乙丙抗冲共聚物的分级与性能

Structure-property investigation of impact ethylene-propylene copolymer

利用升温淋洗分级技术对两种乙丙抗冲共聚物(简称试样1和试样2)进行了分级,并研究了试样及其各级分的化学组成、序列分布、结晶熔融行为和相态结构。结果表明:试样1和试样2均由乙丙无规共聚物、乙丙嵌段共聚物和丙烯均聚物组成;试样2的乙烯含量和乙丙无规共聚物含量均高于试样1,可结晶乙丙嵌段共聚物的共聚单体分布更均匀;试样2的100℃以上高温可溶级分总含量和结晶度均高于试样1;试样2中分散相——乙丙无规共聚物颗粒数更多,颗粒粒径分布较均匀;试样2表现出更好的刚韧平衡性。

Preparative temperature rising elution fractionation is applied to the physical fractionation of two impact ethylene-propylene copolymers（sample 1 ＆ sample 2）. The chemical structure, crystallization and melting behavior, phase morphology, and sequence distribution of both samples and their fractions are further observed. The results show that both samples are composed of ethylene-propylene random copolymer, ethylene-propylene block copolymer and propylene homopolymer. The content of ethylene and ethylene-propylene random copolymer in sample 2 is more than that of sample 1, and comonomer of ethylene-propylene block copolymer in sample 2 is better distributed. Sample 2 contains more fractions which can be soluble above 100 ℃ than sample 1, and the fractions in sample 2 eluted above 100 ℃ have higher crystallinity than those in sample 1. The particles of ethylene-propylene random copolymer in dispersed phase in sample 2 are more than in sample 1, and homogeneously dispersed. As a result, the sample 2 exhibits better rigidity-toughness balance.