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• Bio-based polyester polyol was obtained through one-pot esterification. • The polyol replaced polyether polyols to prepare rigid polyurethane foams. • The flame retardancy of the foam was improved while preserving mechanical properties. A bio-based polyester polyol (BP41) was synthesized through a one-pot esterification and condensation reaction involving bio-based 1,2-propanediol, trimethylolpropane, and adipic acid. The mechanical properties, thermal stability, and thermal degradation behavior of the resulting BP41-based RPUF (PRPUF) were investigated. The prepared RPUF exhibited a density of 47.69 kg/m³, and a compressive strength of approximately 217 kPa. Additionally, it displayed excellent thermal insulation properties, demonstrated by a low thermal conductivity of 0.0261 W/(m·K) and a high initial thermal degradation temperature surpassing 281 °C. Furthermore, the incorporation of 10 % dimethyl methyl phosphonate (DMMP) terminated by erythritol (FRD) into PRPUF led to a limited oxygen index (LOI) of 32.0 % and a UL 94 rating of V-0 in vertical burning tests. The peak heat release rate was reduced by 48.9 %, while the residual char was increased significantly from 6.53 % to 15.82 %. These findings emphasize the considerable potential of the demonstrated bio-based RPUF for various commercial applications. [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]

• 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]