Influence of long-chain branching on linear viscoelastic flow properties and dielectric relaxation of polycarbonates
文献类型：期刊论文
| 作者 | Liu, CY; Li, CX; Chen, P; He, JS; Fan, QR |
| 刊名 | POLYMER
 |
| 出版日期 | 2004-04-13 |
| 卷号 | 45期号:8页码:2803-2812 |
| 关键词 | Long-chaIn BranchIng In Polycarbonate Rheology Dielectric Relaxation |
| ISSN号 | 0032-3861 |
| DOI | 10.1016/j.polymer.2004.02.030 |
| 英文摘要 | The dynamic viscoelastic property, creep and creep recovery behavior, and dielectric relaxation of long-chain branched Bisphenol A polycarbonates were measured in parallel plate rheometer and dielectric analyzer. The linear polycarbonate (PC-L) as reference and three branched polycarbonates (PC-Bs) have similar molecular weights and molecular weight distributions, while the PC-Bs have different branching degrees, below 0.7 branch points/chain and above twice of M-c. The long-chain branched polycarbonates exhibit higher zero-shear viscosities, more significant shear shinning, higher flow activation energies, and much longer relaxation times. It was also found that long-chain branches increase the elasticity of melt characterized by the steady-state recoverable compliance and the storage modulus. The 'dissident' rheological behavior of long-chain branching exhibiting mainly in addition polymers such as polyolefin, is confirmed in condensation polymers. These behaviors resulted from additional molecular entanglements of long-chain branches can be understood qualitatively in terms of the tube model for topological constraints. The dielectric a-relaxation of linear polycarbonate and branched polycarbonates has been fitted with Vogel-Fulcher-Tammann-Hesse (VFTH) equation and the shape of relaxation time curves is also analyzed. The long-chain branched polycarbonates present longer relaxation times, but divergent a-relaxation temperatures, because the latter is dominated by the free volume. (C) 2004 Elsevier Ltd. All rights reserved. |
| 语种 | 英语 |
| WOS记录号 | WOS:000220533500035 |
| 出版者 | ELSEVIER SCI LTD |
| 源URL | [http://ir.iccas.ac.cn/handle/121111/55691]  |
| 专题 | 中国科学院化学研究所 |
| 通讯作者 | He, JS |
| 作者单位 | 1.Chinese Acad Sci, Inst Chem, Ctr Mol Sci, State Key Lab Engn Plast, Beijing 100080, Peoples R China 2.Chinese Acad Sci, Inst Chem, Ctr Mol Sci, State Key Lab Polymer Phys & Chem, Beijing 100080, Peoples R China |
| 推荐引用方式 GB/T 7714 | Liu, CY,Li, CX,Chen, P,et al. Influence of long-chain branching on linear viscoelastic flow properties and dielectric relaxation of polycarbonates[J]. POLYMER,2004,45(8):2803-2812. |
| APA | Liu, CY,Li, CX,Chen, P,He, JS,&Fan, QR.(2004).Influence of long-chain branching on linear viscoelastic flow properties and dielectric relaxation of polycarbonates.POLYMER,45(8),2803-2812. |
| MLA | Liu, CY,et al."Influence of long-chain branching on linear viscoelastic flow properties and dielectric relaxation of polycarbonates".POLYMER 45.8(2004):2803-2812. |
入库方式： OAI收割
来源：化学研究所
浏览0
下载0
收藏0
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。