Effect of Mesophase Separation on the Crystallization Behavior of Olefin Block Copolymers
Effect of Mesophase Separation on the Crystallization Behavior of Olefin Block Copolymers
复制标题
中间相分离对烯烃嵌段共聚物结晶行为的影响
DOI：
10.1021/ma102075c
复制
发表时间：
2010-12-28
期刊：
影响因子：
5.5
通讯作者：
Han, Charles C.
中科院分区：
文献类型：
--
作者：
Jin, Jing;Du, Jiang;Han, Charles C.
研究了中间相分离对不同辛烯含量的烯烃嵌段共聚物结晶行为的影响。在OBCs中，结晶总是与中间相分离同时发生，但相互竞争。由于OBCs的结晶温度低于中间相分离温度，中间相分离可以先开始；大部分可结晶硬块被限制在中间相分离的畴内，不能形成径向片层堆。此外，中间相分离产生立体位阻效应；晶片只能通过分散畴之间的间隙生长。因此，不能形成大而致密的晶体。随着样品中辛烯含量的增加，中间相分离越来越占优势，晶体形态从5 ~ 10℃急剧退化。
This paper investigates the effect of mesophase separation on the crystallization behavior of olefin block copolymers (OBCs) with different octene contents, which were synthesized by chain shuttling technology. Crystallization always occurs simultaneously but competitively with mesophase separation in OBCs. Because of the reason that the crystallization temperature is lower than the mesophase separation temperature for the OBCs, the mesophase separation can start first; large portions of the crystallizable hard blocks are confined in the mesophase-separated domains and could not contribute to the formation of radial lamellar stacks. In addition, the mesophase separation creates a stereo-hindrance effect; crystal lamellae could only grow through the interstitial space between the dispersed domains. As a result, large and compact crystals could not be formed. As the octene content increased in the sample, mesophase separation becomes more and more dominant, and the crystal morphology degrades sharply from s...