Strain Hardening in Model Polymer Brushes under Shear
Strain Hardening in Model Polymer Brushes under Shear
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DOI：
10.1021/la0000365
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发表时间：
2001-02
期刊：
影响因子：
3.9
通讯作者：
and Ramanan Krishnamoorti;E. Giannelis
中科院分区：
文献类型：
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作者：
and Ramanan Krishnamoorti;E. Giannelis
聚合物熔体刷大振幅振荡剪切的非线性动态响应进行了研究，使用端栓聚合物层状硅酸盐纳米复合材料的熔体状态流变学。这些模型熔体刷在中等应变幅度下表现出可逆的应变硬化，其特征在于存在转变的临界应变幅度，该临界应变幅度仅是层间距离的函数（即，硅酸盐部分）。这些结果与溶剂填充聚合物刷观察到的结果有质的不同。一个现象学的解释的基础上拉伸已经扭曲的链响应所施加的剪切和预测的熔体刷的空间填充要求提供解释这些独特的结果。
The nonlinear dynamic response of polymer melt brushes to large amplitude oscillatory shear is studied using melt state rheology of end-tethered polymer layered−silicate nanocomposites. These model melt brushes exhibit reversible strain hardening at moderate strain amplitudes, characterized by the presence of a critical strain amplitude for the transition that is only a function of the interlayer distance (i.e., silicate fraction). These results differ qualitatively from those observed for solvent-filled polymer brushes. A phenomenological explanation based on stretching of already distorted chains in response to the applied shear and predicated on the space filing requirements of a melt brush is provided to explain these unique results.