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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