PB-g-PMMA核壳粒子的合成及其在PVC中的分散

Synthesis of PB-g-PMMA Core/Shell Copolymer and Its Dispersion in PVC

聚丁二烯 (PB)橡胶粒子与聚氯乙烯 (PVC)不相容。采用乳液聚合手段 ,在聚丁二烯乳胶粒表层接枝与聚氯乙烯相容的聚甲基丙烯酸甲酯 (PMMA)充当增容剂制备了聚丁二烯接枝聚甲基丙烯酸甲酯 (PB g PMMA ,MB)核壳粒子。用熔融共混法制备了PVC/MB共混物。SEM照片表明 ,这种核壳结构的粒子在聚氯乙烯中的分散情况随着核壳比的不同而改变 ,当核壳质量比小于 93/7时能够完全均匀地分散在PVC基体中 ,核壳质量比大于 94/6时根本不能分散在PVC基体中 ,核壳质量比为 93/7是粒子能否分散开的转折点。共混物的力学性能数据表明 ,当MB加入量改变时 ,共混物也存在脆韧转变点 ,但受MB粒子的核壳比影响。

Polybutadiene (PB) is incompatible with poly(vinyl chloride)(PVC).Poly(methyl methacrylate)(PMMA) was grafted on PB latex particles to prepare PB-g-PMMA core/shell particles by emulsion polymerization.PVC/MB blends were prepared by melting blend. SEM photos indicated that MB particles′ dispersion had changed with the ratio of PB core to PMMA shell weight (CS ratio).The MB particles can be finely dispersed in PVC matrix when the CS ratio from 91/9 to 93/7,whereas the dispersion became worse when CS ratio from 94/6 to 100/0(pure PB).The CS ratio 93/7 is a changing point whether the particles can be dispersed.The mechanical properties verified that the blend also had a point of brittle-ductile transition with the contents of MB changed,but it could be affected by the CS ratio.