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

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]

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]

Cellulose as a bio-based material has attracted increasing attention due to its excellent properties. However, cellulose is very flammable and it is necessary to impart flame retardancy to cellulose nanofiber (CNF) foams. In this work, phytic acid (PA)-guanazole (GZ)-CNF composite foams were prepared by a simple freeze-drying method. SEM images indicated that the resultant PA-GZ-CNF composite foams exhibited a hierarchical porous structure. Moreover, the introduction of PA and GZ slightly affected the thermal conducting property of CNF foams. PA-GZ-CNF composite foams possessed excellent flame retardancy with a much higher LOI value and a UL-94 V-0 rating compared to that of pure CNF foams. Moreover, the peak of the heat release rate of PA-GZ-CNF composite foams exhibited a significant decrease from 57.80 to 29.27 kW/m2 and the total heat release declined from 2.10 to 1.21 MJ/m2. PA-GZ-CNF composite foams formed a protective char layer covered on the surface, which produced less thermal decomposition volatiles and prevented the spread of pyrolysis products into the gas phase. Additionally, PA-GZ-CNF composite foams achieved hydrophobicity with a water contact angle of 104.0° after hydrophobic treatment without sacrificing their flame retardancy. [ABSTRACT FROM AUTHOR]

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

• 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]

Summary: Induced by extremely inflammable characteristic, fire accidents worldwide of crops frequently occur and give rise to loss of life and personal injury. Given this problem, combustion behavior characterization of four major crops was investigated by cone calorimeter. Results confirmed the less quantity of crops needed longer time to be ignited. Meanwhile, the linear relation between the inverse square of time to ignition and heat flux of crops was found. For heat release rate (HRR), it was demonstrated that more quantity of crops prolonged the heat release process. For instance, with heat flux of 50 kW/m2, HRR values of 100 and 50 g soybean at 400 seconds were 212 and 40 kW/m2. Besides, peak values of HRR (PHRR) were close with different mass, especially for corn. Interestingly, compared to less quantity, more quantity crops were harder to be ignited at same heat flux. In addition to soybean, PHRR and total heat release (THR) of crops was gradually increased with the increasing heat flux. Meanwhile, THR values of 100 g crops were lower than double THR of 50 g crops. The investigation of combustion behavior characteristic could guide the safety storage of crops, thus avoiding the occurrence of crops fire hazards. [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]

In this study, high electrical conductivity and flame retardant electrothermal ethylene‐vinyl acetate (EVA) films were fabricated by using carbon nanotubes‐wrapped ammonium polyphosphate (CAPP) and conductive carbon black (CCB). CAPP was used as a synergistic conductive filler and flame retardant to improve the electrical conductivity and fire safety of the electrothermal film at the same time. Besides, the heat release rate (HRR) and the total heat release (THR) of EVA‐5 decreased about 81.5% and 57.3% compared with those of pure EVA film, respectively. Moreover, by incorporating a small amount of CAPP, EVA‐5 can reach up to V‐0 rating with an limiting oxygen index (LOI) value of 31%. EVA film fabricated by CCB and CAPP as conductive material exhibited almost 10 times increment on electrical conductivity than that of same content for CCB alone. And time vs temperature profiles of EVA‐5 showed a stable trend over 3600 seconds without any offset at a given applied voltage of 15 V. Moreover, its excellent cycle heating performance indicated that the electrothermal film can be recycled, which meets the requirements of sustainable development. In a word, this novel strategy provides a simple and effective way to obtain a high conductive and fire safety electrothermal film. [ABSTRACT FROM AUTHOR]

Inflammable characteristic produces an inevitable challenge for the corn storage, which endangers the food demand of human being. We investigated the combustion behavior evolvement of corn under different heat flux, with the aid of cone calorimeter. The reciprocals of square rooted time to ignition presented a linear relation to heat flux (y = 0.0036(q + 11.0833), R2 = 0.8944), similar to other materials. Higher peak values of heat release rate were obtained in heat fluxes of 20 kW/m2 and 25 kW/m2, due to longer heat time and moderate heat flux. Total heat release value was decreased only when heat flux was low to 10 kW/m2 and presented a significant decrease in heat flux of 5 kW/m2 (decreased to 39.0 MJ/m2 from 63.0 MJ/m2). It also found that the ignition temperature for the corn combustion was near 365°C; meanwhile, the surface temperature of corn combustion was higher with higher heat flux. As the XPS analysis presented, the main elements of combustion residue under 35 kW/m2 were C 1s, O 1s, Ca 2p, K 2p, B 1s, and Si 2s. Results from Raman spectra and XRD curves indicated that the graphitization degree of combustion residue was gradually decreased with increase of heat flux. [ABSTRACT FROM AUTHOR]

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

[Display omitted] 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] • 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]

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

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

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

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

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

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

[Display omitted] • The polyaniline (PANI) is deposited on the surface of two-dimensional Ti 3 C 2 to obtain the Ti 3 C 2 @PANI hybrid for constructing waterborne polyurethane (WPU) composite. • Due to the existence of conductive fillers and the isolated structure, the electromagnetic shielding effectiveness of Q-FBP-WPU/Ti 3 C 2 @PANI composite is still higher than 20 dB after hundreds of stretching and bending. • The cone test results show that the peak heat release rate of Q-FBP-WPU/Ti 3 C 2 @PANI is decreased by 46.2%. To solve the increasing serious electromagnetic radiation pollution and limitations of metal-based electromagnetic shielding materials in flexible devices, the polyaniline (PANI) is deposited on the surface of two-dimensional Ti 3 C 2 to obtain the Ti 3 C 2 @PANI hybrid for constructing waterborne polyurethane (WPU) composite. Meanwhile, to address the flame risk of WPU composite, the two-dimensional black phosphorous (BP) is incorporated as a flame retardant to prepare isolated flame-retardant black phosphorous-waterborne polyurethane/Ti 3 C 2 @polyaniline(Q-FBP-WPU/Ti 3 C 2 @PANI) composite with isolated structure. Due to the existence of conductive fillers and the isolated structure, the Q-FBP-WPU/Ti 3 C 2 @PANI composite exhibited the highest electrical conductivity (2.23 S/m) and the electromagnetic shielding effectiveness (EMI SE) of 27.3 dB in the frequency range of 8.2–12.4 GHz (X-band) and retains higher than 20 dB after hundreds of stretching and bending, which completely satisfies the commercial demands. Compared with the composite with a disordered structure, the thermal conductivity of Q-FBP-WPU/Ti 3 C 2 @PANI is increased by 93.3%. The cone test results show that the peak heat release rate, total heat release, total smoke production and total CO production of Q-FBP-WPU/Ti 3 C 2 @PANI is decreased by 46.2%, 16.3%, 21.2% and 15.5% than that of pure WPU, certifying the fire safety of WPU are greatly improved. This work supports a novel and applicable idea for constructing functional electromagnetic shielding materials. [ABSTRACT FROM AUTHOR]

A fully bio-based epoxy thermosetting network was prepared by curing a renewable luteolin-derived epoxy resin (DGELU) with a furan-derived hardener, 5, 5′-methylenedifurfurylamine (DFA). For comparison, a control sample was prepared by curing the petroleum-based commercial epoxy diglycidyl ether of bisphenol A (DGEBA) with a petroleum-based hardener, 4, 4′-diaminodiphenylmethane (DDM). The glass transition temperature (T g) was found to be 216 °C for the cured DGELU/DFA, which was 67 °C higher than that of the cured DGEBA/DDM. The storage modulus at 30 °C and the tensile strength of the cured DGELU/DFA were 82.5 % and 23.2 % higher than those of the cured DGEBA/DDM. The benzopyrone unit of the luteolin structure was conducive to exceptional charring, and the char yield for thermal decomposition in the nitrogen of the cured DGELU/DFA was 3.2-fold higher than that for the cured DGEBA/DDM. As expected, the cured DGELU/DFA displays a relatively high limiting oxygen index (LOI) of 38.0 % and a UL-94 V-0 classification, whereas the petroleum-based counterpart exhibited a much lower LOI of 24.0 % and no classification in the UL-94 test. An in-vitro cytotoxicity study indicated that the cured DGELU/DFA showed no cytotoxic effect against normal fibroblast cells after 24 and 72 h. Because of these fascinating features, the DGELU/DFA thermosetting network was deposited onto wood surfaces for evaluation as a flame-retardant coating. Compared with the wood treated using the cured DGEBA/DDM coating, wood coated with the cured DGELU/DFA showed a super fire-safe property that could lead to a 55.8 %, 12.4 %, and 11.5 % decrease in peak heat release rate (PHRR), total heat release (THR), and total smoke production (TSP), respectively. An anti-flammable, high strength and non-toxic bio-derived epoxy thermosetting network for highly safe epoxy coating applications has been developed. • A fully bio-based epoxy thermoset (DGELU/DFA) has been prepared from luteolin. • DGELU/DFA showed higher Tg and tensile strength than its petroleum-based counterpart. • DGELU/DFA displayed anti-flammability with a high LOI of 38.0 % and a UL-94 V-0 grade. • DGELU/DFA showed no cytotoxic effect against normal fibroblast cells. • DGELU/DFA is suitable as a flame-retardant and eco-friendly coating for wood. [ABSTRACT FROM AUTHOR]

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

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

[Display omitted] • BP-Ti 3 C 2 nanohybrids were obtained by two-electrode electrochemical exfoliation method. • The smoke release of WPU/BP nanocomposites during combustion was suppressed with the introduction of Ti 3 C 2. • The mechanical properties and fire safety of WPU were simultaneously improved. The low exfoliation yield and large solvents consumption have become the major issue that limits the commercial application of two-dimensional nanomaterials. Emerging as an effective and environmentally friendly approach, electrochemical exfoliation has been attached by extensive concern. Hence, a simple and environmentally friendly two-electrode electrochemical exfoliation method was put forward to prepare black phosphorus-MXene (BP-Ti 3 C 2) nanohybrids without consumption of any organic solvents. The integration of BP and Ti 3 C 2 also imparts higher fire safety and mechanical properties to waterborne polyurethane (WPU). With the incorporation of 2.0 wt% BP-Ti 3 C 2 , the peak heat release rate, total heat release, total smoke production and total CO 2 yield of WPU were decreased by 42.2%, 12.9%, 12.6% and 16.5%, respectively, exhibiting a great flame retardancy effect. The employment of electrochemical exfoliation method towards BP and Ti 3 C 2 nanosheets not only imparts higher fire safety to polymer composites, but also provides a referable environmentally friendly preparation for two-dimensional nanomaterials. [ABSTRACT FROM AUTHOR]

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

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

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

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

[Display omitted] • Few-layer black phosphorus was prepared via a simple hydrothermal Li+ intercalation method. • Aryl diazonium modified black phosphorus/ ultrafine yttrium oxide promisingly reduced the fire hazard of epoxy resins. • The possible mechanism of radical removal and catalytic carbonation was put forward. • This work might have a promising prospect for developing efficient covalent functionalized BP nanocomposites. Black phosphorus (BP), as a promising star of two-dimensional (2D) van der Waals family, has attracted extensive attention for its characteristic dimension effects, mechanical properties and thermal stability. Herein, we report a facile strategy of integrating aryl diazonium modified few Layer black phosphorus with loading of ultrafine yttrium oxide (BP-NH-Y), for reducing the fire hazard of epoxy resin (EP). The results of cone calorimetry test results manifest that the flame retardancy of EP can significantly improve by adding 2 wt% BP-NH-Y, for instance, the peak heat release rate (pHRR) and the total heat release (THR) is reduced by 47.0% and 48.1%, respectively. Especially, adding the BP-NH-Y nanosheets distinctly inhibite the diffusion of EP pyrolysis products (such as toxic CO, hydrocarbons etc.) during flaming. In particular, epoxy composites with only 1.0 wt% BP-NH-Y were able to achieve UL-94 V-0 rating with an oxygen index of more than 30. This work may have a promising prospect for developing efficient covalent functionalized BP nanosheets to meet the needs of sustainable applications. [ABSTRACT FROM AUTHOR]

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

There are many applications for epoxy resin as a coating material in the automotive, electronics, and aerospace industries. However, when derived from petrochemical industries, adversely affect the environment, as they are rigid and resistant to recycling due to inherent cross-linked structure. In the present study, we prepared green epoxy resin from renewable resources, able to replace the conventionally produced DGEBA thermoset. Initially, we synthesized an epoxy thermoset from vanillin-derived Schiff base epoxy monomer (VTA-EP) that was thermally cured with bio-based 5, 5′-methylenedifurfurylamine (DFA). Due to the unsaturated double bond in cured VTA-EP/DFA thermoset displayed a relatively high glass transition temperature (T g ~ 170 °C) than the DGEBA/DDM system. Also, tensile strength (60 MPa), storage modulus (3271 MPa), and elongation at break (2.8%) were higher. Additionally, the peak of heat release rate (PHRR) and the total heat release (THR) of the cured VTA-EP/DFA resin decreased, and LOI and UL-94 ratings were improved. The green epoxy thermoset exhibited good dissolution in various acidic conditions due to the degradability of the Schiff base network in contrast to DGEBA/DDM. This work demonstrates that the combination of biomass with Schiff base structure provides a versatile platform for the fabrication of multifunctional vanillin-derived epoxy thermosets. [Display omitted] • A fully bio-based epoxy resin derived from vanillin was synthesized. • The fully bio-based epoxy resin system showed excellent intrinsic flame retardancy. • The fully bio-based epoxy resin possessed excellent acidity and temperature-controlled degradability. [ABSTRACT FROM AUTHOR]

• A liquid flame retardant, phosphorus-containing triacrylate, was synthesized. • Flexible polyurethane/phosphorus-containing polyacrylate IPN foams were prepared by simultaneous strategy. • Flame retardancy, thermal stability and mechanical properties of IPN foams were improved concurrently. Even though organophosphorus additives can improve flame retardancy and compress strength of flexible polyurethane foam (FPUF), but thermal stability and resilience are deteriorated. In this work, phosphorus-containing monoacrylate and triacrylate, (dimethoxyphosphoryl)methyl acrylate (DMPMA) and tris(acryloyloxymethyl)phosphine oxide (TAMPO), were synthesized. The liquid DMPMA and/or TAMPO were added into FPUF ingredients with radical initiator and polymerized in the heating process after foaming to form FPUF/polyacrylate composites. The neat and modified foams were controlled to have similar densities. Gel content of more than 96% was obtained for FPUF incorporated with TAMPO. And structure of interpenetrating polymer network (IPN) of FPUF3-5 loaded 20 wt% DMPMA and TAMPO of polyol (ratio of 3:1, 1:1 and 1:3 respectively) was further confirmed by their bicontinuous phase morphology with nanoscale domain uniformly distributed. All modified foams attain improved flame retardancy. Simultaneously increased thermal stability, compression force deflection (CFD) value and resilience were achieved by FPUF4-5. Especially, FPUF4 exhibits satisfied flame retardancy (limited oxygen index of 22.1%, pass of TB117-2000 vertical burning test, prolonged time to ignition, 49% decrement of peak heat release rate and 33% reduction of total heat release), elevated thermal stability and improved compressive (15% improvement of CFD) and resilient (5.2% raise of resilience) properties, concurrently. Therefore, DMPMA and TAMPO have great potential as liquid additive-type flame retardants for manufacturing flame retardant, supportive and comfort FPUF in seating and cushioning applications. [ABSTRACT FROM AUTHOR]

• A bio-based epoxy monomer (HECarCP) was synthesized from cardanol and cyclophosphazene. • HECarCP/DDM thermoset showed a high LOI value of 33.0% and UL-94 V-0 classification. • Peak heat release rate of HECarCP/DDM was 63% lower than that of DGEBA/DDM. • Total smoke production of HECarCP/DDM was 72% lower than that of DGEBA/DDM. • HECarCP/DDM displayed much better toughness than the DGEBA/DDM. Petroleum-based diglycidyl ether bisphenol A (DGEBA)-type epoxy is one of the most popular thermosetting materials currently, but it suffers from brittleness, flammability and non-renewability. In this study, an intrinsically flame retardant bio-based epoxy monomer (HECarCP) was synthesized from cardanol and cyclophosphazene. Subsequently, HECarCP was cured by 4,4'-diaminodiphenyl methane (DDM) to obtain a thermosetting material. Compared to the cured DGEBA/DDM thermoset, the cured HECarCP/DDM thermoset showed lower initial decomposition temperature; however, the earlier thermal decomposition caused by cyclophosphazene core contributed to char formation in return. As well, the HECarCP/DDM exhibited slightly lower tensile strength but much higher elongation at break than the DGEBA/DDM, overcoming the drawback of brittleness of the DGEBA/DDM. More importantly, the cyclophosphazene core provided intrinsic flame retardancy to the HECarCP/DDM thermoset, which displayed a relatively high LOI value of 33.0% and UL-94 V-0 classification. In cone calorimeter measurement, the peak heat release rate, total heat release and total smoke production of the HECarCP/DDM thermoset was declined by 63%, 24% and 72%, respectively, compared to those of the DGEBA/DDM, owing to the formation of a thermally stable and insulating char layer during combustion. This study paves the way for broadening applications of cardanol in fabrication of high-performance bio-based thermosetting polymers with excellent comprehensive properties. [ABSTRACT FROM AUTHOR]

• A dual interaction-based and bio-inspired LbL assembled coating was prepared. • Improved flame retardancy and super-hydrophilicity of PA6.6 fabrics were realized. • Simultaneous PCS grafting and LbL deposition with 8 QLs raised LOI value up to 23.5%. • A reduction in pHRR by 45% and in THR by 25% was achieved with 8 QLs deposition. • The dual-interaction in LbL assembly could stabilize coatings up to 20 laundering cycles. A dual interaction-based (i.e., ionic/covalent) deposition of carbohydrate polymers, namely chitosan (CS) and oxidized sodium alginate (OSA) along with a plant-derived phosphorus-rich compound like phytic acid (PA) and a nitrogen rich compound like melamine (ME) was considered onto the phosphorylated chitosan (PCS) modified polyamide 6.6 (PA6.6) fabric surfaces in order to impart durable flame retardancy along with super-hydrophilicity of the same. Firstly, the pure PA6.6 textile surfaces were modified by PCS via UV-induced grafting and subsequently, the above-mentioned polyelectrolytes were assembled onto the fabric surfaces in a quadralayer fashion [i.e., (CS/ME-OSA-CS/ME-PA) n ; "n" represents the number of quadralayers (QLs)]. Here, the amino groups of CS/ME and the aldehyde groups of the OSA were stabilized via covalent interaction and the deposition of positively charged CS/ME and negatively charged phytic acid (PA) formed ionic interaction. In the vertical burning (UL-94) test, both the only PCS grafted and the simultaneously PCS-grafted along with LbL assembled fabrics could completely stop the melt dripping tendency and attained a V-1 rating. In the meantime, the limiting oxygen index (LOI) value received a moderate increase from 18.5 % of pure PA6.6 to 23.5 % for the PCS grafted and 8-QLs deposited fabric sample (i.e., PA6.6-g-PCS-8QL). Moreover, the PA6.6-g-PCS-8QL fabric sample exhibited a dramatic decrease in the peak heat release rate (pHRR) and total heat release (THR) by about 45 % and 24.7 % respectively alongside enhanced thermal stability. Apart from the appreciable flame retardancy, this fabric sample (i.e., PA6.6-g-PCS-8QL) could boost up the hydrophilicity to attain a water contact angle of 0°. Finally, this dual interaction-based deposition of bio-inspired polyelectrolytes posed a positive impact in enhancing the coating stability in laundering and imparting durable flame retardancy to sustain even up to 20 laundering cycles. [ABSTRACT FROM AUTHOR]

• Few-layer BP was scalable exfoliated by solvent-heat method via ion intercalation. • BP-PDA nanohybrids showed remarkable decrease in PHRR, THR and the amount of CO. • Significant tensile strength enhancement was achieved due to the adhesion effect. • PVA/BP-PDA exhibited high air stability even after exposed to air for five months. As a rising star of two-dimensional (2D) materials, single or few-layer black phosphorus (BP) possess great potential as nanofiller in fabricating polymer nanocomposites, due to its thermodynamic stability, nano-size effect and structural characteristics. Herein, few-layer BP nanosheets were scalable exfoliated via solvent-thermal method, the Lithium ion intercalation was achieved during this procedure. Follow by a polydopamine (PDA) encapsulated BP sandwich nanostructure was developed by oxidation–reduction strategy, which improved the air stability of few-layer BP and its interfacial compatibility with polymer matrix. As could be expected, the PDA encapsulated BP (BP-PDA) can effectively enhance the mechanical properties and flame retardancy of polyvinyl alcohol (PVA) nanocomposite films. For instance, the PVA/BP-PDA5.0 nanocomposite film loaded with 5 wt% BP-PDA exhibited 57.2% maximum decrease in peak heat release rate and 47.9% maximum reduction in total heat release. Meanwhile, while the BP-PDA loading achieved 2 wt%, PVA/BP-PDA2.0 nanocomposite film revealed an 81.1% increase in the tensile strength. In particular, on account of dual protection of the PDA encapsulation and polymer matrix embedding, the air stability of BP in PVA matrix was significantly improved. As an evidence, the ratio of A g 1/A g 2 in Raman spectra of BP-PDA decreased from the initial 0.72 to 0.62, even after exposed to air for five months, indicating a low level of oxidation. This work provides a novel strategy for scalable exfoliation and functionalization of BP, and enables a wide range of potential applications of BP in polymer nanocomposites. [ABSTRACT FROM AUTHOR]

• Innovation: novel g-C 3 N 4 @PPZ to promote flame retardant and toughness of BMI. • High-efficiency: PHRR and TSPR of BMI/g-C 3 N 4 @PPZ2.0 reduced by 52.1%, 53.8%. • The best impact strength of BMI/g-C 3 N 4 @PPZ increased by 184.0%. • Mechanism: the flame retardant and toughening mechanism was proposed. It's acknowledged that the inferior toughness of bismaleimide resin (BMI) is the crucial problem hindering its development and application especially in aerospace, mechanical and electronic fields. While the poor fire safety of toughened BMI is another problem urgently needed to be resolved. Therefore a novel g-C 3 N 4 @PPZ hierarchical architecture constituted of porous g-C 3 N 4 tubes modified by polyphosphazene was designed and fabricated to improve the fire safety and mechanical properties of BMI in this work. Especially compared to pure BMI, the peak heat release rate (PHRR) and peak smoke production rate (PSPR) of BMI with an incorporation of 2 wt% g-C 3 N 4 @PPZ (BMI/g-C 3 N 4 @PPZ2.0) are at 246.3 kW/m2 and 0.12 m2/s accompanying with 52.1% and 53.8% reduction respectively. The total heat release (THR) and total smoke production (TSP) of BMI/g-C 3 N 4 @PPZ2.0 are endowed with reductions of 29.4% and 42.9% as well, which demonstrates that the fire safety including heat and smoke hazards of BMI/g-C 3 N 4 @PPZ2.0 is significantly improved. With regard to the mechanical performance of BMI composites, the impact strength of BMI/g-C 3 N 4 @PPZ1.5 is 18.89 kJ/m2 which increases by 184.0% in comparison with that of pure BMI resin (6.65 kJ/m2). And it's found that the impact strength of BMI/g-C 3 N 4 @PPZ are still higher than pure BMI in hot-humid environment, which signifies that the BMI/g-C 3 N 4 @PPZ would be preferred in the industrial applications. Meantime the possible flame retardant and toughening mechanism of g-C 3 N 4 @PPZ in BMI is detailed investigated and proposed as well. [ABSTRACT FROM AUTHOR]

Similar to graphene, few-layer black phosphorus possesses many excellent properties such as good thermal stability, mechanical properties and unique characteristic dimension effects, which is considered as promising nanoadditives. But the low yield and inferior interfacial adhesion with polymer matrix are unavoidable obstruction to fabricate high performance nanocomposites. Herein, we report a facile and environmentally friendly approach to simultaneously exfoliate and modify black phosphorus (BP) by electrochemical cathodic exfoliation, where BP crystal acted as the cathode and ethylene imine polymer (PEI) acted as electrolyte and modifier. The positively charged PEI would uniformly anchor on the surface of the newly peeled-off BP nanosheets through electrostatic attraction effect, resulting in preventing the agglomeration of BP nanosheets and improve the compatibility between BP and waterborne polyurethane (WPU) matrix. Significantly, with the addition of 2.0 wt% PEI modified BP in WPU matrix, the fire safety of WPU composites was enhanced. The peak heat-release rate, total heat release, total smoke production and total CO yield are decreased by 34.3%, 21.2%, 22.3% and 50.2% compared to pure WPU, respectively. Also, the tensile strength of WPU composites was increased by 71% (from 21.9 to 31.0 MPa) at the cost of the breaking elongation slightly decreased by 5.6%. This work provides the possibility for the scalable preparation and a real application of BP in polymer nanocomposites. Image 1 • A facile and environmental route to simultaneously exfoliate and modify BP. • BP-PEI had good flame-retardant contributions in both gaseous and condensed phase. • Functionalized BP enhanced flame-retardant properties of WPU composite. [ABSTRACT FROM AUTHOR]

Cotton fabrics are prone to ignite fire accidents as well as breed bacteria and fungi, which have hampered their applications in the field of packaging and home decorations. Guanazole complexes with silver and zinc ions were deposited to cotton fabrics through self-assembly to prepare the flame-retardant and antibacterial cotton fabrics. The effect of the guanazole-metal complexes on the morphological structure, flammability and thermal degradation of cotton fabrics was studied by field emission scanning electron microscopy, limiting oxygen index (LOI), UL-94 vertical burning test, and thermogravimetric analysis. The antibacterial and antifungal activities of the coated fabrics were evaluated as well. The guanazole-zinc and guanazole-silver treated cotton fabrics showed a high LOI of 29.5% and 27.5%, respectively. In the vertical burning test, both the guanazole-zinc and guanazole-silver treated cotton fabrics self-extinguished when removing the ignition source, displaying a UL-94 V-0 classification, while the untreated one and the guanazole-treated one burned out. Thermogravimetric analysis results confirmed that the guanazole-metal complexes promoted the thermal decomposition of cotton and thus improved the char yield significantly. Micro-scale combustion calorimeter measurements clarified that the guanazole-zinc and guanazole-silver treated cotton displayed dramatically decreased peak heat release rate (64.4% and 59.1%, respectively) and total heat release (26.4% and 14.8%, respectively) in comparison to the untreated one. The significantly improved flame retardancy of guanazole-metal complexes treated cotton fabrics could be attributed to their enhanced charring capability that blocked flammable volatiles into flame zone. The treated cotton fabrics with guanazole-metal complexes exhibited better antibacterial capacity against Staphylococcus aureus and Escherichia coli than the untreated and guanazole-treated ones. Furthermore, the guanazole-silver treated cotton fabrics also showed good antifungal activity against Penicillium, Fusarium chlamydosporum and Aspergillus niger. Image 1 • Guanazole-metal complex was used to simultaneously improve flame retardant and antibacterial property of cotton fabrics. • Limiting oxygen index increases to 27.5% for guanazole-silver treated cotton from 19.5% for untreated one. • The peak heat release rate of guanazole-silver treated cotton was reduced by 59% compared to untreated one. • The guanazole-silver treated cotton showed self-extinguishing behaviors owing to promotion of char formation. • The guanazole-silver treated cotton showed good antibacterial and antifungal ability. [ABSTRACT FROM AUTHOR]

• Flame-retardant and superhydrophobic coatings were constructed on cotton fabrics by a facile two-step method. • The treated cotton showed super flame retardancy in terms of self-extinguishing behavior. • The peak heat release rate of the treated cotton was significantly reduced by 70% compared to pure cotton. • The treated cotton exhibited fascinating anti-fouling and water-oil separation abilities. • The coatings on cotton fabrics displayed good abrasion resistance and washing durability. A flame-retardant and superhydrophobic coating was deposited on cotton fabrics using a simple two-step spraying method. In detailed, the first step involved flame-retardant layer consisted of alkylammonium functional silsesquioxane (A-POSS)/phytic acid (PA) complex, while the second step generated superhydrophobic layer that was composed of hierarchical structured titanium oxide@polydimethylsiloxane (TiO 2 @PDMS) composite. The influence of the components' loading in the coating on flame-retardant, thermal and wetting properties of the coated cotton fabrics was investigated systematically. The optimized coated cotton sample denoted as C3-PDMS-TiO 2 was screened through limiting oxygen index (LOI), UL-94 flammability test, cone calorimetry measurement and water contact angle (WCA). Specifically, C3-PDMS-TiO 2 sample showed self-extinguishing behavior in the vertical burning test, as well as a significantly enhanced LOI to 29% from 18% for pristine cotton fabrics. Furthermore, the peak heat release rate (PHRR) and the total heat release (THR) values of C3-PDMS-TiO 2 were significantly declined by 70% and 41%, respectively, compared to those of pristine cotton fabrics. Additionally, C3-PDMS-TiO 2 exhibited super self-cleaning ability as a consequence of its superhydrophobic surface. Furthermore, C3-PDMS-TiO 2 was applied for water-oil separation, and exhibited robust ability even in strong acid- or alkali-oil mixtures. The C3-PDMS-TiO 2 fabrics also displayed super abrasion resistance (WCA > 139° after 50 abrasion cycles) and washing durability (self-extinguishing after 5 laundering cycles). This facile finishing technique has great potentials in application as multifunctional advanced textiles. [ABSTRACT FROM AUTHOR]

As is well known, polyethylene (PE) is flammable with the release of abundant heat, confirming its low fire safety. Consequently, the extended application of PE is restrained. In this work, we propose the facile preparation of multi-component hybrid (functionalized montmorillonite anchored with ZnO, defined as FMZH) and its promising utilization in PE. With the aid of functionalized compound, the obtained hybrid shows good dispersion state, as well as strong interfacial interaction with polymer matrix. By incorporating FMZH fillers, the marked reductions in peak heat release rate (PHRR) and total heat release (THR) can be obtained, corroborating the enhanced fire safety. Specifically, with the addition of 5.0 wt% 1-2FMZH and 1-4FMZH, the PHRR values are reduced to 567 and 667 kW/m2, respectively, corresponding to 54.7 and 46.8% decrease. Also, the suppressing effect on the release of decomposition fragments can be evidenced by the decreased absorbance intensity in FTIR spectra. Furthermore, the presence of these fillers shows marginal influence on the nonisothermal crystallization behavior of PE. Additionally, the FMZH composite with hierarchical structure shows superior gas barrier function over pristine ZnO and montmorillonite. • Preparation of multi-component hybrid of FMZH is proposed. • With the aid of functionalized compound, the obtained hybrid shows good dispersion. • By adding FMZH fillers, the marked reductions in peak heat release rate are obtained. • This hierarchical structure of FMZH shows more superior gas barrier function. [ABSTRACT FROM AUTHOR]

In this work, a novel three-dimensional nanoarchitecture metal-organic framework@polyaniline (Sn-MOF@PANI) was designed and applied to address the fire hazards of epoxy resins (EP). Fourier transform infrared (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) results proved that the Sn-MOF@PANI was successfully synthesized. Compared with pure EP, the peak heat release rate (PHRR) and the total heat release (THR) of EP/Sn-MOF@PANI were reduced by 42% and 32%, respectively. Meanwhile, the total smoke production (TSP) and total gaseous products of EP/Sn-MOF@PANI were also reduced during the combustion. The above results illustrate that the fire safety of EP was improved. Based on the analysis of the gaseous products and the condensed phase, a possible flame retarding mechanism was proposed. Moreover, the addition of Sn-MOF@PANI improved mechanical properties of EP, including storage modulus and impact strength. Image 1 • A Sn-based metal organic framework@polyaniline (Sn-MOF@PANI) was synthesized. • When the loading was 2 wt%, EP/Sn-MOF@PANI showed good flame retardancy. • Based on the analysis of the gaseous products and the condensed phase, a possible flame retarding mechanism was proposed. • EP/Sn-MOF@ PANI had better mechanical properties than pure EP. [ABSTRACT FROM AUTHOR]

Flexible polyurethane (FPU) foam as a primary softening material is utilized in soft furnishings of upholstered mattresses and furniture. High flammability of this soft furnishing material usually leads to residential fires, causing severe fatalities. In the present study, we proposed a bio-based and environmentally-friendly flame retardant multilayered coating consisted of laponite (LAP), branched polyethyleneimine (BPEI), sodium alginate (SA) and chitosan (CH) that was deposited onto FPU foams to enhance their fire safety property. Based on the thermogravimetric analysis results, it was indicated that after the deposition of LAP, the thermal stability of the coated FPU foams increased sharply. Foam treated with 9 quad layers (QL) of BPEI/SA/CH/LAP multilayered coating showed self-extinguishing behavior in an open flame burning test. Furthermore, the values of peak heat release rate (PHRR), total heat release (THR) and smoke release rate (SPR) of the coated FPU foams reduced considerably in comparison to those of the pure FPU foam. Specifically, 9 QLs of BPEI/SA/CH/LAP declined the PHRR and the THR by 74% and 42.6%, respectively. The coated FPU foam also showed self-extinguishing and anti-dripping features in an open flame testing. Therefore, it can be stated that LAP-based coating has incredible benefits in decreasing fire risk of FPU foams. Moreover, the flame retardant mechanism of this LAP-based multilayered coating was proposed. The LAP-based coating functioned as a physical insulating barrier that successfully retarded the permeation of the flammable volatiles, heat and oxygen. Hence, the significant decrease in PHRR with the self-extinguishing behavior was achieved, implying promising potential of this LAP-based multilayered coating to enhance the fire safety of FPU foams. • Laponite-based inorganic-organic hybrid coating is deposited on FPU foams. • The coated FPU foam shows a 74% lower peak heat release rate than the uncoated one. • The coated FPU foam exhibits a 62% lower smoke production rate than the uncoated one. • Laponite strengthens the barrier effect that accounts for reduced fire hazards. [ABSTRACT FROM AUTHOR]

• Cuprous oxides with sheet morphology (Mn@Cu 2 O-M nanosheets) are rationally designed and successfully prepared. • The prepared Mn@Cu 2 O-M sheets could endow epoxy composites with high flame retardancy and smoke suppression properties. • The mechanism are probably due to the physical barrier effect and catalytic carbonization awarded by Mn@Cu 2 O-M sheets. To date epoxy resins have been extensively used in the field of chemical engineering, aerospace and building materials. Nevertheless, the utilization of flammable epoxy resins has posed a huge threat to lives and properties, which restricted their applications. In this work, manganese-based cuprous oxides two-dimensional nanosheets (Mn@Cu 2 O-M) are rationally designed and successfully prepared to improve the toxic effluent elimination of epoxy resin. The fire safety properties of the prepared Mn@Cu 2 O-M based nanocomposites improved the heat release rate (<35 %) and total heat release (<40 %) compared to the control epoxy. Moreover, the production of smoke and toxic volatiles of the composites with Mn@Cu 2 O-M nanosheets is significantly reduced. The mechanism investigations indicate that the improved flame retardancy and toxic effluent elimination of epoxy composites are attributed to the physical barrier effect and catalytic carbonization awarded by Mn@Cu 2 O-M nanosheets during burning. This work provides a promising strategy to develop eco-friendly, efficient and fire-safe polymers by both physical barrier effect and catalytic carbonization. [ABSTRACT FROM AUTHOR]

• The ambient stability was imparted to BP nanosheets. • The radicals quenching effect of TA was developed to reduce the CO release. • The flame retardancy and toxic gases suppression of BP nanosheets was explored. Herein, as a natural antioxidant, tannin (TA) is firstly used to functionalize black phosphorous (BP) nanosheets to improve the ambient stability and toxic suppression, thus decreasing the fire hazards of polymer materials. Compared to pure BP nanosheets, higher temperature for thermal oxidation decomposition is achieved for TA-BP nanosheets, directly confirming the ambient stability of TA-BP nanosheets. Meanwhile, from high resolution TEM and XPS results, TA-BP nanosheets after being exposed at air for 10 days present well-organized crystal structure and low PO x bonds content. Cone calorimeter results illustrate that the incorporation of 2.0 wt% TA-BP nanosheets significantly decreases the peak value of heat release rate (−56.5 %), total heat release (−43.0 %), CO 2 concentration (−57.3 %) of TPU composite. Meanwhile, with addition of low to 1.5 wt%, the release of highly-toxic CO gas is significantly suppressed, confirmed by lower peak value (0.52 mg/m3) and decreased total release amount (−55.1 %). The obviously enlarged tensile strength (36.7 MPa) and desirable elongation at break (622 %) are also observed. This strategy not only firstly adopts bio-based antioxidant to impart excellent environmental stability for BP nanosheets, but also promotes the promising potentials of BP nanosheets in the fire safety application of polymer composites. [ABSTRACT FROM AUTHOR]

Polystyrene sulfonate functionalized graphene nanosheets (PSS@GNS) with high quality (I D /I G = 0.17) were fabricated through electrochemical exfoliation of bulk graphite followed by simple free radical polymerization in water solution, which is a promising strategy for mass production of polymer functionalized graphene. P-styrene sulfonate anions were used to intercalate into the bulk graphite under voltage and also as monomers of the macromolecule modification agents for the exfoliated graphene nanosheets. Besides, benzene rings and carbon double bonds are considered to be able to capture hydroxyl free radicals which produce defects on graphene sheets during electrochemical exfoliation process, thus improve the quality of the exfoliated graphene nanosheets. Then the graphene nanosheets were incorporated into polystyrene (PS) through a solution blending method to reduce the fire hazards and improve mechanical properties of PS resin. According to the results of cone calorimeter, the introduction of functionalized graphene nanosheets into PS reduces heat release rate (decreased by 40%), total heat release (decreased by 35%) and increases the amount of char residues. The flame retardant improvement is attributed to the barrier effect of well-dispersed graphene nanosheets, limiting the mass transfer of the volatile compounds and forming char layers which blocked polymers from heat and oxygen. Meanwhile, the introduction of PSS@GNS into PS also contributed to increase its strength and elongation rate thanks to the pristine properties of graphene nanosheets and their interfacial interaction with the PS matrix. • This method to fabricate functionalized graphene nanosheets in aqueous solution is easy to operate. • Obtained graphene nanosheets with high quality and few defects were functionalized by polystyrene sulfonate. • Fire safety and mechanical strength of the functionalized graphene/polystyrene nanocomposites were improved. • Favorable dispersion, compatibility and interfacial interaction contributed to the enhancement of PS nanocomposites. [ABSTRACT FROM AUTHOR]

The inherent chemical inertness presents a huge challenge for the functionalization of hexagonal boron nitride (h-BN), thus limiting its potential in flame retardant and toxic gas suppression of thermoplasticity polyurethane (TPU). Here, with the assistance of Lewis acid-base interactions, an operable platform formed by SiO 2 coating is constructed onto the surface of h-BN nanosheets, offering an opportunity for introducing phytic acid (PA). The resultant h-BN nanohybrids present an enhancement effect for flame retardancy of thermoplastic polyurethane (TPU), confirmed by obvious reductions in peak value of heat release rate (−23.5%) and total heat release (−22.1%). Meanwhile, the smoke product rate and total smoke release of TPU composite containing 2.0 wt% h-BN nanohybrids are decreased by 29.2% and 8.6%, respectively. Through CO 2 detector and AtmosFIR, specially, it is found that the toxic gases (CO, CH 4 , C 2 H 6 , TOC) are turned into CO 2. Through a series of analytic methods, it was found that the introduced PA suffered from a pre-gradation process to release P-containing compounds, reacting with TPU matrix to produce protective char. In addition, the presence of SiO 2 was also contributed to improve the robustness of char residue. In view of high temperature condition, the catalysis effect of h-BN is responsible for the conversion of toxic gases. Therefore, the enhanced fire safety of TPU was attributed to the cooperation mechanism of h-BN, SiO 2 , and PA. Such a functionalization approach provides a novel route to overcome the chemical inertness of h-BN, thus promoting its application in fire safety fields of polymer materials. Image 1 • Chemical inertness of h-BN nanosheets was overcame. • Heat release of TPU was decreased by h-BN@SiO 2 @PA. • Toxic combustion gases were turned into CO 2. • The break strength of TPU was effectively enhanced. [ABSTRACT FROM AUTHOR]