聚苯乙烯-聚氧乙烯-聚苯乙烯三嵌段共聚物的结晶行为研究

采用偏光显微镜和DSC技术研究了聚苯乙烯-聚氧乙烯-聚苯乙烯（PS-b-PEO-b-PS)三嵌段共聚物的结晶行为，实验结果表明，随着共聚物中聚氧乙烯含量的降低，形成清晰球晶的能力减弱，结晶度（Xc）、结晶熔融温度（Tm）、结晶温度（Tc）降低；先微相分离再结晶和微相分离与结晶同时进行两种热历史，前者会损失体系的Xc、Tm；当共聚物中聚氧乙烯的数均分子量为2000，质量分子数为18%和34%时，发现了等速降温双结晶体。

STUDY ON THE CRYSTALLIZATION BEHAVIOR OF POLYSTYRENE-b-POLY (ETHYRENE OXIDE)-b-POLYSTYRENE TRIBLOCK COPOLYMERS

The crystallization behavior of polystyrene b poly(ethyrene oxide) b polystyrene triblock(PS b PEO b PS) copolymers was investigated by optical microscopy and DSC technologies. The result shows that the PEO phase has a decreasing propensity for spherical crystallization and less cleaner spherical structures as the PEO content of the copolymers decreases. The X c, T m and T c decreases with decreasing PEO content. There exists a depression of X c and T m, if the micro phase separation is firstly formed before crystallization occurred, in comparison with that the micro phase separation and crystallization take place at a same time.