中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
The polydispersity of ethylene sequence in metallocene ethylene/alpha-olefin copolymers III: crystallization and melting behavior of short ethylene sequence

文献类型:期刊论文

作者Zhang, FJ; Song, M; Lu, TJ; Liu, JP; He, TB
刊名POLYMER
出版日期2002-02-01
卷号43期号:4页码:1453-1460
ISSN号0032-3861
关键词Metallocene Ethylene/alpha-olefin Copolymer Modulated-temperature Differential Scanning Calorimetry Polydispersity
英文摘要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. (C) 2001 Elsevier Science Ltd. All rights reserved.
语种英语
出版者ELSEVIER SCI LTD
WOS记录号WOS:000172824400049
源URL[http://ir.iccas.ac.cn/handle/121111/78429]  
专题中国科学院化学研究所
通讯作者He, TB
作者单位1.Chinese Acad Sci, Changchun Inst Appl Chem, State Key Lab Polymer Phys & Chem, Changchun 130022, Jilin, Peoples R China
2.Loughborough Univ Technol, Inst Polymer Technol & Mat Engn, Loughborough LE11 3TU, Leics, England
3.Liaoning Univ, Coll Chem Sci & Engn, Liaoning 110036, Peoples R China
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.

入库方式: OAI收割

来源:化学研究所

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