偏氯乙烯-氯乙烯悬浮共聚物的结晶与熔融性能

CRYSTALLINE AND MELTING PROPERTIES OF VINYLIDENE CHLORIDE-VINYL CHLORIDE COPOLYMERS

研究了聚合温度、共聚物组成、低分子助剂用量等对偏氯乙烯 (VDC) 氯乙烯 (VC)悬浮共聚树脂的结晶度、熔融峰温度的影响 ,并用Florry的聚合物熔点降低理论预测共聚树脂熔点随共聚组成、低分子助剂用量的变化规律 ,为VDC VC悬浮共聚树脂的合成工艺条件和加工性能的改善提供理论基础 .

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 film 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.