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Plastic is a revolutionary material. However, pollution caused by plastic damages the environment, human health, and economy of different countries. It is important to find the new methods for recycling and reusing plastic materials. In this present study, plastic waste coming from high‐density polyethylene (HDPE) cups (called HDPEr in the following) are used together with virgin cork for production of composite materials. Different fractions of virgin cork with HDPEr are tested and allow to obtain successfully composite materials. The properties of HDPEr and composite are compared. The morphology of elaborated composite is studied by scanning electron microscope (SEM). The thermal properties are investigated by thermogravimetric analysis (TGA) analysis; the flammability study is performed using a cone calorimeter. Moreover, the mechanical properties of the samples stored under different conditions are studied by tensile strength experiments. The results show that the cork content has an effect on the mechanical and thermal properties. The feasibility of the composites based on cork and HDPEr wastes opens the way of reusing of these wastes. The formulation of HDPEr composites must be optimized by adding a flame retardant and a coupling agent. [ABSTRACT FROM AUTHOR]

This study aims to increase the flame retardancy of epoxy‐based composites by using various flame retardants together with colemanite filler (CLM), which is a very mineral‐rich boron type. As a flame retardant, aluminum hydroxide (Al(OH)3) and boron‐containing compounds: borax (BRX) and natural minerals (tincal (TNC) and colemanite (CLM)), as well as barium metaborate (BaMB) synthesized by us were used. Scanning electron microscopy (SEM), x‐ray powder diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), contact angle (CA), and particle size analysis were used to characterize the composites and additives. All boron compounds increased the thermal stability of the composites. Except for the ER/CLM‐BaMB composite, other composites' surface contact angles were over 90°. In terms of both combustion and thermal properties, the best CLM‐BaMB‐Al(OH)3‐TNC ratio was determined as 15:5:15:15. The tensile strength, self‐extinguishing time, estimated and experimental Limited Oxygen Index (LOI) values for this composite were determined as 96 MPa, 65 s, 29.6%, and 25%, respectively. In addition, ANOVA was applied to determine the effect of hybrid filler type and different weight ratios on the mechanical properties of composites. [ABSTRACT FROM AUTHOR]

Natural fiber composites are not suitable for use in industries due to their flammability and low thermal resistance. Inorganic metal‐based fillers are known to enhance the flammability and thermal resistance of composites, while the thermal and fire‐retardant properties of organic fillers are not commonly known. This study evaluated the mechanical, thermal, and flammability properties of Ceiba petandra fiber (CPF)‐reinforced composites, which were added with snail powder (SP). To study the thermal resistance of the composite, a dynamic mechanical analyzer (DMA) and thermogravimetric analysis (TGA) were applied. SP Filler concentration increased the composite's tensile strength and thermal resistance. DMA test results showed the same trend as the composite's density value. The flame rate parameters of the composite, including the percentage of char yield and the limitation index oxygen (LOI), rose as the SP filler increased. However, the flame rate of the composite dropped because SP filler inhibited the movement of oxygen, combustible gas, and polyester degradation products. The addition of organic fillers in natural fiber composites promises better flammability and thermal resistance. [ABSTRACT FROM AUTHOR]

Biomass aerogels have attracted wide attention due to their excellent thermal insulation properties, but their low mechanical strength and high susceptibility to combustion limit their application. To address these limitations, a novel composite aerogel was prepared by combining chitosan aerogel (CS) and hydroxyapatite nanowires (HAP) via phytic acid (PA) cross‐linking and freeze‐drying. It was found that the maximum compressive strength and modulus of CS/HAP aerogel were 1.13 and 0.67 MPa, respectively. The minimum thermal conductivity of CS/HAP(0.5) composite aerogel was 0.03921 W m−1 K−1, indicating its good thermal insulating property. Moreover, the CS/HAP composite aerogel also showed excellent flame‐retardant properties. The heat release rate (HRR) and total heat release from combustion (THR) were significantly lower than those of the CS aerogel, with values of 35.2 kW m−2 and 3.7 MJ m−2, respectively, compared to 169.6 kW m−2 and 5.4 MJ m−2. The total smoke release (TSR) was also at a low level, reaches 0.4 m2 m−2. Highlights: Propose a novel chitosan aerogel composited with inorganic nano‐reinforced HAP.High mechanical strength of CS/HAP composite aerogel are illustrated.Exhibit excellent thermal insulation performance of CS/HAP aerogel.HAP and PA largely improves the flame retardancy of the chitosan aerogel. [ABSTRACT FROM AUTHOR]

Poly(lactic acid) (PLA) is derived from crops, and has a broad application prospect in electronics and electrical, automotive industries due to its biodegradability and good physical and mechanical properties. However, PLA's flammability and serious melt dripping cannot meet the requirements of terminal products, thus limiting its application. Over the past decade, much research on flame retardant PLA has emerged. This paper reviews the development of PLA flame retardants in recent years, focusing on phosphorus‐based, phosphorus–nitrogen‐based, bio‐based, nanoparticles, intumescent flame retardants, and their combinations. Besides that, the efficiency of flame retardant and its loading on the thermal and mechanical properties of PLA is also thoroughly reviewed. Finally, the future development of flame‐retardant PLA is briefly summarized and prospected. [ABSTRACT FROM AUTHOR]

Polybutylene terephthalate (PBT) composites were prepared with 1.0 phr synthetic wollastonite nanofibers (SWN), natural wollastonite (NW) and graphene oxide (GO) to study the effect of different fillers on mechanical, thermal, tribological, and flammability properties. The properties of PBT composites are related to the size, structure, and interfacial adhesion of the fillers in PBT matrix. PBT/SWN demonstrated the highest tensile strength and Young's modulus (6% and 9% increment), followed by PBT/NW (1.3% and 7% increment) and PBT/GO (2% decrement and 4% increment). PBT/SWN gave the highest degradation temperature (409°C), followed by PBT/GO (404.7°C). The maximum enhancement in wear resistance (73%) by PBT/SWN and anti‐friction performance (26%) by PBT/GO evinced the excellent load‐bearing ability of SWN and the great lubricating effect of GO. PBT/NW had the lowest peak heat release rate, smoke, and carbon dioxide production rate. This study shows that PBT composites have great potential in different automotive applications. [ABSTRACT FROM AUTHOR]

Polythiourethane (PTU) has attracted considerable attention in engineering building materials. Here, based on phosphazene nanoparticles (PZS‐1 and PZS‐2) prepared by water‐triggered and ultrasonic self‐assembly method, phosphazene/polythiourethane (PZS/PTU) composites with excellent mechanical strength, high flame retardancy and good transparency was obtained. Then, the comprehensive properties of both composites were evaluated, where PZS‐2 endowed PTU with better overall performance. Due to the good dispersibility of PZS and its strengthed interfacial interaction with PTU matrix, both PZS significantly enhanced mechanical and thermal property of PTU, where the tensile strength and glass transition temperature of PZS/PTU composites reached to 84.34 MPa and 59.94°C respectively. More importantly, compared to pure PTU, the values of peak heat release rate (HRR), total heat release rate (THR), smoke production rate (SPR), and total smoke production (TSP) of composites were decreased by 10.5%, 13.3%, 30.6% and 18.0%, respectively. The limiting oxygen index of composites was improved to 21.39% due to the catalytic carbonization of PZS, the expanded carbon layer and the incombustible gases released during combustion. Meanwhile, the PZS/PTU composite exhibited the high refractive index of 1.6580 and good transparency (not less than 85% at 500 nm). The PZS/PTU composite was promising candidates for optical flame retardant coatings and engineering building materials. [ABSTRACT FROM AUTHOR]

With the aim to reduce the flammability of poly(lactic acid) (PLA), herein, Tris‐phosphaphenanthrene based phosphonate (DOT) originated from 10‐hydroxy‐9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO‐OH) and trihydroxymethyl aminomethane (Tris) was incorporated. Interestingly, DOT showed superior flame‐retardant efficiency for PLA, that was, PLA with 1 wt% DOT displayed a LOI value at 29.0%, about 49.0% increment as compared to virgin PLA, and passed a UL‐94V‐0 rating. Apart from the mentioned, cone calorimeter tests clearly demonstrated that DOT was beneficial for reducing the heat release in the whole combustion to some extent, for example, the peak heat release rate and the maximum average values of heat emission with a reduction of 15% and 17%, respectively. It was speculated that the improved flame retardance of PLA containing DOT was related to the melting droplet‐promotion effect and the vapor‐phase activity of DOT. Meanwhile, thermal stabilities of PLA/DOT were well maintained as compared to virgin PLA. Moreover, the existence of DOT promoted the crystallization of PLA owing to the nucleating effect of DOT. [ABSTRACT FROM AUTHOR]

Foamed plastics are increasingly employed due to the high demand in functional materials with reduced weight. Bead foams in general offer low weight and excellent thermal insulation properties combined with extremely high freedom in design. Though foams show increased risk of ignition and heightened heat release, literature on burning behavior is rather limited. Therefore, this study investigates density‐dependent burning behavior of commercial bead foams like expanded polypropylene (EPP) and expanded modified polyphenyleneether (E‐mPPE) by cone calorimetry. The results are compared to existing studies on the density‐dependent burning behavior of different foams, mainly expanded polystyrene and foamed polyurethane. The importance of density as a characteristic is highlighted by the linear dependence of total heat emission on density for all investigated polymers, making a prediction of thermal loads possible. The peak heat release rate of flame‐retarded EPP and E‐mPPE was found not to be dependent on density, indicating an increased homogeneity by addition of flame retardant. [ABSTRACT FROM AUTHOR]

The dodecyl sulfate intercalated CaMgAl‐hydrotalcites (layered double hydroxides [LDHs]) were successfully prepared by co‐precipitation method, and characterized by X‐ray diffraction analysis, infrared spectroscopy (Fourier transform infrared spectra [FT‐IR]), thermogravimetry (TG‐DTA), scanning electron microscope, and Brunner−Emmet−Teller (BET). The prepared LDHs were added to the intumescent flame retardant (IFR) polypropylene (PP) nanocomposites, and the limiting oxygen index method (LOI), vertical combustion method (UL‐94), cone calorimetry (CCT), and other test methods were used to study its thermal stability and combustion performance. The results showed that when the flame retardant was composed of 23 wt% IFR and 2 wt% O‐SDS‐LDHs, the LOI value of the material was increased to 31.5%, reaching the V‐0 level, and the flame retardant performance was significantly improved. The results also showed that there was a significant synergistic effect between IFR and O‐SDS‐LDHs, which could improve the thermal stability and graphitization degree of PP nanocomposites. In addition, the peak heat release rate, total heat release, and total smoke production of the PP/IFR/O‐SDS‐LDHs system were 177 kW/m2, 101 MJ/m2, and 15.4 m2, respectively, which were 82.2%, 51.0%, and 23.0% lower than those of pure PP, respectively. These improvements could be attributed to the presence of dense and continuous char layer formed by the synergistic effect. [ABSTRACT FROM AUTHOR]