| Ethylene-propylene rubber-g-polystyrene (EPR-g-PS) graft polymers were prepared by coupling reaction. Firstly, the cyclohexane solution of chlorinated ethylene-propylene rubber (CEPR) was prepared under inert atmosphere. Then, living PS was prepared via living anionic polymerization, with cyclohexane as solvent, THF as dissociation agent, and butyl lithium as initiator. After polymerization for half an hour, THF was added to decrease the freezing point, and the volume of THF was equal to the sum of cyclohexane used before. At last, the cyclohexane solution of CEPR was added into living PS solution thermostated at-60℃in alcohol-liquid nitrogen bath, and the coupling reaction was carried out until the red color of PS disappeared.Using anionic polymerization technique, the molecular weight of PS was controllable with a narrow distribution. Furthermore, under low temperature, there were no side reaction during the anionic coupling reaction and no crosslinking took place, so the polymerization degree and structure of the branched-chain was controllable. |
