Green and Thermostable Bio-Based Flame Retardant System: A New Strategy for Preparing Flame-Retardant Polyvinyl Alcohol Materials via Melt Processing

In recent years, with the deepening of sustainable development concepts, polyvinyl alcohol (PVA) has garnered widespread attention as a biodegradable, non-toxic material. However, its inherent flammability significantly limits its practical applications. Developing flame-retardant PVA materials suitable for melt processing while maintaining their tensile properties remains a major challenge for practical PVA applications. This study synthesized a novel, highly thermally stable, eco-friendly bio-based flame retardant, CADCM, which was incorporated into the PVA matrix via melt processing. Results indicated that with the addition of just 12.5 wt% CADCM, the PVA composite achieved a limiting oxygen index (LOI) value of 30.3% and a vertical combustion test UL-94 rating of V-0. Reductions of 66.1% in the peak heat release rate (pHRR) and 31.7% in total heat release (THR) were observed compared to PVA0. This demonstrates that the synthesized flame retardant CADCM is suitable for preparing PVA composites with excellent flame retardancy via melt processing. Regarding mechanical properties, the composite exhibited improvements of 27.4% in tensile strength and 285.2% in elastic modulus. In terms of processing performance, the processing melting temperature of the PVA composite with CADCM addition remained suitable for processing requirements, maintaining good processability. The bio-based melt-processable flame-retardant PVA composite prepared in this study provides a feasible pathway and new insights for further expanding the scope of practical application fields of PVA materials.