Hu Fa, Cheng Bo, Cong Kun, Li Dinghua, Zhang Wenchao, Qin Zhaolu, Yang Rongjie
National Engineering Research Center of Flame Retardant Materials, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China.
SINOPEC (Beijing) Research Institute of Chemical Industry Co., Ltd., Beijing 100013, China.
Polymers (Basel). 2023 Aug 5;15(15):3312. doi: 10.3390/polym15153312.
The ladder phenyl/vinyl polysilsesquioxane (PhVPOSS) was used to improve the flame-retardancy performances of ethylene-vinyl acetate copolymer (EVA)/aluminum hydroxide (ATH) composites due to the reactivity of its vinyl groups. FTIR, XPS, H NMR, and SEM-EDS data demonstrated the PhVPOSS grafting onto EVA molecular chains. The PhVPOSS improved the thermal stability of EVA/ATH composites, as shown by the thermogravimetric analysis (TGA). Furthermore, with the cone calorimeter (CONE) experiments, EVA/ATH/PhVPOSS showed better fire safety than the EVA/ATH composites, with the PHRR, PSPR, and PCOP reduced by 7.89%, 57.4%, and 90.9%, respectively. The mechanism investigations of flame retardancy revealed that the charring behaviors of the EVA/ATH/PhVPOSS composites were improved by the formation of Si-C bonds and Si-O bonds, and a more compact and denser char layer can contribute more to the barrier effect.
梯形苯基/乙烯基聚倍半硅氧烷（PhVPOSS）因其乙烯基的反应活性，被用于改善乙烯-醋酸乙烯酯共聚物（EVA）/氢氧化铝（ATH）复合材料的阻燃性能。傅里叶变换红外光谱（FTIR）、X射线光电子能谱（XPS）、核磁共振氢谱（H NMR）以及扫描电子显微镜-能谱仪（SEM-EDS）数据表明PhVPOSS接枝到了EVA分子链上。热重分析（TGA）结果显示，PhVPOSS提高了EVA/ATH复合材料的热稳定性。此外，锥形量热仪（CONE）实验表明，EVA/ATH/PhVPOSS的火灾安全性优于EVA/ATH复合材料，其热释放速率峰值（PHRR）、有效燃烧热（PSPR）和峰值一氧化碳生成量（PCOP）分别降低了7.89%、57.4%和90.9%。阻燃机理研究表明，EVA/ATH/PhVPOSS复合材料的成炭行为因形成了Si-C键和Si-O键而得到改善，更致密的炭层对阻隔效应的贡献更大。
