PVC/α-MSAN/ASA共混物的结构与性能研究

Study on Structure and Properties of PVC/α-MSAN/ASA Blends

采用乳液聚合技术合成了一系列不同核壳比的丙烯酸丁酯-苯乙烯-丙烯腈接枝共聚物(ASA)和组成为69/31的α-甲基苯乙烯-丙烯腈共聚物(α-MSAN)。将ASA接枝共聚物与聚氯乙烯(PVC)和α-MSAN熔融共混制备了PVC/α-MSAN/ASA共混物,利用扫描电子显微镜(SEM)和差示扫描量热仪(DSC)对该共混体系的性能与形态进行了表征。结果表明:随着体系中橡胶含量的增加,PVC/α-MSAN/ASA共混物的冲击强度先增大后减小,拉伸强度则逐渐降低,其中橡胶含量为15%的共混物具有较高的韧性;当ASA接枝共聚物的核壳比逐渐增大时,共混物的冲击强度先增大后减小,而拉伸强度基本不变;此外,共混试样的断面形态与其力学性能相符。

A series of acrylate-styrene-acrylonitrile graft copolymers（ASA） with the different core/shell ratios and α-methyl styrene-acrylonitrile copolymer（α-MSAN） were synthesized by emulsion polymerization method. Then the polyvinyl chloride（PVC）/α-MSAN/ASA blends were successfully prepared by blending ASA with PVC and α-MSAN. The mechanical properties and morphology of the blends were investigated by scanning electron microscope（SEM） and differential scanning calorimetry（DSC）. The results show that： with the increase of rubber content of blends, the impact strength of the blends increases first and then decreases, while the tensile strength decreases continuously, and when the rubber content is 15%, the toughness of the blends reaches the maximum. And the impact strength of the blends increases firstly and then decreases, while the tensile strength remains unchanged with the increasing core/shell ratio of ASA. Moreover, the fracture surface morphology of blends is in accordance with the mechanical properties.