欢迎您！东篱公司
退出
-
申报数据库
-
立项数据库
-
成果数据库
-
项目获奖数据库
中文摘要：
聚乙烯基环己烷一聚乙烯-聚乙烯基环己烷（PVCH—PE-PVCH）是美国Dow化学公司开发的一种有望成为现今聚碳酸酯光盘等存储材料的替代材料．该嵌段共聚物是由聚苯乙烯-聚丁二烯-聚苯乙烯（PS-PB-PS）氢化得来的．其有序-无序转变温度（tODT）约为250℃，体系的相分离能力强．其中PVCH的玻璃化转变温度（tg）约为140℃，而由PB氢化得来的PE均聚物的熔点约为110℃．故当该嵌段共聚物从熔体冷却结晶时，体系首先发生微相分离，自组织形成纳米尺度的有序结构．随着温度继续降低，PVCH发生玻璃化转变，以冻结的玻璃态存在，使得由微相分离形成的纳米有序结构得以相对固定．同时PE分子链的两端也被PVCH固定．进一步降温到PE的结晶温度时，PE开始在由微相分离形成的纳米几何空间里受限结晶，结晶受限导致其熔点和结晶度都显著降低．然而关于其受限结晶影响要素的研究还不多见，仍有许多模糊的认识需要澄清．
英文摘要：
The melting and recrystallization behaviour of poly （ vinylcyclohexane ） -b-poly （ethylene） -b-poly （vinylcyclohexane） （ PVCH-PE-PVCH ） triblock copolymer in supercritical carbon dioxide （ CO2 ） was investigated by using of DSC. The effect of the rate of the depressurization of CO2 on the crystallization of the samples was also examined. It is found that there are three melting peaks on each DSC curve of the samples treated in supericritical CO2 at the temperature above tm of the untreated PVCH-PE-PVCH. They corresponded to the ＂hard＂ confined crystallization of PE blocks homogeneous nucleation, the ＂soft＂ confined crystallization of PE blocks homogeneous nucleation and the self-seeding nucleation free crystallization of PE blocks respectively. Furthermore, these three kinds of crystallization could be controlled by changing the competition between the crystallization of PE block and the vitrifaction of PVCH block in the samples, which depended on the rate of the depressurization of CO2.
同期刊论文项目
同项目期刊论文
Wetting-layer formation mechanisms of surface-directed phase separation under different quench depth
Dispersion and Noncovalent Modification of Multi-walled Carbon Nanotubes by Various Polystyrene-base
Effects of Micelle Structures Formed in Selective Solvents on Crystallization Behaviors of Poly (eth
Control of the confined and unconfined crystallization in glassy- crystalline poly(vinylcyclohexane)
期刊信息
位置：