Abstract: Castor oil was modified with malcic anhydride(MA)and β-hydroxycthyl acrylatc(HEA)toyield a polvmcrizablc resin(HEAMACO)，which was copolvmerized with styrene leading to a biodegradable thermosetting polymer. The effects of HEAMACO/St ratio, dosage of initiator(BPO)，and accclcrant(V，N-dimcthvl aniline) on the glass transition temperature(Tg，crosslink density, and mechanical properties of the polymer were studied. TR and mechanical properties of the polymer could be adjusted by changing the contents of styrene, BPO or accclerant. It could behave between a soft and a semi-rigid plastic with TR changed between 10一60℃.Furthermore, this polymer based on HEAMACO resin was proved to be biodegradable in soil burial.

Key words: malcic anhydride half ester, modified castor oil, crosslinl} nctworl}, mechanical property, biodegradability