Entanglement dynamics in ultra-high molecular weight polyethylene as revealed by dielectric spectroscopy
Entanglement dynamics in ultra-high molecular weight polyethylene as revealed by dielectric spectroscopy
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DOI：
10.1016/j.polymer.2018.07.021
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发表时间：
2018-08-15
期刊：
影响因子：
4.6
通讯作者：
Ronca, Sara
中科院分区：
文献类型：
--
作者：
Drakopoulos, Stavros X.;Psarras, Georgios C.;Ronca, Sara
利用宽带介电谱技术，可以在较宽的温度和频率范围内研究超高分子量聚乙烯的分子动力学行为。氧化铝的催化灰作为介电探针，允许识别五种不同的过程：由于结晶相的运动的α（c）-过程，归因于接近结晶层的无定形链部分的两个γ-过程，以及我们归因于解缠结和缠结的无定形相的两个β-过程。纠缠的形成已经遵循等温运行，从而提出了一个模型，预测所花费的能量作为时间和温度的函数形成纠缠。我们的工作进一步加深了对超高分子量聚合物的纠缠动力学的理解，所提出的模型可以用来描述其他类似的过程，如交联. (C)2018作者爱思唯尔有限公司出版
With the help of Broadband Dielectric Spectroscopy, it has been possible to study the molecular dynamics of disentangled Ultra High Molecular Weight Polyethylene in a wide temperature and frequency range. Catalytic ashes of aluminum oxide act as dielectric probes, allowing the identification of five different processes: an alpha(c)-process due to movements in the crystalline phase, two gamma-processes attributed to amorphous chain portions close to the crystalline lamellae, and two beta-processes that we have attributed to the disentangled and entangled amorphous phases. The entanglement formation has been followed by isothermal runs and a model that predicts the energy spent to form entanglements as a function of time and temperature is thereby proposed. This model allowed us to calculate the associated activation energy of the entanglement process.Our work advances further the understanding of entanglement dynamics of ultra-high molecular weight polymers, and the proposed model could prove useful to describe other similar processes such as cross-linking. (C) 2018 The Authors. Published by Elsevier Ltd.