Comparison of Dielectric and Viscoelastic Relaxation Functions of cis-Polyisoprenes: Test of Tube Dilation Molecular Picture
Comparison of Dielectric and Viscoelastic Relaxation Functions of cis-Polyisoprenes: Test of Tube Dilation Molecular Picture
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顺式聚异戊二烯的介电和粘弹性弛豫功能的比较：管扩张分子图片测试
DOI：
10.1021/ma991121q
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发表时间：
2000
期刊：
影响因子：
5.5
通讯作者：
K. Osaki
中科院分区：
文献类型：
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作者：
Yumi Matsumiya;and Hiroshi Watanabe;K. Osaki
在广义管模型的背景下，表示纠缠约束的管不一定在空间中固定，而是随时间移动。这种管运动会导致约束释放 (CR) 以及管内链的动态管扩张 (DTD)。对于单分散系统，DTD 分子图像导致归一化松弛模量 μ(t) (=G(t)/GN) 与扩张管的存活分数的平方成正比。相反，具有非反转A型偶极子的链的归一化介电弛豫函数Φ(t)与该分数成比例。因此，如果管在链弛豫的时间尺度上膨胀，则粘弹性和介电弛豫函数满足关系 μ(t) = [Φ(t)]2。对于具有这些 A 型偶极子的线性顺式聚异戊二烯 (PI) 链，检查了这种关系的有效性。这种关系大致有效，因此，对于处于散装状态的 M/Me = 10−30 的 PI 链，管会膨胀，尽管……
Within the context of the generalized tube model, the tube representing the entanglement constraint is not necessarily fixed in space but moves with time. This tube motion results in constraint release (CR) as well as dynamic tube dilation (DTD) for the chain trapped in the tube. For monodisperse systems, the DTD molecular picture leads to the normalized relaxation modulus μ(t) (=G(t)/GN) being proportional to square of the surviving fraction of the dilated tube. In contrast, the normalized dielectric relaxation function Φ(t) of the chain having noninverted type-A dipoles is proportional to this fraction. Thus, the viscoelastic and dielectric relaxation functions satisfy a relationship μ(t) = [Φ(t)]2 if the tube dilates in time scales of the chain relaxation. The validity of this relationship was examined for linear cis-polyisoprene (PI) chains having those type-A dipoles. The relationship was approximately valid, and thus, the tube dilated for the PI chains with M/Me = 10−30 in their bulk state, although...