摘要
通过采用差示扫描量热仪(DSC)主要研究了结晶-非晶嵌段共聚物聚乙烯基环己烷-b-聚乙烯-聚乙烯基环己烷(PVCH-b-PE-b-PVCH)溶液结晶样品的熔融与非等温再结晶过程.探讨了溶液结晶样品中微相分离结构的形成对嵌段共聚物受限结晶的影响,并发现样品在熔融后的非等温结晶过程中出现了多重结晶峰.通过对嵌段共聚物有序、无序相形态下非等温结晶行为的研究,揭示了嵌段共聚物相形态与非等温多重结晶峰的关系,澄清了非等温多重结晶峰的形成原因.
The melting and non-isothermal meh-recrystallization behaviour of poly（vinylcyclohexane）-b-poly- （ethylene） -b-poly （vinylcyclohexane） （ PVCH-b-PE-b-PVC H ） solution crystallized sample, which was obtained after isothermal solution crystallization,were investigated by means of DSC. It was found that different with the PVCH-b-PE-b-PVCH melt crystallized sample, the solution crystallized sample possessed a higher melting temperature in the heating process and multiple crystalline peaks in the non-isothermal meh-recrystallization process. In the solution crystallization step of the solution crystallized sample, due to the dissolution of PVCH blocks in p-xylene the extent of the PE confined crystallization is reduced, forming more perfect PE crystals, and thus the melting temperature is higher than that of the melt crystallized sample. On the same time, the crystallization of PE blocks in solution also causes respective aggregation of PE and PVCH blocks,accordingly an initial microphase-separated structure is formed. The segment mobility of PE blocks is relatively improved in the initial microphase-separated structure, resulting in the partially confined crystalline peak —— crystalline peak Ⅱ and the completely confined crystalline peak at low temperature —— crystalline peak Ⅲ. From the comparison of the slow cooling experiment and the quenching experiment,it was found that crystalline peak Ⅰ at high temperature related to the microphase-separated ordered structure of the block copolymer. The formation of the ordered structure induces the further aggregation of PE blocks,improving the PE crystallization, and thus PE blocks could crystallize at the high temperature. The confined crystallization behavior of the block copolymer is influenced by the microphase-separated structures of the block copolymer, resulting in nonisothermal multiple crystalline peaks of the PVCH-b-PE-b-PVCH solution crystallized sample. The corresponding relation between the phase structures and the muhiple crystallin
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2011年第3期313-319,共7页
Acta Polymerica Sinica
基金
国家自然科学基金(基金号20874056)
博士点基金(基金号200800030047)资助项目
关键词
结晶-非晶嵌段共聚物
非等温多重结晶
受限结晶
相形态
Crystalline-noncrystalline block copolymer, Non-isothermal multiple crystallization, Confinedcrystallization, Phase structures
