-1/PPDO-3 can reach up to 32% while achieves V-0 rating in the UL-94 test. Based on the cone calorimeter results, the peak heat release rate of EP/c-Ti3C2-1/PPDO-3 reduced by 40.1%. More continuous and dense phosphorus-rich char residues were produced for EP/c-Ti3C2-1/PPDO-3 nanocomposites, which can act as a physical barrier to hinder the heat transfer, protect the underlying polymers from further decomposition and isolate the diffusion of combustible gases. The synergistic effect between c-Ti3C2 and PPDO in catalytic carbonization obviously accounts for the improved flame retardant performance. This work provides an insight into the flame retardant mechanism and the thermal degradation mechanism of c-Ti3C2 and PPDO on EP, showing a promising application potential of c-Ti3C2 and PPDO in enhancing the thermal stability and flame retardancy of EP. [ABSTRACT FROM AUTHOR]

Polymer composites exhibiting exceptional characteristics, including high thermal conductivity, thermal stability, mechanical strength, and flame resistance, offer significant potential for contemporary electronic applications. Their appeal is further heightened by features such as straightforward manufacturing processes, cost-effectiveness, and consistent physical and chemical properties. In this study, a bio-derived ligand was synthesized from vanillin through a Schiff base reaction. Subsequently, this ligand was employed in the synthesis of a silver complex (Ag-complex) through a Schiff base ligand-mediated process designed to extract silver ions from a wastewater stream. Moreover, the Ag-complex served as an additive to enhance the flame resistance and amplify the thermal conductivity of an epoxy resin (EP). The results from thermogravimetric analysis (TGA) revealed that the Ag-complex promoted the formation of char in the EP composites. Specifically, the EP composite containing 20.0 wt% of the Ag-complex exhibited a significantly increased limiting oxygen index (LOI) of 27.0%, and demonstrated improved thermal conductivity. Additionally, this composite showed a substantial reduction (47.84%) in heat release rate (HRR), a noteworthy decrease of 45.16% in total heat release (THR), and a marked decline in smoke production rate (SPR) by 26.15%, along with reductions in CO production rate (52.34%) and CO 2 production rate (29.53%). Furthermore, the EP composite containing 20.0 wt% of the Ag-complex displayed superior tensile strength compared to the unmodified EP. This research introduces an innovative approach for developing fire-resistant EP with enhanced thermal conductivity, achieved by repurposing waste materials derived from water decontamination adsorbents. • A Schiff base ligand derived from vanillin was produced. • An Ag-complex was formulated by extracting silver ions from wastewater using the Schiff base ligand. • The HRR of the EP-Ag-complex-20wt% decreased by 47.8% when compared to that of the pristine EP. • The SPR of the EP-Ag-complex-20wt% decreased by 26.1% in comparison to that of the pristine EP. • The addition of 20wt% of the Ag-complex significantly enhanced the thermal conductivity of the EP composite. [ABSTRACT FROM AUTHOR]

As one of the most used polyurethane, flexible polyurethane foam (FPUF) still confronted highly flammable problems. However, current flame retardant employed in FPUF deteriorated the other utilization performances, such as mechanical properties. In this work, cerium stannate decorated graphene nanosheets (GNS@Ce2Sn2O7, GCSO) was prepared to fabricate flame retardant FPUF composites. Compared to pure FPUF, the tensile strength and average compression strength of FPUF composites accomplished 100 and 412% increase, respectively, while the average rebound was basically maintained. In contrast to pure FPUF, total heat release and total smoke production of FPUF composites displayed a 42.2 and 75.1% reduction, respectively. Furthermore, the released toxic gases (such as, CO2, CO and NOx) during combustion were greatly decreased. These results were due to the catalytic and barrier effect of GCSO promoting the formation a high‐quality char residue with a compact, intact and dense morphology. Therefore, it provides a facile method to fabricate FPUF composites with advanced comprehensive performance for the furniture field. [ABSTRACT FROM AUTHOR]

Flexible polyurethane foam (FPUF) is extremely flammable and will release a large number of toxic fumes during the combustion process, which brings great safety hazards. Therefore, a binary hybrid nanocoating composed of graphene oxide (GO) and octaamino polyhedral oligomeric silsesquioxane (OA‐POSS) is deposited on the surface of FPUF through layer‐by‐layer self‐assembly technology, with the aim of enhance the flame retardancy and smoke suppression properties of the hybrid FPUF. Compared with pure FPUF, the peak heat release rate, the total heat release, the peak smoke production rate and the total smoke release of FPUF@GO/OA‐POSS‐6 is decreased by 67.3%, 28.3%, 65.03% and 42.9%, indicating the hybrid FPUF excellent flame retardancy and smoke suppression properties. Compared with pure FPUF, the tensile strength of FPUF@GO/OA‐POSS‐6 is increased by 42%, and after three times of compression, the compressive strength increases by 83.17% on average. Facts have proved that the hybrid effect between GO and OA‐POSS enhances the flame retardancy, smoke suppressive effects, tensile strength and compressive strength of FPUF. [ABSTRACT FROM AUTHOR]

• Multi-elemental based flame retardant treatment was done for PA66 textiles • The flame retardancy and thermal stability were escalated in a several fold • P, N and Si elements based coating improved the LOI value by 25.5 % • A reduction by 34 % in pHRR was achieved from P, N, Si and B elements • A minimal add on % can surely impart total fire retardancy to PA66 textiles Multi-elements based hybrid (i.e., organic/inorganic) flame retardant compounds, namely phenyl dichlorophosphate (PDP) based two different engineered structures synthesized with (3-Aminopropyl) triethoxysilane (APTES) (i.e., containing P, N and Si) and boric acid-doped-APTES (BA-d-APTES) (i.e., containing P, N, Si and B) were considered in escalating the fire performance of polyamide 66 (PA66) textiles. All the treated fabrics irrespective of type and loading % (i.e., 5–10 wt. %) of flame retardant compounds exhibited better thermal stability at a higher temperature range and produced enhanced charring. In line, such treatment increased the limiting oxygen index (LOI) value by up to 25.5 % for the fabric sample modified with 10 wt. % of PDP-APTES (i.e., PA66-PDP-A-10W). Moreover, the applied finishing diminished the serious dripping of PA66 textiles completely and brought a significant reduction in the peak heat release rate (pHRR) by 34 % along with a slight reduction in the total heat release rate (THR) by about 5 %. Even more, such treatment left a negligible impact of mechanical properties of treated textiles while offered a considerable durability against home laundering. Thus, these multi-elemental based hybrid compounds optimized in the condensed phase mechanism were found to be an effective flame retardant for PA66 textiles. Image, graphical abstract [ABSTRACT FROM AUTHOR]

• TiO 2 /SiO 2 NPs based multifunctional coatings were prepared for PA66 textiles • The flame retardancy and hydrophilicity were escalated in a several fold • The TiO 2 nanoparticle along with phytic acid improved the LOI value by 24.5% • TiO 2, phytic acid and chitosan handed a substantial reduction in pHRR by 25% • SiO 2 nanoparticle and phytic acid formulation enhanced hydrophilicity markedly Novel nanoparticles (NPs) namely, TiO 2 and SiO 2 along with naturally derived phytic acid (PA) and chitosan (CS) were used to improve the flame retardant and hydrophilic properties of polyamide 66 (PA66) fabrics via pad-dry-cure technique. The application of PA-TiO 2 enhanced the limiting oxygen index (LOI) value up to 24.5 % for the treated fabrics from 19.5% of the pure fabric and accelerated char yield%. Conversely, the introduction of chitosan (CS) into the PA-TiO 2 /SiO 2 formulations brought a significant reduction in the peak heat release rate (pHRR) where a maximum reduction of 25 % was achieved for the PA66-PA-CS-T fabric sample. Meanwhile, the hydrophilicity of treated fabrics was improved significantly, especially with PA-SiO 2 formulation as the water contact angle was reduced to 29˚ for the treated fabrics from 112˚ for the pure PA66. In addition, the formulations containing nanoparticles (TiO 2 /SiO 2) along with PA boosted up the tensile strength of treated textiles. [ABSTRACT FROM AUTHOR]

In the present work, lanthanum phenylphosphonate (LaPP)–based multilayered film was fabricated on the surface of flexible polyurethane (PU) foam by layer‐by‐layer self‐assembled method. The successful deposition of the coating was confirmed by scanning electron microscopy (SEM) and energy‐dispersive X‐ray (EDX). Subsequently, the thermal decomposition and burning behavior of untreated and treated PU foams were investigated by thermogravimetric analysis (TGA) and cone calorimeter, respectively. The TGA results indicated that Tmax2 of treated PU foams were increased by approximately 15°C to 20°C as compared with untreated PU foam. The peak heat release rate (PHRR) and total heat release (THR) of PU‐6 (with 19.5 wt% weight gain) were 188 kW/m2 and 20.3 MJ/m2, with reductions of 70% and 15% as compared with those of untreated PU foam, respectively. Meanwhile, the smoke production of treated PU foam was suppressed after the construction of LaPP‐based coating. [ABSTRACT FROM AUTHOR]

Carbon black microencapsulated ammonium polyphosphate (APP@CB) was synthesized to enhance the interfacial compatibility, mechanical property and flame retardancy of polyurethane (TPU). The chemical structure of APP@CB hybrids were characterized by Raman spectra and scanning electron microscope. Compared with APP flame retardant TPU composite, the tensile strength of TPU composite containing APP@2CB increased by 23%, and the smoke density approximately decreased by 46%. This is owing to the strong interaction between the CB and TPU in TPU4 (flame retardant by APP@2CB) composite. Furthermore, the TPU4 composite restrained the smoke and toxic volatiles evolved, indicating suppressed toxicity of the TPU composites. [ABSTRACT FROM AUTHOR]

Graphene‐polyaniline/nickel hydroxide ternary hybrid (RGO‐PANI/Ni(OH)2) was synthesized and incorporated into epoxy resin (EP) to improve the fire retardant property. Thermogravimetric analysis results showed that the RGO‐PANI/Ni(OH)2 nanohybrid could catalyze the thermal degradation of epoxy matrix that was essential to trigger the char formation. The char yield of the RGO‐PANI/Ni(OH)2/EP composite was improved compared with that of the samples with graphene and polyaniline only. With 3.0‐wt% RGO‐PANI/Ni(OH)2, significant reduction in peak heat release rate (40%) and peak smoke production rate (36%) was observed in the cone calorimeter tests. Thermogravimetric analysis/infrared spectrometry (TG‐IR) results indicated that the flammable volatiles of the RGO‐PANI/Ni(OH)2/EP composite was reduced compared with those of the EP and RGO‐PANI/EP. The superior flame retardant and smoke suppressant behaviors of the RGO‐PANI/Ni(OH)2 nanohybrid over RGO‐PANI were attributed to the combination of good barrier effect of graphene with catalytic ability of char formation of PANI and metal hydroxide. [ABSTRACT FROM AUTHOR]

In this work, two kinds of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO)-based phosphonamidate flame retardants named 4,4′-diamino-diphenyl methane (DDM)-DOPO and morpholine (MPL)-DOPO are successfully synthesized by the classic Atherton–Todd reaction, and their chemical structures are characterized by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). Epoxy composites containing DDM-DOPO or MPL-DOPO are prepared, which still retain relatively high transparency compared with pure epoxy resin (EP). Its fire behavior is studied in terms of vertical burning test (UL-94), limiting oxygen index (LOI), and cone calorimeter tests. The LOI values can achieve 30% and UL-94 test past V-0 rating for DDM-DOPO-modified epoxy composites with 0.25 wt% phosphorus content. The cone calorimeter results indicate that the modified epoxy composites can release less heat and smoke compared with pure EP. Also, thermal degradation behavior and flame-retardant mechanism of epoxy composites are investigated by thermogravimetric analysis and thermogravimetric analysis/infrared spectrometry. The results indicate that two DOPO-based phosphonamidates show a significant gaseous-phase effect on reducing the release of combustible volatiles. [ABSTRACT FROM AUTHOR]

Building energy consumption is an important component in the total social energy consumption. How to reduce building energy consumption became an important issue in today's society. Therefore, building insulation materials, as a kind of effective energy saving method, has been widely used for the external walls. However, the occurrence of many building fires caused by the ignition of the flammable insulation materials has brought serious damage to people. Consequently, it is significant to develop insulation materials which possess high level of fire safety. The aim of this study was to develop high efficient phosphorus‐based flame‐retardant system for polyisocyanurate‐polyurethane (PIR‐PUR) foam. Ammonium polyphosphate (APP) was used as condensed phase flame retardant and dimethyl methylphosphonate (DMMP) were used as gas phase flame retardant for preparing flame‐retardant PIR‐PUR foam. The flame retardancy, thermal decomposition, and combustion behaviors of PIR‐PUR foams were evaluated by limiting oxygen index (LOI) test, vertical burning test, thermogravimetric analysis, cone calorimeter test (Cone), and microscale combustion calorimeter test, respectively. The LOI results showed that the PIR‐PUR sample simultaneously containing APP and DMMP possessed higher flame retardant efficiency, which indicated that APP and DMMP possessed synergistic flame‐retardant effect in PIR‐PUR foam. Cone results indicated that the presence of DMMP can delay the ignition of specimen and delay the time to reach the maximal peak heat release rate. Moreover, the mechanical performance and thermal insulating properties were evaluated, respectively. [ABSTRACT FROM AUTHOR]

In this study, we finished cotton fabrics with polyethylenimine (PEI)/melamine and phytic acid (PA) by layer-by-layer assembly to enhance their flame retardant properties. Subsequently, the flame retardant treated cotton fabrics were impregnated with a diluted solution of poly(dimethylsiloxane) (PDMS) for improving water repellent behavior. The morphology and chemical composition of un-treated and treated cotton fabrics were measured by scanning electron microscopy equipped with Energy Dispersive X-ray analysis. Thermogravimetric analysis indicated that the addition of melamine/PEI-PA coating induced earlier degradation of cotton fabrics to form char, and the presence of PDMS further improved the char yield. The flame retardant property was significantly enhanced as evidenced by the self-extinguishing behavior of Cotton-4BL and Cotton-4BL-PDMS fabrics in the vertical burning tests. The peak heat release rates of the treated cotton fabrics were decreased by more than 50% in contrast to that of the original cotton. The significant improvement in flame retardancy was attributed to the catalytic effect of the melamine/PEI-PA coating on char formation and the char stabilization effect of PDMS. The char layer with good thermal resistance played a crucial role in suppressing flame spread. The Cotton-4BL-PDMS fabrics also exhibited good water repellent behavior, which displayed an initial contact angle larger than 130° and almost unchanged over time. [ABSTRACT FROM AUTHOR]

Polystyrene (PS) composites with different loading level and proportions of CNAPP20 [i.e., ammonium polyphosphate (APP) wrapped graphitic carbon nitride (g-C3N4), where mass ratio of g-C3N4 to the CNAPP was 20%] to aluminim phosphinates were fabricated. The results indicated that the additives had good interfacial interaction with PS matrix. It is noted that only the PS-1 achieved the UL-94 V-0 rating, and value of limited oxygen index was also the highest among all the composites. The peak of heat release rate (pHRR) and total heat release of all the composites were greatly reduced as compared to those of virgin PS (77.5% decrease in pHRR for PS-1). Combining CNAPP20 with DAHPi (i.e., aluminim diethylphosphinate) induced the formation of a cohesive and uniform carbonaceous residue. In addition, the concentration of carbon dioxide, smoke and carbon monoxide was reduced upon incorporation of CNAPP20 and DAHPi. The property improvements were attributed to the explanations that the formed continuous and dense char residues acted as protecting layers to prevent the heat and mass permeation, and that the evolved gas diluted the oxygen, which retarded the further combustion of flammable compounds. Also, the generated free-radical scavengers retarded polymeric chain breakage. [ABSTRACT FROM AUTHOR]

The exploration of green flame retardants is of great significance for fire safety, ecological environment protection, and resource saving. Herein, a novel phosphorus containing chitosan‐cobalt complex (CS‐P‐Co) was successfully synthesized for the first time and then introduced into polylactic acid matrix. Owning to the formation of cobalt salts, the CS‐P‐Co exhibits good thermal stability and catalytic char effect. The as‐fabricated biodegradable polylactic acid/CS‐P‐Co composites with small amounts of CS‐P‐Co (≤ 4.0 wt%) show remarkably improved flame retardancy, such as decreased peak heat release rate and total heat release by 23.0% and 20.0%, respectively. Scanning electron microscopy, Thermogravimetric analysis, and Raman results demonstrate that compact graphitized char layers are formed on the composite surface during combustion, attributed to the catalytic effect of CS‐P‐Co. The char inhibits diffusion of heat, mass, and oxygen, which plays a key role in the flame retardancy enhancement. [ABSTRACT FROM AUTHOR]

Molybdenum trioxide (MoO3) microrods, nanofibers, and nanoplates were synthesized via the hydrothermal method and high-temperature calcination method, respectively. Then the MoO3 was added into polyurethane elastomer, respectively. The flame retardancy and smoke suppression of the composites added with different MoO3 were studied by thermal gravimetric analysis, cone calorimeter, and smoke density. The results show that the three kinds of MoO3 with different morphologies could promote the formation of char and possess flame retardancy and smoke suppression, and MoO3 nanofibers exhibit a higher degree of flame retardancy, and 1 wt% addition could make the peak heat release rate of polyurethane elastomer composites reduce from 881.6 kW m−2 for a pure sample to 343.4 kW m−2, a decrease by 61.0%. As for smoke suppression, MoO3 nanoplates possess the best smoke suppression; 5 wt% could decrease a pure sample's smoke density by 41.3% from 361 to 212. Moreover, the char residue of composites after combustion was analyzed by Raman spectra and X-ray photoelectron spectroscopy, and the flame retardancy and smoke suppression mechanisms of MoO3 were discussed. [ABSTRACT FROM AUTHOR]

A novel phosphorus-containing monomer, (6-oxido-6H-dibenzo[c,e][1,2]oxaphosphinin-6-yl)methyl acrylate (DOPO-AA), is first synthesized and characterized by Fourier transform infrared spectra (FTIR), 1H nuclear magnetic resonance (NMR) and 31P NMR. The monomer is then introduced into poly (methyl methacrylate) (PMMA) matrix via in situ copolymerization to produce a new PMMA based copolymer (PMMA/DOPO-AA). From UV-vis spectra, microscale combustion calorimeter (MCC) and thermogravimetric analyses (TGA) results, the as-fabricated PMMA/DOPO-AA copolymers not only keep relatively high transparency, but also exhibit remarkable improvements in the flame retardancy and thermal stability, such as increased T0.5 by 60.2°C and limited oxygen index (LOI) by 4.1, and decreased peak heat released rate (PHRR) by 34.7%. Thermal degradation behaviors investigated by real time Fourier transform infrared spectra (RTIR), char structure analysis studied by scanning electron microscope (SEM) and pyrolysis gaseous products studied by TGA coupled with FTIR (TGA-FTIR) demonstrate that the catalytic charring function of DOPO-AA in condensed phase and DOPO flame retardant systems in the gas phase are two key factors for the property enhancements. This work not only provides a promising flame-retardant monomer for polymers, but also will stimulate more efforts on the development of DOPO-containing flame-retardant monomers. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The objective of the present study is to develop a renewable and environmentally benign technique to improve the flame retardancy of cotton fabrics by the layer-by-layer deposition of semi-biobased substances onto the surface of cotton fabrics. The used semi-biobased substances included negatively charged ingredients: phosphorylated poly (vinyl alcohol) (PPVA) and positively charged ingredients: chitosan. Some typical combustion tests, including vertical flame tests and microscale combustion calorimeter were mainly used to measure the fire safety of coated cotton fabrics. The cotton fabric assembled with 30 bilayers can extinguish flame in the vertical flame test. The reduction in peak heat release rate and total heat release could be observed for all coated cotton fabrics compared with that of pure cotton fabrics. Additionally, the thermal stability of cotton fabrics was also discussed by thermogravimetric analysis. The result indicated that thermal stability of coated cotton fabrics were enhanced in the high temperature range (400–700 ∘C). [ABSTRACT FROM AUTHOR]

The main aim of this work was to investigate the synergistic effect of expandable graphite (EG) and aluminum hypophosphite (AHP) on the flame retardancy of rigid polyurethane foams (RPUFs). A series of flame retardant RPUF containing EG and AHP were prepared by one-shot and free-rise method. The flame retardant, thermal degradation, and combustion properties of RPUF hybrids were characterized through limiting oxygen index (LOI) test, vertical burning (UL-94) test, thermogravimetric analysis and microscale combustion calorimeter. The LOI and UL-94 results showed that the RPUF sample with 10wt% EG and 5 wt%AHP passed UL-94V-0 rating and reached a relatively high LOI value of 28.5%, which is superior over other EG/AHP ratios in RPUF at the equivalent filler loading. Microscale combustion calorimeter results revealed that the incorporation of EG and AHP into RPUF reduced the peak heat release rate and total heat release, thus decrease the fire risk of RPUF significantly. Incorporation of EG and AHP improved the thermal stability of RPUF as observed from the thermogravimetric analysis results and also enhanced the thermal resistance of char layer at high temperature from scanning electron microscopy and Raman spectroscopy. Moreover, it could be seen from thermogravimetric analysis/infrared spectrometry spectra that the addition of EG and AHP significantly decreased the combustible gaseous products such as hydrocarbons and ethers. Finally, the synergistic mechanismin flame retardancy was discussed and speculated. [ABSTRACT FROM AUTHOR]

Eco-friendly thermally insulating cellulose aerogels made from environmentally friendly resources are very attractive in materials chemistry, but the high flammability limits their application. Herein, a novel phosphorus-containing flame retardant modifying agent (DOPO-IA) was incorporated into the cellulose nanofiber aerogel and the cellulose composite aerogels were prepared by esterification and followed by a freeze-drying process. The thermal conductivity of the resultant cellulose composite aerogels was in the range of 28.6–31.2 mW/(mK). Meanwhile, the cellulose aerogels modified with DOPO-IA showed significantly enhanced thermal stability, mechanical property, and flame retardant performance compared with the pure cellulose aerogel. The CNF-DI-3 showed a high char residue (19.8 wt%) at 700 °C, which was 187% higher than CNF. Specifically, CNF-DI-3 exhibited remarkable reductions in its PHRR and THR values which were 67% and 60%, respectively, as compared to those of CNF. In summary, it is of significance to synthesize mechanically robust and flame-retardant cellulose aerogels. [Display omitted] [ABSTRACT FROM AUTHOR]

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

In this work, layered aluminum phosphonate (OAHPi) was simply synthesized by one-step and firstly incorporated into PS to enhance fire safety. Thermostability and flame retardancy of composites were investigated. The thermostability and char yield of PS were improved with relatively low additive content (0.5 wt%), confirmed the high-efficiency flame retardant of OAHPi. The value of peak heat release rate was decreased by 39.8% with 5 wt% OAHPi, which indicated that OAHPi had a significant effect on the flame retardancy of PS matrix, which was beneficial to decrease potential fire risk of PS. Homogeneous dispersed nanosheets functioned as physical barrier to hinder the transition of heat and decomposition products. Furthermore, with the coefficient effect of phosphorous-containing compounds, the high-efficiency flame retardancy was acquired. The possible flame-retardant mechanism was also proposed according to experiment results. [ABSTRACT FROM AUTHOR]

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

[Display omitted] • A flame-retardant and photo-thermal microstructure is synthesized. • Thermochromic materials and bio-based flame retardants are used as core and shell. • Heat release and smoke production are effectively suppressed. • The melting and slide of ice block is accelerated by solar-thermal conversion. Due to the extreme dynamic weather, important industrial facilities and infrastructure providing vital support for people's lives usually face the hazards of fire and icing, especially in the weather of thunderstorm and ice. Therefore, to further establish a safe community, we develop a dual-functional polyurea (PUA) coating used as protective materials by introducing flame retardancy and solar de-icing performance. Based on the microencapsulation and electrostatic self-assembly technologies, flame-retardant and thermochromic microcapsules (TCM) are firstly prepared and then added into PUA resin, by using melamine resin and bio-based phytic acid/chitosan (PA/CS) hybrids as double-shell materials. The high phosphorus content of PA and the carbon-forming effect of CS together play a synergistic flame retardant effect, not only improving the thermal stability of microcapsules but also enhancing the flame retardant property of PUA coating. In the cone calorimetry test, the ignition time of TCM@PA/CS@PUA-3 is longer, and the pHRR is reduced by 19.93 %, which shows the improvement of flame retardant performance. Due to the thermochromic mechanism, TCM@PA/CS@PUA composite coatings are able to adjust the photo-thermal conversion ability according to different environment temperature, achieving less temperature in hot environment and higher temperature in cold environment. The excellent photo-thermal conversion ability also promotes the ice melting and slide in 525 s. This polyurea composite coating with both flame retardant and de-icing properties shows great potential for maintaining the normal operation and safety of outdoor industrials and infrastructure in extremely dynamic weather conditions. [ABSTRACT FROM AUTHOR]

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

[Display omitted] In order to meet the rapidly growing demand of multi-functional fabric, a super-hydrophobic flame retardant coating for cotton fabric with superior washability and abrasion resistance was prepared. Flame retardant finishing agent P, P-diphenyl-N-(3-(trithoxysilyl) propyl) phospinic amide (DPTES) and hydrophobic finishing agent polydimethylsiloxane @silicon dioxide (PDMS@SiO 2) were fixed on the surface of cotton fabric by a simple sol–gel technology in combination with convenient brush-coating process. The coated cotton fabric was capable of self-extinguishing a flame, and the Limiting Oxygen Index (LOI) increased from 18.0% for the control cotton fabric to 26.0% for the treated one at weight gain of 30.3%. The water contact angle (WCA) of C3-PDMS-silica is around 154°, and the slip angle is 8°. In addition, the treated cotton fabric exhibits anti-washing and self-cleaning ability due to the superhydrophobic feature and superior friction resistance. The C3-PDMS-silica sample with excellent char-forming ability, as shown by thermogravimetric analysis (TGA), leading to outstanding flame retardancy. A composite char layer was constituted with char residues and ceramic layer during the combustion of inorganic silicon, which plays the role of heat insulation and flame retardant. [ABSTRACT FROM AUTHOR]

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

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

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

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

Incorporating flame retardant fillers is the most efficient way to improve the fire resistance of polylactide (PLA). However, most flame retardant fillers result in deterioration of the mechanical property of PLA so far. Therefore, to create high-performance PLA materials combining excellent flame retardancy with superior mechanical properties remains highly attractive and challenging. In this study, a novel isosorbide-derived poly(phosphoester) (PIDI) was synthesized and used as a bio-based flame-retardant for PLA. The addition of PIDI showed a marginal effect on the change of the glass transition temperature of the PLA composites, but the crystallinity degree of the PLA composites was improved by the inclusion of PIDI. Benefitting from the improved crystallinity, the tensile strength, flexural strength, and impact strength of PLA composite containing 15 ​wt% PIDI was enhanced by 19.4%, 14.1%, and 36.9%, respectively, compared to the virgin PLA. With the addition of 20 ​wt% PIDI, the PLA composite showed an LOI value of 25.5% and a UL-94 V-0 rating in the vertical burning test. The flame retardant effect of PIDI was also demonstrated by a notable reduction (−46%) in the peak heat release rate (PHRR) of PLA composite containing 20 ​wt% PIDI. Such a renewable isosorbide-derived poly(phosphoester) is one of the promising candidates for PLA bio-composites with an outstanding balance between flame retardancy and intrinsic physical properties. [Display omitted] • A novel bio-based poly(phosphoester) (PIDI) was synthesized from isosorbide for flame-retardant PLA. • The crystallinity degree of PLA was improved by the inclusion of PIDI. • A notable reduction (−46%) in PHRR and UL-94 V-0 were observed for PLA composite. • Simultaneous improvement in flame-retardancy and mechanical property of PLA by PIDI was achieved. [ABSTRACT FROM AUTHOR]

Considerable toxic gases and high temperature smoke will be generated during the combustion of polystyrene (PS), which restricts its application. Here, a cobalt-based MOF-71-NH 2 (hereinafter referred to as MOF-NH 2) has been synthesized and further modified with phosphonitrilic chloride trimer (PCT) by a post-synthesis modification (PSM) strategy, named as PCT@MOF-NH 2 , which was used to enhance the flame retardancy of PS. Desirable results were obtained as expected: the fire safety and tensile strength of PS were prominently improved after adding PCT@MOF-NH 2. Compared with pure PS, there were more than 40% and 31% decreases in the value of pHRR and THR with 3.0 wt% content of PCT@MOF-NH 2. From the analysis of gaseous and condensed products after combustion, the possible flame retardancy mechanism of PS nanocomposites can be attributed to the barrier effect of PCT@MOF-NH 2 , which provides a promising application field of MOFs to improve flame retardation of polymer materials. [ABSTRACT FROM AUTHOR]

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

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

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

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

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

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

In this study, polyethylene terephthalate (PET) fabrics were firstly grafted with acrylamide (AM) to ease the fabrics' melt-dripping during the combustion. Then the PET fabrics were treated with layer-by-layer self-assembled coating composed of polyethyleneimine (PEI) and oxide sodium alginate (OSA) together with subsequent cross-linking of hypophosphorous acid (HA). As characterized by attenuated total reflection Fourier transform infrared, X-ray photoelectron spectroscopy and scanning electron microscope, the prepared coating were successfully constructed on the surface of PET fiber. Thermogravimetric analysis indicated that the thermal decomposition of HA cross-linked coating treated PET fabric was clearly retarded as compared with the untreated sample, as reflected on the improvements of temperature of the maximum decomposition rate and char residue. The combination of AM grafting and 15 bilayers HA cross-linked OSA/PEI coating resulted PET-UV-15 fabric self-extinguished the fire without melt-dripping in the horizontal burning test. Meanwhile, PET-UV-15 fabric was durable to 12 laundering cycles. Compared with the untreated PET fabric, 44.0% and 29.4% reductions in the PHRR and THR were achieved for P-UV-15 fabric, respectively. • Durable flame retardant coating was fabricated on the surface of PET fabric. • Thermal stability of treated PET fabric was enhanced by the prepared coating. • The flammability of treated PET fabric was reduced obviously as compared with pure one. • The flame retardant coating was durable to 12 laundering cycles. [ABSTRACT FROM AUTHOR]

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