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The effect of varying the weight percentage composition (wt.%) of low-cost expandable graphite (EG), ammonium polyphosphate (APP), fibreglass (FG), and vermiculite (VMT) in polyurethane (PU) polymer was studied using a traditional intumescent flame retardant (IFR) system. The synergistic effect between EG, APP, FG, and VMT on the flame retardant properties of the PU composites was investigated using SEM, TGA, tensile strength tests, and cone calorimetry. The IFR that contained PU composites with 40 wt.% EG displayed superior flame retardant performance compared with the composites containing only 20 w.t.% or 10 w.t.% EG. The peak heat release rate, total smoke release, and carbon dioxide production from the 40 wt.% EG sample along with APP, FG, and VMT in the PU composite were 88%, 93%, and 92% less than the PU control sample, respectively. As a result, the synergistic effect was greatly influenced by the compactness of the united protective layer. The PU composite suppressed smoke emission and inhibited air penetrating the composite, thus reducing reactions with the gas volatiles of the material. SEM images and TGA results provided positive evidence for the combustion tests. Further, the mechanical properties of PU composites were also investigated. As expected, compared with control PU, the addition of flame-retardant additives decreased the tensile strength, but this was ameliorated with the addition of FG. These new PU composite materials provide a promising strategy for producing polymer composites with flame retardation and smoke suppression for construction materials. [ABSTRACT FROM AUTHOR]

A high-performance smoke exhaust system is vital for maintaining a tenable environment during fire accidents evacuation. This study proposes a novel vortex flow driven smoke exhaust system to delay the smoke filling process during the atrium fire accident. The complex fluid movement and combustion reactions were predicted using Fire Dynamics Simulator, and the predicted smoke filling process was identified by the least-square method. Good agreements between numerical predictions and experimental measurements for vertical temperature, tangential velocity profile and smoke interface height were achieved. The numerical outcomes revealed that the amount of fresh air supplied, heat release rate and exhaust fan's rate determined the smoke interface's final height. A parametric study was also carried out to investigate the dominating factor in maintaining a stable vortex flow to maximize the smoke exhaust efficiency. Numerical results showed that the vortex flow smoke exhaust system could slow down the smoke filling, and the stability of the swirling fire is crucial for the system's performance. [ABSTRACT FROM AUTHOR]

A novel and hierarchical hybrid composite (MnO2@CHS@SA@Ni) was synthesized utilizing manganese dioxide (MnO2) nanosheets as the core structure, self-assembly chitosan (CHS), sodium alginate (SA) and nickel species (Ni) as surface layers, and it was further incorporated into an epoxy matrix for achieving fire hazard suppression via surface self-assembly technology. Herein, the resultant hybrid epoxy composite possessed an exceptional nano-barrier and synergistic charring effect to aid the formation of a compact layered structure that enhanced its fire-resistive effectiveness. As a result, the addition of only 2 wt% MnO2@CHS@SA@Ni hybrids led to a dramatic reduction in the peak heat release rate and total heat release values (by ca. 33% and 27.8%) of the epoxy matrix. Notably, the peak smoke production rate and total smoke production values of EP/MnO2@CHS@SA@Ni 2% were decreased by ca. 16.9 and 38.4% compared to the corresponding data of pristine EP. This was accompanied by the suppression of toxic CO, NO release and the diffusion of thermal pyrolysis gases during combustion through TG-IR results. Overall, a significant fire-testing outcome of the proposed hierarchical structure was proven to be effective for epoxy composites in terms of flammability, smoke and toxicity reductions, optimizing their prospects in other polymeric materials in the respective fields. [ABSTRACT FROM AUTHOR]

Thermoplastic polyurethane (TPU) is widely used in daily life due to its characteristics of light weight, high impact strength, and compression resistance. However, TPU products are extremely flammable and will generate toxic fumes under fire attack, threatening human life and safety. In this article, a nanohybrid flame retardant was designed for the fire safety of TPU. Herein, Co3O4 was anchored on the surface of exfoliated ultra-thin boron nitride nanosheets (BNNO@Co3O4) via coprecipitation and subsequent calcination. Then, a polyphosphazene (PPZ) layer was coated onto BNNO@Co3O4 by high temperature polymerization to generate a nanohybrid flame retardant named BNNO@Co3O4@PPZ. The cone calorimeter results exhibited that the heat release and smoke production during TPU combustion were remarkably restrained after the incorporation of the nanohybrid flame retardant. Compared with pure TPU, the peak heat release rate (PHRR) decreased by 44.1%, the peak smoke production rate (PSPR) decreased by 51.2%, and the peak CO production rate (PCOPR) decreased by 72.5%. Based on the analysis of carbon residues after combustion, the significant improvement in fire resistance of TPU by BNNO@Co3O4@PPZ was attributed to the combination of quenching effect, catalytic carbonization effect, and barrier effect. In addition, the intrinsic mechanical properties of TPU were well maintained due to the existence of the PPZ organic layer. [ABSTRACT FROM AUTHOR]

Cotton, the most popular textile fibre used today, suffers from high combustibility and a propensity for microbial growth. In this study, we used oxygen tolerant, visible light-activated free radical polymerisation to functionalise cotton with a biocompatible, fire retardant, antimicrobial coating that provided good fire retardancy when dry, and quickly absorbed water to provide exceptional fire retardancy and thermal insulation in more extreme fire conditions. The functionalised cotton, MF-cotton, had a limiting oxygen index (LOI) of 32% when dry and > 99% when wet. These exceptional fire retardancy results were confirmed by vertical burning tests and cone calorimeter testing. Wet MF-cotton was able to reduce exposure temperature by 140 °C under sustained heat exposure, displaying good thermal insulation. Good antimicrobial activity was demonstrated for MF-cotton against both gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria with bacterial reductions of 98.1% and 99.998%, respectively, and in vitro testing confirmed its biocompatibility. Finally, MF-cotton had improved tensile properties compared with untreated cotton and maintained its softness and breathability. The coating could have potential applications for fabrics used in hospitals, household soft furnishings, fire blankets, and protective clothing. [ABSTRACT FROM AUTHOR]

Increasing demands in minimization of fire risks and meeting fire safety requirements by polymers require advances in knowledge of flame-retardant materials suitable for use in fire-retardancy applications. The present work represents the seminal review of alginate/polymer-based materials as flame retardants. Alginates are suitable for this application as they represent alternatives to petroleum-based polymer feedstocks. The content of the present work is structured into four sections: synthesis and structure, including alginate synthesis and modification by polymeric conjugation; properties, including four-stage mechanism of thermal degradation; applications, including commercial information on alginates and polymers; and flame retardancy, including comprehensive summaries of test methods and published data, discussion of key parameters, eight fire retardancy mechanisms, four char generation mechanisms, and extensive quantitative analysis of polymer char formation. The final section culminates in a first-principles approach to the prediction of quantitative polymer char formation. The goal of the review is to provide guidance for the application of alginates and alginates conjugated with fire-retardant polymers as a new generation flame retardant material. [ABSTRACT FROM AUTHOR]

Recent discoveries of two-dimensional transitional metal based materials have emerged as an excellent candidate for fabricating nanostructured flame-retardants. Herein, we report an eco-friendly flame-retardant for flexible polyurethane foam (PUF), which is synthesised by hybridising MXene (Ti 3 C 2 ) with biomass materials including phytic acid (PA), casein, pectin, and chitosan (CH). Results show that coating PUFs with 3 layers of CH/PA/Ti 3 C 2 via layer-by-layer approach reduces the peak heat release and total smoke release by 51.1% and 84.8%, respectively. These exceptional improvements exceed those achieved by a CH/Ti 3 C 2 coating. To further understand the fundamental flame and smoke reduction phenomena, a pyrolysis model with surface regression was developed to simulate the flame propagation and char layer. A genetic algorithm was utilised to determine optimum parameters describing the thermal degradation rate. The superior flame-retardancy of CH/PA/Ti 3 C 2 was originated from the shielding and charring effects of the hybrid MXene with biomass materials containing aromatic rings, phenolic and phosphorous compounds. [ABSTRACT FROM AUTHOR]

In order to improve the flame retardant of polylactide (PLA), the synergistic effect of graphitic carbon nitride (g‐C3N4) with commercial‐available flame retardants melamine pyrophosphate (MPP) and 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) was investigated. The PLA composites containing 5 wt% g‐C3N4 and 10 wt% DOPO had a highest limited oxygen index (LOI) value of 29.5% and reached the V‐0 rating of UL‐94 test. The cone calorimeter tests exhibited that DOPO had a better synergistic effect with g‐C3N4 than MPP to improve flame retardancy of PLA. The peak heat release rate (pHRR) and total heat release (THR) of PLA composites containing 10 wt% DOPO could be reduced by 25.2% and 23.6%, respectively, as compared with those of pure PLA. The presence of rich phosphorus element and aromatic groups in DOPO contributed to obtain continuous compact char layer and increase the graphitization level of char residues, thereby, resulting in improving the flame retardancy of PLA together with g‐C3N4. In addition, the incorporation of DOPO can serve as a plasticizer to reduce the complex viscosity, improving the processability of PLA composites. [ABSTRACT FROM AUTHOR]

Antibacterial surfaces in healthcare settings are an important tool for combating the increasing threat of antibacterial drug resistance, which the global Covid-19 pandemic has further exacerbated. Herein, we report a new method to achieve dual antibacterial and flame retardant functionalities in flexible polyurethane foam (PUF) by synthesising a multifunctional coating using a layer-by-layer assembly technique. The coating consists of Ti 3 C 2 nanosheets and chitosan as the flame retardant and metal particles (copper or silver) for the antibacterial property. Results show that the multilayer Ti 3 C 2 /CH/Ag coating possesses excellent antibacterial performance with reductions of 99.97% in gram-negative bacteria (P. aeruginosa) and 88.9% in gram-positive bacteria (S. aureus) compared with the unmodified counterpart. Compared with the pristine PUF, the multifunctional coating yielded 66.3% reductions in the PHRR, and demonstrated outstanding smoke suppression performance with a PSPR reduction of 51.6% and a TSR decline of 65.5%. Moreover, Raman spectroscopy revealed an increased graphitisation level in the residual char of the coated foam, indicating the coating's remarkable charring performance. This exceptional multifunctional performance endows the coating technology with a great potential for eradicating the fire risks of antibacterial surfaces in healthcare settings and providing furniture, interior walls and building panels with antibacterial properties. [Display omitted] • Ti 3 C 2 /chitosan and antimicrobial particles coated PUF is prepared via LbL assembly. • Dual functional PUF manifests excellent flame retardancy with 66.4% PHRR reduction. • Antimicrobial coating of silver ions decreases 99.97% of gram-negative bacteria. • Ti 3 C 2 and antimicrobial coatings synergistically enhance PUF charring performance. • A dual functional flame-retardant anti-microbial soft-furnishing foam is achieved. [ABSTRACT FROM AUTHOR]

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

• A functionalized POSS-Ti 3 C 2 T x has been prepared via a facile surface-manipulation approach. • Upon addition of 2 wt% of POSS-Ti 3 C 2 T x , a 39.1 % reduction in the peak heat release rate of PS is obtained. • A 54.4 % reduction in the peak CO production rate of PS is achieved. • The initial temperatures of PS in nitrogen and air also increase by 22 °C and 39 °C, respectively. • The good fire safety is due to the adsorption, catalytic and barrier effects of POSS-Ti 3 C 2 T x. High-performance MXene-based polymer nanocomposites are highly desirable for diverse industry applications due to their exceptional mechanical, thermal and other properties. Nevertheless, it remains an intractable challenge to create flame retardant polymer/MXene nanocomposites due to the difficulty to achieve uniform dispersion of MXenes. Here, we reported a facile strategy for the surface manipulation of two-dimensional titanium carbide nanosheets (Ti 3 C 2 T x) with 3-aminopropylheptaisobutyl-polyhedral oligomeric silsesquioxane (AP-POSS) (POSS-Ti 3 C 2 T x) through electrostatic interactions. The POSS-Ti 3 C 2 T x is steadily dispersed in many polar solvents. Upon incorporated into polystyrene (PS), the combined effect of AP-POSS and MXene makes the resultant PS nanocomposites exhibit significantly improved thermal and thermoxidative stability, e.g. 22 °C and 39 °C increases in the temperature at 5 wt% mass loss under nitrogen and air, respectively. Meanwhile, a 39.1 % reduction in the peak heat release rate, a respective 54.4 % and 35.6 % reduction in the peak CO production rate and the peak CO 2 production rate was achieved, which are superior to those of its own and previous counterparts. This outstanding fire safety is attributed to the combination of adsorption, catalytic and barrier effects of POSS-Ti 3 C 2 T x. Hence, as-designed functionalized MXenes can be effectively applied in PS to formulate multifunctional polymer nanocomposites attractive for wide potential applications. [ABSTRACT FROM AUTHOR]

In recent years, the utilisation of bio-based materials in flame retardants (FRs) has been widely advocated due to significant recyclability, flame retardancy and cost-effectiveness. For example, carbon derived from peanut shells (CPS) with sheet-like structures are natural FRs with rich carbon sources for epoxy resins (EP). In this study, we hybridised CPS with black phosphorous (BP) via the ball milling method and embedded it in EP to exploit their synergistic effects. CPS enhances the formation of a durable char layer, complemented by BP's dual action in scavenging radicals in the gas phase and promoting char formation in the condensed phase. The modified EP (EP/BP/CPS) has offered excellent flame resistance towards pinewood that 3 wt% addition of EP/BP/CPS can significantly reduce the peak heat release rate (pHRR) and total heat release (THR) and total smoke reduction (TSR) by 45 %, 14 %, and 28 % compared to pure EP coated pinewood. Importantly, we proposed a numerical framework that can be fully utilised to integrate the fire field model, reconstruct the fire scene and predict the fire development stages by coupling pyrolysis kinetics with computational fluid dynamics (CFD). The combustion behaviour of pinewood coated with EP/BP/CPS was characterised. In particular, the burning characteristics such as pHRR, time to ignite (TTI) and burning duration were well-predicted. This work has proven that the hybridised EP/BP/CPS is an effective and sustainable FR coating for timber structure buildings, while its combustion behaviour can be numerically characterised for large-scale fire safety assessment. • Novel bio-based FR is synthesised using carbon derived from peanut shells and black phosphorus. • The EP embedded with FR suppressed pHRR, THR and TSR by 44.9 %, 14.0 %, and 27.6 %. • CFD pyrolysis model was developed to predict FR-coated materials. • The numerical model simulated the flaming behaviour of FR-coated materials accurately on pHRR. [ABSTRACT FROM AUTHOR]

Fabricating high-performance MXene-based polymer nanocomposites is a huge challenge because of the poor dispersion and interfacial interaction of MXene nanosheets in the polymer matrix. To address the issue, MXene nanosheets were successfully exfoliated and subsequently modified by long-chain cationic agents with different chain lengths, i.e., decyltrimethylammonium bromide (DTAB), octadecyltrimethylammonium bromide (OTAB), and dihexadecyldimethylammonium bromide (DDAB). With the long-chain groups on their surface, modified Ti3C2 (MXene) nanosheets were well dispersed in N,N-dimethylformamide (DMF), resulting in the formation of uniform dispersion and strong interfacial adhesion within a polystyrene (PS) matrix. The thermal stability properties of cationic modified Ti3C2/PS nanocomposites were improved considerably with the temperatures at 5% weight loss increasing by 20 °C for DTAB-Ti3C2/PS, 25 °C for OTAB-Ti3C2/PS and 23 °C for DDAB-Ti3C2/PS, respectively. The modified MXene nanosheets also enhanced the flame-retardant properties of PS. Compared to neat PS, the peak heat release rate (PHRR) was reduced by approximately 26.4%, 21.5% and 20.8% for PS/OTAB-Ti3C2, PS/DDAB-Ti3C2 and PS/DTAB-Ti3C2, respectively. Significant reductions in CO and CO2 productions were also obtained in the cone calorimeter test and generally lower pyrolysis volatile products were recorded by PS/OTAB-Ti3C2 compared to pristine PS. These property enhancements of PS nanocomposites are attributed to the superior dispersion, catalytic and barrier effects of Ti3C2 nanosheets. [ABSTRACT FROM AUTHOR]

In this article, a novel strategy has been proposed for the preparation of polyurethane/alumina aerogel (FPU/Alag) composites with homogeneous dispersion of alumina aerogel. The FPU/Alag composites have been prepared via immersing FPU foams into alumina sols followed by a freeze-drying method. Fire safety performance of the FPU composites with various Alag compositions in terms of thermal properties and flammability performance were evaluated. The composites demonstrated an earlier thermal degradation but higher thermal stability with increasing temperature and greater char yields than pure FPU. Total heat and smoke release, and rate of smoke emission of the FPU/Alag composites were found to be greatly reduced in comparison with those of FPU. Morphology and thermal conductivity ( κ ) properties of FPU/Alag composites and their corresponding residual char were investigated. The κ values of the composites were measured to be higher than that of FPU due to the accumulation of alumina flakes on the cell-walls of FPU. In contrast, the κ values of the char were lower than that of the calcinated alumina aerogel (C-Alag) counterpart, due to the formation of side by side, partially-opened compartments isolated by alumina flakes. Nitrogen adsorption analysis showed that C-Alag had a specific surface area of 211.5 m 2 /g and mesoporous volume of 0.28 cm 3 /g. The remarkable improvement in fire safety of FPU foams with the addition of Alag could be attributed to the combined effects of thermal-insulating, retention and adsorption of C-Alag that was in-situ formed inside FPU matrix during the combustion process. [ABSTRACT FROM AUTHOR]

Carbon derived from peanut shell (CPS) with 2D structure has been proved to own sufficient thermal stability and is a promising flame retardant (FR) additive for EP in our previous work. To further explore the feasibility of implementing CPS into the intumescent fire retardant (IFR) system, a novel green IFR system was first proposed in this study. Environmental-friendly chemicals phytic acid (PA) and melamine were self-assembled on the carbon's surface through the hydrothermal method. Cone calorimeter test results reveal that 3 wt% loading of the proposed IFR reduces total heat release (THR) by 38.8 % and total smoke release (TSR) by 31.3 %. What's more, the char residue grows significantly, from 5.8 % to 14.3 %. The fire retardancy mechanism was also studied. For the gaseous phase, the release of inert gas products from melamine prevents volatile decomposition products into the combustion zone. In terms of the solid phase, a synergistic barrier effect is provided by 2D structure of peanut shell derived carbon and the intumescent residue with a compact exterior layer, protecting the underlying polymer matrix. This green IFR system provides better fire performance, which can be a potential alternative for EP and extend its application. • A novel bio-inspired IFR system was firstly constructed. • Phytic acid and melamine were successfully self-assembled on peanut shell derived carbon. • 3 wt% loading of the proposed IFR reduced THR and TSP by 38.8 % and 31.3 %, respectively. • The synergistic physical barrier effect was provided by 2D structure carbon and the intumescent effect for char formation. [ABSTRACT FROM AUTHOR]

• Waste heat from HEVs is applied to the ejector battery thermal management system. • Accurate prediction of complex flow behaviors in ejector by the condensation model. • Ejector's COP and ER shows inverse trend with increasing inlet superheating. • Ejector's performance reaches maximum with an increase of 11 K inlet superheating. Thermal management system generally ensures the safe operating conditions and heat resilience of battery packs in hybrid electric vehicles (HEVs). The current study raised a novel approach to reduce fire risks related to HEVs through a novel battery thermal management system powered by low-grade combustion waste heat running on steam ejectors for the first time. In this paper, an ejector operating at a low temperature under 100 °C for HEV's battery thermal management system is proposed and investigated. An in-house wet-steam model considering the condensation effect has been developed to characterise the ejector's internal flow structure and further analyse its feasibility as a thermal management system. The results show that the model considering the condensation process is more feasible in evaluating the performance of the steam ejector than the dry gas assumption. To improve the performance of the proposed ejector battery thermal management system, the effect of superheating of primary steam has been investigated. The results showed that an optimum point exists with 11 K superheating between improvement of entrainment ratio, the system's coefficient of performance and the power efficiency for the current case. The entrainment ratio at that point reaches around 0.45, while the coefficient of performance reaches 0.225. [Display omitted] [ABSTRACT FROM AUTHOR]

As one of the lightest materials in the world, aerogels are widely adapted in heat insulation, electromagnetic interference shielding, oil-water separation, etc. Nevertheless, owing to their high flammability, the application scenarios of aerogels in extreme environments are severely limited. To reduce the intrinsic inflammable properties of aerogels, nanomaterials are commonly incorporated as additives to fabricate flame retardant nanocomposites, which creates a barrier effect and catalytic carbonization capacity. Nonetheless, up-to-date, the multifunctional development of these aerogels has been barely explored. Herein, we systematically summarized the recent progress on multifunctional nanocomposite aerogels based on various nanomaterials with different dimensions. The preparation approaches and performance evaluation of the most common types of aerogels were depicted in detail. Moreover, the investigation of multifunctional aerogels and their prospects were demonstrated, and in-depth discussed. This review work aims to deliver an insight towards further directions and developments of multi-functional flame-retardant aerogels for extended applications in extreme environments. [Display omitted] • The recent progress on flame retardant nanocomposite aerogels was reviewed. • The preparation approaches of the nanocomposite aerogels were described. • The proprieties and application of the flame retardant aerogels were illustrated. • The prospects of the flame retardant nanocomposite aerogels were depicted. [ABSTRACT FROM AUTHOR]

Small-scale cone calorimeter tests are commonly used to evaluate the flammability properties of building materials used in cladding systems. However, the combined effect of aluminium composite cladding panels (ACPs) and insulations used in cladding systems has rarely been investigated in the field of small-scale fire assessment. This could be due to a lack of device adaptation for testing multi-component materials, as well as difficulties in translating the results to real-world scenarios. In this study, an alternative fire performance screening method based on a cone calorimeter is developed to evaluate the flammability properties of the cladding system. Two types of assemblies were tested to highlight the interaction between panel and insulation in cladding systems: i) layer-by-layer and ii) side-by-side. The results showed that the more flammable insulation accelerated the global combustion kinetics in side-by-side assemblies. The presence of insulation to the back of the cladding panel in layer-by-layer assemblies caused a thermal thickening, which slowed the combustion of the front cladding panel. Finally, acceptance criteria are developed to assess the fire risk of cladding systems. • Combined fire performance of cladding panel with insulation is investigated. • Alternative screening method is developed for cladding system using cone calorimeter. • Flammable panels and insulations are acting as an accelerator during cladding fire. • A new risk assessment criterion is developed for flammable cladding system. [ABSTRACT FROM AUTHOR]

The fire behaviour of radiata pine timber, treated with intumescent coatings and exposed to heat flux conditions equivalent to a high-risk bushfire attack level (BAL) is investigated. The experiment is designed for coated timber exposed to bushfire attack levels greater than 19 kW/m2 and up to 29 kW/m2 (BAL-29) in accordance with AS 3959. The timber was coated with a DFT of 400 μm of the developed intumescent formulations based on expandable graphite (EG), ammonium polyphosphate (APP) and a waterborne acrylic resin with high adhesion strength. The coated timbers were tested according to AS3959, for a BAL-29 rating, using a cone calorimeter at 25 kW/m2 for 10 min. Most of the coated samples reported a substantial reduction in the peak heat release rate (p-HRR) and average HRR with values not greater than 100 kW/m2 and 60 kW/m2, respectively. These results satisfy the requirements for bushfire-resistant timber at BAL-29 rating. Formulation 4 (F4), with EG:APP ratio of 3:1 and resin content of 45 wt% was identified as the most cost-effective formulation. Coatings with high loading of EG and APP provided the best fire protection to the timber substrate, however, a larger char with a less compact structure is formed. • High adhesion strength was reported by the waterborne acrylic resin. • A cost-effective coating with 3:1 EG:APP ratio and 45 wt% resin was identified. • A substantial reduction in p-HRR was reported by the coated timber. • Key factors affecting the performance of the intumescent coating were identified. [ABSTRACT FROM AUTHOR]

• Cationic modifiers decorated Ti 3 C 2 ultra-thin nanosheets were prepared. • TPU/modified Ti 3 C 2 nanocomposites were fabricated via solution blending. • TPU/modified Ti 3 C 2 nanocomposites showed excellent fire safety properties. Thermoplastic polyurethane (TPU) has broad applications as lightweight materials due to its multiple advantages and unique properties. Nevertheless, toxicity emission under fire conditions remains a major concern, particularly in building fire scenarios. To circumvent the problem, it is imperative that an effective flame retardant is sought to suppress the flame and release of combustion/smoke products whilst maintaining the favorable material properties of TPU. In the current work, a simple method is proposed for the preparation and utilization of cetyltrimethyl ammonium bromide (CTAB) and tetrabutyl phosphine chloride (TBPC) modified Ti 3 C 2 (MXene) ultra-thin nanosheets. During the cone calorimeter tests, significant reduction in peak heat release rate (51.2% and 52.2%), peak smoke production rate (57.1% and 57.4%), peak CO production (39.4% and 41.6%) and peak CO 2 production (49.7% and 51.7%) were recorded by the mere introduction of 2 wt.% CTAB-Ti 3 C 2 and TBPC-Ti 3 C 2 to TPU. These superior fire safety properties resulting from the significant reduction of the fire, smoke and toxicity hazards are attributed to the excellent dispersion, catalytic and barrier effect of Ti 3 C 2 ultra-thin nanosheets in TPU. Future applications of exfoliated MXene nanosheets as flame retardant appear to be very promising. [ABSTRACT FROM AUTHOR]

[Display omitted] • Multifunctional vanillin-based porphyrin (VPR) was designed and synthesized. • PLA/VPR biocomposites exhibited highly enhanced toughness. • PLA/VPR biocomposites showed excellent UV-resistance properties. • PLA/VPR biocomposites presented great self-extinguishing performance. To achieve high-performance polylactic acid (PLA) composites, the exploitation of multifunctional biomass additives derived from renewable resources are highly demanded. Herein, a vanillin-based porphyrin (VPR) was designed and synthesized to impart PLA with enhanced mechanical, anti-UV, and flame retardant properties. Multiple intermolecular interactions between VPR and PLA enabled significant toughening of the PLA/VPR biocomposites compared to PLA itself. The elongation at break and impact strength for PLA/3VPR were improved by 88.2 % and 104.2 %, respectively, without influence on their tensile strength. Furthermore, the PLA/VPR biocomposites exhibited improved anti-UV performance with only 1.5 % and 8.6 % decrease of the strength and elongation at break respectively after UV aging. More importantly, incorporation of only 3 wt% VPR loading within the PLA/3VPR composite allowed for excellent self-extinguishing with a UL-94 V-0 level, greatly improving the versatility of PLA composites. We envision that such bio-based PLA/VPR materials with multifunctional features will extensively broaden the usable range of PLA composites. [ABSTRACT FROM AUTHOR]

The inherent shortcomings such as flammability, brittleness, and low crystallinity limit the broad applications of poly(lactic acid) (PLA). To improve the fire resistance and mechanical properties of PLA, a chitosan-based core-shell flame retardant additive (APBA@PA@CS) was prepared for PLA via the self-assembly of interionic interactions among chitosan (CS), phytic acid (PA), and 3-aminophenyl boronic acid (APBA). The peak heat release rate (pHRR) and total heat release rate (THR) of PLA composite containing 3 wt% APBA@PA@CS decreased from 460.1 kW/m2 and 75.8 MJ/m2 to 419.0 kW/m2 and 53.1 MJ/m2, respectively. The presence of APBA@PA@CS contributed to the formation of a high-quality char layer rich in phosphorus and boron in the condensed phase and released non-flammable gases in the gas phase to hinder the exchange of heat and O 2 , thereby having a synergistic flame retardant effect. Meanwhile, the tensile strength, elongation at break, impact strength, and crystallinity of PLA/APBA@PA@CS were increased by 3.7 %, 17.4 %, 5.3 %, and 55.2 %, respectively. This study provides a feasible route to construct a chitosan-based N/B/P tri-element hybrid to improve the fire safety performance and mechanical properties of PLA biocomposites. [Display omitted] • Biobased flame retardant (APBA@PA@CS) was prepared by interionic self-assembly. • Char residues rich in N/P/B elements had better flame retardant effects. • The high interface compatibility of APBA@PA@CS enhanced the mechanical properties. [ABSTRACT FROM AUTHOR]

[Display omitted] • Zinc porphyrin complex was synthesized via Alder-Longo and complexation. • PS/zinc porphyrin showed outstanding thermal stability and UV-resistance. • PS/zinc porphyrin exhibited improved mechanically strength and toughness. • PS/zinc porphyrin demonstrated enhanced fire safety properties. Polystyrene (PS) is one of the most commonly used general plastics. Nonetheless, PS is greatly limited by its inherent disadvantages such as high flammability, low stability and brittleness. To address these issues, 5,10,15,20-tetrakis(4-bromophenyl) porphyrin (TBPP) and zinc 5,10,15,20-tetrakis(4-bromophenyl) porphyrin (Zn-TBPP) were synthesized as multifunctional additives for fabricating high-performance PS composites. Both TBPP and Zn-TBPP showed high thermal stability and excellent UV-absorption, which significantly enhanced the UV-resistance of PS without sacrificing mechanical property after 100 h UV-aging. The addition of 5 wt% Zn-TBPP led to the remarkable improvement of thermal stability of PS (41 °C and 79 °C increases in the thermal decomposition temperature at 5 wt% mass loss under N 2 and air, respectively). Moreover, contributed from the strong π-π interaction between porphyrins and PS chains, the mechanical properties of PS were enhanced when 5 wt% Zn-TBPP was added into PS (11.1% increase in tensile strength and 96.6% increase in elongation at break). Furthermore, compared to TBPP/PS, Zn-TBPP/PS exhibited an improved flame retardant performance with 26.0%, 14.4% and 31.5% reduction of peak heat release rate, peak CO and CO 2 production respectively, indicating the catalytic flame retardant effect from zinc element. [ABSTRACT FROM AUTHOR]

Acrylonitrile-butadiene-styrene (ABS) resin is a commonly used engineering thermoplastic. Nevertheless, the fire toxicity hazards (HCN, NO x , NH 3 and CO) generated from the combustion of ABS remains a major concern, especially in building fire scenarios. To address this issue, boron dipyrromethene (BODIPY) modified MXene (Ti 3 C 2 T x) nanosheets were prepared and utilized as a flame retardant for ABS. The loading of 0.5 wt% BODIPY-MXene resulted in the uniform dispersion in ABS. Accordingly, the tensile strength, Young's modulus and elongation at break of ABS/BODIPY-MXene0.5 were improved by 27.8%, 18.6% and 17.9% respectively compared to neat ABS, suggesting the enhanced mechanical properties. The limiting oxygen index (LOI) value was increased from 19.5% for neat ABS to 21.5% and 23.5% for ABS/BODIPY-MXene0.5 and ABS/BODIPY-MXene2.0 benefitted from the rapid carbonization. The cone calorimeter coupled with FTIR analysis showed that the reductions in peak heat release rate (−24.5%), peak smoke production rate (−18.4%), peak concentration of HCN (−33.5%), NO (−22.0%), N 2 O (−46.6%), NH 3 (−76.0%) and CO (−28.8%) were achieved by incorporating 0.5 wt% BODIPY-MXene to ABS in comparison with pure ABS. The improved fire safety properties were primarily attributed to the excellent barrier, free radical capture, and catalytic carbonization effect of BODIPY-MXene nanosheets within ABS matrix. [Display omitted] • BODIPY-MXene nanosheets were fabricated based on electrostatic interaction. • ABS/BODIPY-MXene nanocomposites were prepared via solution blending. • ABS/BODIPY-MXene exhibited improved mechanical performance. • ABS/BODIPY-MXene showed enhanced fire safety properties. [ABSTRACT FROM AUTHOR]

A bio-flame retardant filler was synthesized via the self-polymerization of dopamine hydrochloride in alkaline condition, yielding nano-sized polydopamine (nano-PDA) particles ranging between 50 and 100 nm in diameters. Adding a small amount (2 wt%) of the nano-PDA particles into an epoxy can remarkably reduce the value of peak heat release rate by 53.6%, exceeding the performance aluminum trihydroxide (ATH) particles at 10 wt%. The significant improvement in flame retardancy at a relatively low loading of PDA has been found to originate from several key mechanisms including radical scavenging, higher char yield, and production of CO 2. Furthermore, the addition of nano-PDA in the epoxy resin increased the tensile strength by ~6%. In contrast, the addition of common flame retardant, such as ATH, to achieve the same increase in flame retardancy of epoxy would reduce the tensile strength by 22%. This improvement in mechanical properties is attributed to the better bonding between PDA particles with epoxy than ATH with epoxy. [ABSTRACT FROM AUTHOR]