均聚物PS共混对PI-PS-PLA薄膜中微纳米结构的影响

Effect of PS Blends on Microstructure of PI-PS-PLA Thin Film

将均聚物聚苯乙烯(PS)与三嵌段共聚物聚异戊二烯-聚苯乙烯-聚乳酸(PI-PS-PLA)以一定摩尔比共混,采用原子力显微镜(AFM)研究了均聚物浓度对其薄膜样品中微纳米结构的影响。结果表明:当n(PS)∶n(PI-PS-PLA)为1∶2和1∶1时,薄膜呈现出规则排列的柱状微结构,且柱状微区的尺寸较混合前的样品有所改变;当n(PS)∶n(PI-PS-PLA)为2∶1时,PS与嵌段共聚物PI-PS-PLA的分子链发生了相分离,其中均聚物PS相形成了较大尺寸的岛状微区。

Polystyrene（PS） homopolymer and polyisoprene-polystyrene-polylactide （PI-PS-PLA） triblock copolymer were blended at certain mole ratios for preparing thin films,and the microstructures of thin film samples were investigated by AFM.Results showed that when n（PS）∶n（PI-PS-PLA） was 1∶2 and 1∶1,（ordered cylinders） appeared and the dimension of the cylinders were different from that of the unblended PI-PS-PLA thin film.When n（PS）∶n（PI-PS-PLA） was 2∶1, micro-islands of PS appeared,due to the segregation of PS chain from the PI-PS-PLA molecular chain.