The vinylidene chloride(VDC)-vinyl chloride(VC) copolymer is an excellent oxygen and moisture barrier resin available today for food packaging．The copolymer is usually obtained by suspension copolymerization．VDC-VC copolymers may have troubles in fil-forming．The problem is related with the scarcity of the crystalline and melting properties for VDC-VC copolymers．In the present paper

the effects of copolymerization temperature

composition of VDC-VC copolymers and the amount of epoxidized soybean oil (ESO) on the crystallinity and melting point were investigated．It was found that there were two melting peaks of VDC-VC copolymers

and the high melting peak disappeared with increasing copolymerization temperature and VC monomer concentration．A suitable VDC-VC copolymer resin with good processing and melting properties can be obtained by temperature-raising copolymerization technology．The melting point and crystallinity of VDC-VC copolymers and high temperature peak area decreased with increasing the VC composition．The melting point of VDC-VC copolymers decreased with increasing the ESO concentration

but the area ratio of the high to low temperature peaks was not changed．With the Flory’s melting point theory

the effects of copolymer composition and ESO concentration on the decreasing of crystalline temperature were predicted．and the theoretical calculated results were in agreement with the experimental data．