PB-g-SAN弹性体的合成及其对SAN树脂的增韧

Synthesis of PB-g-SAN Elastomer and Its Toughening Behavior for SAN Resins

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苯乙烯(St)和丙烯腈(AN)合成了一系列PB质量分数为40%的PB g SAN弹性体·研究了共聚单体中叔 十二烷基硫醇(TDDM)质量分数对SAN共聚物接枝行为、弹性体粒子结构及其动态力学性能的影响·结果发现,随着单体中TDDM质量分数的增加,SAN在PB上的接枝率和接枝效率降低,弹性体粒子中SAN包容结构的尺寸增大,在低温区的动态剪切模量下降·将其与SAN树脂共混后发现在共聚单体中引入TDDM后提高了弹性体粒子的增韧效率·

A series of PB-g-SAN elastomers in which the polybutadiene(PB) content is 40% were synthesized using seed emulsion polymerization technique to graft-copolymerize styrene and acrylonitrile onto PB latex rubber particles. The effects of tert-dodecyl mercaptan(TDDM) content in monomer mixture on the grafting behavior of styrene-acrylonitrile(SAN) copolymers and the morphology and dynamic mechanical properties of elastomers were studied. It was found that the grafting degree and efficiency of SAN copolymer decrease and the size of SAN glassy sub-inclusions distributed in PB particles increases but the low temperature dynamic shear modulus of elastomer decreases with increasing TDDM content. In a series of SAN resins blended with the elastomers particles, the increase in toughness of the blends is found more efficient when introducing TDDM into monomer mixture in the process of PB-g-SAN synthesis.