多接枝共聚物相结构及相转变行为

Phase Structure and Transition Behavior of Multi-graft Copolymer

将以聚异戊二烯(PI)为主链、聚苯乙烯(PS)为支链的规整多接枝共聚物溶于一系列具有不同选择性的溶剂(1,4-二氧六环,甲苯和环已烷)中浇筑成膜。采用同步辐射小角X射线散射(SAXS)和透射电镜(TEM)对所制溶液成膜的相分离形态进行观察,发现随着所用溶剂对PS选择性的增强,所形成相分离结构的长周期逐渐减小。以环已烷和甲苯为溶剂的溶液浇铸膜相形态均为PS的柱体分散在连续的PI相中,而以1,4-二氧六环为溶剂的溶液浇铸膜则形成了网状结构,且PS相为连续的网络,PI相则分散在网孔中。实验证明:溶剂的选择性不同导致了多接枝共聚物的相形态有显著差异,而且其相转变行为也受到溶剂选择性的影响。

The PI-g-PS film whose backbone is polyisoprene and polystyrene as branched chains was casted from a series of different selective solvents,including 1,4-dioxane,toluene and cyclohexane cyclohexane.Phase morphology of multi-graft copolymer cast from different solvent was studied by synchrotron-SAXS and TEM.It was found that the d-spacing decrease with the increasing of solvent selectivity for polystyrene.The phase morphology casted from Cyclohexane（the selective solvent of PI）and toluene（nonselective solvent）has PS cylinders dispersed in PI matrix,while the film casted from 1,4-dioxane（the selective solvent of PS）form mesh structure,meanwhile PS formed continuous net-work and PI dispersed in the PS matrix.Experiments confirmed that the solvent selectivity led to the different morphologies of graft copolymer significantly and the phase transition behavior was also influenced by solvent selectivity.