The effect of chain interpenetration on an ordering process in the early stage of polymer crystal nucleation
The effect of chain interpenetration on an ordering process in the early stage of polymer crystal nucleation
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DOI：
10.1016/j.polymer.2006.05.001
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发表时间：
2006-06
期刊：
影响因子：
4.6
通讯作者：
Zhuqing Zhang;Xiaozhen Yang
中科院分区：
文献类型：
--
作者：
Zhuqing Zhang;Xiaozhen Yang
在本研究中，链的互穿程度被认为是在高分子链系统的缠结的结构属性。使用链间径向分布函数（RDF）进行测量。我们将这种方法应用于一个模型系统，在该模型系统中，通过分子动力学（MD）在原子水平上模拟了聚合物晶体成核早期的有序化过程。初始链结构具有不同程度的互穿，并在400K下经历了有序化过程。结果表明，在纳秒尺度下，互穿程度对有序化过程有显著的阻碍作用，这与实验室时间尺度下的实验结果一致。链之间的这种行为表明，在原子水平上，蠕变聚合物链能够识别“管”上的相邻基团是否来自相同的链或其他链。这种认识表明，链的爬行时间将受到“管”的组成或相互渗透的程度的影响。结果表明，在有序化过程中，互穿程度变化不大，说明在模拟条件下，链段的运动主要受有序化过程的控制，而不是进一步调整缠结程度。
In the present study, the degree of chain interpenetration was considered as a structural attribute of the entanglements in polymer chain system. Inter-chain radial distribution function (RDF) was used to perform this measurement. We applied this method to a model system, in which an ordering process in the early stage of polymer crystal nucleation at the atomistic level was simulated by means of molecular dynamics (MD). Initial chain structures possessed different degrees of interpenetration and underwent the ordering process at 400K. Obtained results indicated that at the nanosecond scale the degree of interpenetration impedes the ordering process remarkably, which agrees with the experimental observation at laboratory time scale. Such behavior among chains indicates that at the atomistic level a creeping polymer chain is able to recognize if the neighbor group on the ‘tube’ is from the same chain or other chains. This recognition manifests that the reptation time of a chain would be influenced by the ‘tube’ composition or the degree of interpenetration. It also showed that the degree of interpenetration changes little during the ordering process, which means that the motion of the chain segments is mainly predominated by the ordering process rather than further adjusting the entanglement extent under the conditions simulated.