Preparation of microencapsulated ammonium polyphosphate and study on flame retardancy of epoxy resin composites

作者：Jie Yan, Xutao Yu, Fuxiao Wang, Chongyang Liang, Xiaoyu Wang, Haoran Zhang, Longhui Feng, Jun Xie · 发表于：High Performance Polymers · 年份：2025 · DOI：10.1177/09540083251358880 · 被引用次数：6 · 研究领域：Flame retardant materials and properties、Silicone and Siloxane Chemistry、Photopolymerization techniques and applications

To enhance the flame retardancy of epoxy resin (EP), microcapsules (SiO 2 @APP) were prepared by encapsulating ammonium polyphosphate (APP) with silicon dioxide (SiO 2 ). Subsequently, a ternary intumescent flame retardant (IFR) system of SiO 2 @APP/MCA/CaG was formulated, using SiO 2 @APP as the primary flame retardant and acid source, melamine cyanurate (MCA) as the gas source, and calcium gluconate (CaG) as the carbon source. It was then employed for the flame retardant modification of EP. The thermal stability, flame retardancy, and mechanical properties of the EP composites were investigated through thermogravimetric analysis (TG), limiting oxygen index (LOI), UL-94 vertical burning test, cone calorimeter (CONE), scanning electron microscopy (SEM), and universal material testing machine. The results indicate that the SiO 2 @APP/MCA/CaG composite flame retardant can enhance the thermal stability and carbon residue rate of EP materials. When the mass ratio of SiO 2 @APP/MCA/CaG is 4:1:1, the residual carbon rate of EP composites at 600°C is 34.8%, and it gets the highest LOI value of 40.5%, and pass a UL-94 rating of V-0. Furthermore, compared to pure EP, the total heat release (THR) and total smoke production (TSP) are reduced by 68.8% and 66.7%, respectively. SEM testing reveals that the SiO 2 @APP/MCA/CaG flame retardant system can enhance the graphitization degree of the char residue in EP materials, resulting in a more compact structure. Furthermore, mechanical testin...