Preparation of epoxy-functionalized acrylonitrile/(ethylene/propylene/diene mischpolymer)/ styrene (AES) copolymer (GAES) resins by high-temperature solution polymerization

In this paper, epoxy-functionalized AES resins (GAES resins) were prepared by high-temperature solution polymerization, and FTIR spectrograms demonstrated the successful grafting of styrene (St), acrylonitrile (AN), and glycidyl methacrylate (GMA) onto ethylene/propylene/diene mischpolymer (EPDM) rubbers. The influences of reaction conditions, i.e. the content of initiator and chain transfer agent, EPDM and GMA on the grafting ratio, composition of free copolymers, molecular weights and polymer dispersity index (PDI) of GAES resins were detaily investigated. The influence of GMA content on the thermal stabilities of GAES resins was also discussed. Experimental results showed that under the optimized experimental conditions, the highest grafting ratio of GAES resins reached to 39.2% and the grafting efficiency was 35.3%. Under the same reaction conditions, the molecular weights of free copolymers reached to 70,000 g mol⁻¹. The initiator had no obvious influence on the composition of free copolymers, but the component of GMA in free copolymers increased gradually with increasing content of EPDM. Thermogravimetry (TG) analysis results indicated that the incorporation of GMA decreased the thermal stabilities of GAES resins.