Green synthesis of reactive copolymers in molten ε‐caprolactam solvent and their compatibilizing effects in PA10T/PPO blends

Abstract The environmentally‐friendly preparation of compatibilizers, especially copolymers with reactive monomers, is essential for developing new polymer blends. In this study, molten ε‐caprolactam was used as a green solvent to copolymerize styrene with three types of reactive monomers, namely maleic anhydride (MAH), glycidyl methacrylate (GMA) and 3‐isopropenyl‐α,α‐dimethylbenzyl isocyanate (TMI). The pure PS and the corresponding copolymers (PSM, PSG, and PST) had relatively high yields of 97.8%, 73.7%, 93.3%, and 96.3%, respectively. Moreover, these synthesized polymers were used as compatibilizers to modify the immiscible PA10T/PPO blends. PSM and PSG showed a positive effect in improving the compatibility of PA10T/PPO blends, reducing the size of PPO domains, and improving the mechanical properties. The long‐term thermal stability of unmodified PA10T and PA10T/PPO blends was investigated. The color changes (∆E) of PA10T, PA10T/PPO blends with the addition of pure PS, PSM, PSG, and PST changed to 46.9, 44.0, 45.2, 44.2, and 45.0 after 5 days of aging. The tensile strength retentions were 24.1%, 54.7%, 63.4%, 67.6%, and 60.0%, respectively. These results suggested that the synthesized PSG and its corresponding PA10T/PPO blend had excellent properties and great potential for the development of high‐performance plastics.