The polydispersity of ethylene sequence in metallocene ethylene/alpha-olefin copolymers III: crystallization and melting behavior of short ethylene sequence

	The polydispersity of ethylene sequence in metallocene ethylene/alpha-olefin copolymers III: crystallization and melting behavior of short ethylene sequence
	Zhang FJ ; Song M ; Lu TJ ; Liu JP ; He TB
刊名	polymer
	2002
卷号	43 期号:4 页码:1453-1460
关键词	HOMOGENEOUS COPOLYMERS BUTENE COPOLYMERS POLYETHYLENE MORPHOLOGY 1-OCTENE
ISSN号	0032-3861
通讯作者	he tb
中文摘要	crystallization and melting behavior of short ethylene sequence of metallocene ethylene/alpha -olefin copolymer with high comonomer content have been studied by standard dsc and modulated-temperature differential scanning calorimetry (m-tdsc) technique. in addition to high temperature endotherm around 120 degreesc, a low temperature endotherm is observed at lower temperatures (40-80 degreesc), depending on time and temperature of isothermal crystallization. the peak position of the low temperature endotherm t-m(low) varies linearly with the logarithm of crystallization time and the slope, d, decreases with increasing crystallization temperature t-c. the t-m(low) also depends on the thermal history before the crystallization at t-c, and an extrapolation of t-m(low) (30.6 degreesc) to a few seconds has been obtained after two step isothermal crystallization before the crystallization at 30 degreesc. the t-m(low) is nearly equal to t-c, and it indicates that the initial crystallization at low temperature is nearly reversible. direct evidence of conformational. entropy change of secondary crystallization has been obtained by using m-tdsc technique. both the m-tdsc result and the activation energy analysis of temperature dependence suggest that crystal perfection process and conformational entropy decreasing in residual amorphous co-exist during secondary crystallization.
收录类别	SCI收录期刊论文
语种	英语
WOS记录号	WOS:000172824400049
公开日期	2010-11-03
内容类型	期刊论文
源URL	[http://202.98.16.49/handle/322003/18853]
专题	长春应用化学研究所_长春应用化学研究所知识产出_期刊论文
推荐引用方式 GB/T 7714	Zhang FJ,Song M,Lu TJ,et al. The polydispersity of ethylene sequence in metallocene ethylene/alpha-olefin copolymers III: crystallization and melting behavior of short ethylene sequence[J]. polymer,2002,43(4):1453-1460.
APA	Zhang FJ,Song M,Lu TJ,Liu JP,&He TB.(2002).The polydispersity of ethylene sequence in metallocene ethylene/alpha-olefin copolymers III: crystallization and melting behavior of short ethylene sequence.polymer,43(4),1453-1460.
MLA	Zhang FJ,et al."The polydispersity of ethylene sequence in metallocene ethylene/alpha-olefin copolymers III: crystallization and melting behavior of short ethylene sequence".polymer 43.4(2002):1453-1460.