Effect of para-substituent on copolymerization and thermal degradation kinetics of styrene copolymers composed with maleic anhydride derivative

The investigation of the polymerization kinetics and thermal degradation kinetics of maleic anhydride copolymers is of significant reference value for the synthesis of multifunctional and high-performance maleic anhydride-based copolymers and their applications in different fields. In this study, anhydride (MAH) derived styrene copolymers, namely Poly(N-phenylmaleimide-alt-styrene) (PNS), Poly(N-(4-carboxyphenyl)maleimide-alt-styrene) (PCS), andpoly(N-fluorine-phenylmaleimide-alt-styrene) (PFS), were prepared using a solution copolymerization method. The copolymerization kinetics and thermal degradation kinetics of MAH derived styrene copolymers were investigated using nuclear magnetic resonance (NMR) and thermogravimetric analysis (TGA), as well as the Arrhenius equation and Kim-Park method. The study revealed that the incorporation of carboxyl and fluorine groups had varying degrees of influence on maleic anhydride-styrene copolymers. The copolymerization rate constant (K value) followed the order PNS>PCS>PFS, while the copolymerization activation energy (E_a) followed the order PNS<PFS<PCS. Moreover, the thermal degradation activation energy (E_a′) followed the order PNS<PNS<PFS, indicating that PFS exhibited easier polymerization and the fluorine group significantly enhanced the thermal stability of the maleic anhydride-styrene copolymers.