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Lightweight wood‐plastic composites (WPC) are made from expandable polystyrene and wood particle using a mold foaming technique, and their fire resistance is improved with the addition of melamine phosphate (MPP) and aluminum hypophosphite (AHP). Flame retardancy is characterized and shown to be significantly enhanced on limiting oxygen index (LOI), vertical burning test (UL‐94), and cone calorimetry tests. The fire behavior investigation indicates that the LOI value of WPC/12MPP/3AHP sample can reach 33.5% and UL‐94 rating was V‐0. The total heat release, total smoke production, peak of smoke production rate and peak of heat release rate of WPC/15MPP are reduced by 23.2%, 47.5%, 28.6% and 17.3%, respectively, compare with the pure one. Mechanical properties characterization of composites also reveals that MPP/AHP has a positive influence on the impact strength, modulus of elasticity and modulus of rupture. [ABSTRACT FROM AUTHOR]

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

The preparation of wood products with mechanical reinforcement, flame retardancy, and water resistance is still a problem to be solved. In this work, carbonated apatite (CAp) was bio-mineralized in wood vessel by the method of gradient impregnation. The CAp@wood75G sample with the weight gain of 75 wt% showed the greatest bending strength and compressive strength due to the formation of organic–inorganic composites. With the high bending strength and compressive strength, the CAp@wood75G sample exhibited elevated limiting oxygen index (LOI) of 60.4% and self-extinguished immediately in the vertical burning test. In cone calorimetry test, the peak of heat release rate and total heat release for CAp@wood75G sample were lessened by 68.2 and 53.1% respectively, compared with that of natural wood sample. Furthermore, the LOI of CAp@wood75G with self-extinguishment was still as high as 38.4% even after immersed in water for 24 h. Furthermore, the flame retardant mechanism was explored and generalized. The CAp was decomposed to produced CO2 and H2O to dilute the combustible gases in the air, and catalyzed wood to form the barrier of heat and oxygen during burning. Moreover, CAp produced inorganic salts which played the protective layer role. To conclude, this efficient processing method by bioinspired mineralization was eco-friendly and effective. [ABSTRACT FROM AUTHOR]

The incorporation of biological resources for developing flame retardant is a promising approach to fabricate durable flame retardant fabrics. Herein, a novel bio-based flame retardant ammonium salt of taurine phosphonate (PTau) was successfully synthesized from taurine and grafted onto the nylon-cotton (NYCO) blend fabrics by covalent bonds. Both the flame retardancy and washing durability of PTau treated NYCO fabrics were improved significantly. The limiting oxygen index (LOI) value of PTau-NYCO fabric was increased from 18.5 % to 36.7 % and the damaged length was reduced from 30.0 cm to 5.6 cm during the vertical burning test. The flame retardancy of PTau-NYCO fabric was well preserved with the LOI value of 29.2 % after 40 laundering cycles. Cone calorimeter test indicated that the PTau-NYCO fabric decreased the peak heat release rate from 207.7 kW/m2 to 77.5 kW/m2, and the total heat release rate from 10.5 MJ/m2 to 5.6 MJ/m2, respectively, compared with that of the control NYCO fabric. Thermogravimetric analysis test showed that the char formation ability was improved for PTau-NYCO fabric with the char residue of 37.2 wt% at 800 °C. The flame retardant mechanism showed that PTau was beneficial to form the char layer and generate nonflammable gases. In general, this work proposes a feasible method to produce durable flame retardant NYCO fabrics by using taurine derivatives. [Display omitted] • The bioactive substance of taurine is an eco-friendly and sustainable resource. • Treated nylon-cotton blend fabrics showed improved flame retardancy and excellent washing durability. • The application of taurine provided an effective strategy to reduce the fire hazards of fabrics. [ABSTRACT FROM AUTHOR]

• A 3D boron nitride skeleton was fabricated by the ice template method. • The thick skeleton layer provides a more efficient heat transfer path. • The synergistic flame retardant mechanism of boron nitride and ammonium polyphosphate was revealed. • The char residue left in the combustion can support weights more than 1100 times of its own mass. Epoxy (EP) is widely used in the field of high-speed communication and microelectronics. However, its poor thermal conductivity and high flammability bury the hidden danger of fire accident. In this work, the hexagonal born nitride (h-BN) combined with ammonium polyphosphate (APP) constructs a three-dimensional skeleton (3D-BN) via bidirectional freezing technology. The 3D-BN skeleton is immersed into the EP matrix to obtain the EP/3D-BN composite, which is endowed with high thermal conductivity and flame retardancy. When the loading of hexagonal born nitride (h-BN) is 9.1 vol%, the thermal conductivity of EP/3D-BN 3 composite reaches 1.67 W m−1 K−1, which is increased by 944 % compared with that of the control EP. The peak heat release rate (PHRR) and total heat release (THR) of EP/3D-BN 3 are significantly reduced by 54 % and 34 % respectively. This EP/3D-BN composite provides potential applications toward the industrial production for microelectronic devices. In this work, the hexagonal born nitride (h-BN) combined with ammonium polyphosphate (APP) constructs a three-dimensional scaffold (3D-BN) via bidirectional freezing technology. The 3D-BN scaffold is immersed into the epoxy (EP) matrix to obtain the EP/3D-BN composite, which is endowed with high thermal conductivity and flame retardancy. [Display omitted] [ABSTRACT FROM AUTHOR]

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

It is still a big challenge for textile industry in improving fire resistance and reducing melt dripping with minimal loss on the physical properties of polyethylene terephthalate (PET) fabrics. In this work, a highly-effective hyperbranched flame retardant (DT) was first synthesized by ester exchange without using any organic solvent. Then, the DT foam was prepared and blade coated on PET fabric to improve the fire performance. The prepared PET fabric with only 2.7% weight gain of DT was self-extinguished and did not produce any molten dripping during the vertical flammable test. The peak heat release rate and total heat release of the PET fabric sample with 19.4% DT were decreased by 42.0% and 57.1%, respectively compared with that of the control PET. Besides, the as-prepared PET fabric sample showed better physical properties such as breaking strength, vapor permeability, air permeability, antistatic property, and softness than the control PET fabric sample. The DT foam finishing process did not involve any organic solvent and consumed less water and energy compared with conventional fabric treatments. It is expected that this work provides a facile and eco-friendly strategy for fabricating flame retardant PET fabric with excellent comprehensive performances. [Display omitted] • A hyperbranched flame retardant (DT) was synthesized by a solvent-free approach. • Flame retardant PET fabrics were prepared by sustainable foam finishing. • The PET fabric with 2.7% DT was self-extinguished and free of molten drops. • The treated PET fabric showed excellent physical properties. [ABSTRACT FROM AUTHOR]

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

• Phosphorylated histidine-amino triazine-diaminopropane (PHTD) copolymer was synthesized and used as bifunctional additives of flame retardant and binder. • PHTD can improve the flame retardancy and smoke suppression of EPS foams significantly. • The hard shell formed by PHTD can improve the compressive strengths of EPS foams. A novel intumescent flame retardant, phosphorylated histidine-amino triazine-diaminopropane (PHTD) was synthesized and utilized as both a flame retardant and a binder addition. Flame retardant expanded polystyrene (EPS) foams containing PHTD was successfully prepared by coating method. The limited oxygen index (LOI) and vertical burning (UL-94) tests were used to determine the flammability of EPS/PHTD composite foams, and an apparent flame retardant effect could be obtained with up to 28.8% LOI value and UL-94 V-0 rating when 41.9 wt.% PHTD was added. The cone calorimetric test results showed that the treat EPS sample showed significantly depressed peak heat release rate (pHRR) by 74.9% and peak smoke production rate (pSPR) by 77.3%. Additionally, the flame retardant could be evenly coated on the surface of EPS beads. Even though part of the foam was damaged, it could still keep good flame retardant performance. Furthermore, the thermal conductivity of coated foam was not affected and remained at a comparatively low level, and the compressive strength was increased by 20.0%. [ABSTRACT FROM AUTHOR]