Conformation transition and crystalline phase variation of long chain branched isotactic polypropylenes (LCB-iPP)
文献类型：期刊论文
| 作者 | Su, Zhiqiang; Wang, Hongying; Dong, Jinyong; Zhang, Xiuqin; Dong, Xia; Zhao, Ying; Yu, Jian; Han, Charles C.; Xu, Duanfu; Wang, Dujin |
| 刊名 | POLYMER
 |
| 出版日期 | 2007-01-26 |
| 卷号 | 48期号:3页码:870-876 |
| 关键词 | Long Chain Branched Isotactic Polypropylene Conformation Transition Crystallization Behavior |
| ISSN号 | 0032-3861 |
| DOI | 10.1016/j.polymer.2006.12.013 |
| 英文摘要 | The changes of conformation and crystalline structure of long chain branched isotactic polypropylene (LCB-iPP) under different crystallization temperatures and the effects of their special molecular architecture on the crystallization behavior were investigated by a combination of Fourier transform infrared spectroscopy (FT-IR), wide-angle X-ray diffraction (WAXD) and differential scanning calorimetry (DSC). In these polymers, long chain branching was introduced via in situ polymerization of polypropylene and an asymmetric diene monomer using the metallocene catalyst technology. Through the characterization of the specific IR band variation, it was proved that the conformational orders of helical sequences of LCB-iPP show great changes in different crystallization temperature ranges. In lower crystallization temperature range (100-130 degrees C), the intensities of all regular helical conformation bands of LCB-iPP increase with the increasing crystallization temperature and the regular helical conformation bands with more monomer units increase faster than that with less monomer units. In higher crystallization temperature range (130-150 degrees C), the intensities of all regular helical conformation bands of LCB-iPP decrease with the increasing crystallization temperature and the regular helical conformation bands with more monomer units decrease faster than that with less monomer units. The results of WAXD and DSC showed that LCB-iPP crystallizes from the melt as a mixture of alpha and gamma forms. The content of the gamma form increases with the increasing crystallization temperature, reaches a maximum value at 130 degrees C, and then decreases with a further increase of the temperature. At the same time, the crystallization of gamma form is favored by the presence of the LCB structure of iPP. Moreover, the transitional temperatures of different helical conformations and crystallization structures of LCB-iPP show obvious correlations. (c) 2006 Elsevier Ltd. All rights reserved. |
| 语种 | 英语 |
| WOS记录号 | WOS:000244125300023 |
| 出版者 | ELSEVIER SCI LTD |
| 源URL | [http://ir.iccas.ac.cn/handle/121111/62261]  |
| 专题 | 中国科学院化学研究所 |
| 通讯作者 | Wang, Dujin |
| 作者单位 | 1.Chinese Acad Sci, Inst Chem, Beijing Natl Lab Mol Sci, CAS Key Lab Engn Plast,Joint Lab Polymer Sci & Ma, Beijing 100080, Peoples R China 2.Tsing Hua Univ, Sch Mat Sci & Engn, Dept Chem Engn, Inst Polymer Sci & Engn, Beijing 100084, Peoples R China |
| 推荐引用方式 GB/T 7714 | Su, Zhiqiang,Wang, Hongying,Dong, Jinyong,et al. Conformation transition and crystalline phase variation of long chain branched isotactic polypropylenes (LCB-iPP)[J]. POLYMER,2007,48(3):870-876. |
| APA | Su, Zhiqiang.,Wang, Hongying.,Dong, Jinyong.,Zhang, Xiuqin.,Dong, Xia.,...&Wang, Dujin.(2007).Conformation transition and crystalline phase variation of long chain branched isotactic polypropylenes (LCB-iPP).POLYMER,48(3),870-876. |
| MLA | Su, Zhiqiang,et al."Conformation transition and crystalline phase variation of long chain branched isotactic polypropylenes (LCB-iPP)".POLYMER 48.3(2007):870-876. |
入库方式： OAI收割
来源：化学研究所
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