PB-g-SAN接枝共聚物的接枝率对ABS树脂结构与性能的影响

采用种子乳液聚合技术在聚丁二烯(PB)乳胶粒子上接枝共聚单体苯乙烯(St)和丙烯腈(AN),通过改变PB的含量合成了一系列具有不同接枝率的PB-g-SAN接枝共聚物(即ABS接枝共聚物),将其与SAN树脂进行熔融共混制得ABS树脂,考察了ABS接枝共聚物的接枝率对ABS树脂结构和性能的影响。结果表明,SAN共聚物在PB橡胶粒子上的接枝可分为‘内接枝’和‘外接枝’,外接枝程度影响PB橡胶粒子在SAN基体中的分散,而内接枝程度显著地影响PB橡胶粒子的内部形态结构。通过抑制内接枝,可提高ABS树脂的冲击韧性和拉伸强度;提高外接枝程度可改善ABS树脂的断裂伸长率。

Effect of the Grafting Degree of PB-g-SAN Grafting Copolymer on the Property and Structure of ABS Resin

A series of polybutadiene grafting styrene-co-acrylonitrile polymer (PB-g-SAN grafting copolymers),namely ABS grafting copolymers,with different grafting degree were synthesized by grafting styrene-co-acrylonitrile onto PB rubber particles with seeded emulsion polymerization technique.ABS resins were prepared by blending these ABS grafting copolymers with styrene-co-acrylonitrile polymer (SAN resin).The influence of grafting degree of ABS grafting copolymers on the property and structure was investigated. The results show that grafting styrene-acrylonitrile onto PB rubber particles consists of inside grafting and outside grafting. Outside grafting affects dispersion of PB rubber particles in SAN matrix,while inside grafting evidently influences internal morphology of PB rubber particles. Impact resistance and tensile strength of ABS resin are improved by inhibiting inside grafting and elongation at break of ABS resin is improved by increasing outside grafting.