First-Order and Third-Order Nonlinearities from Medium-Amplitude Oscillatory Shearing of Hydrogen-Bonded Polymers and Other Viscoelastic Materials
First-Order and Third-Order Nonlinearities from Medium-Amplitude Oscillatory Shearing of Hydrogen-Bonded Polymers and Other Viscoelastic Materials
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DOI：
10.1021/acs.macromol.9b01650
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发表时间：
2019-11
期刊：
影响因子：
5.5
通讯作者：
S. Bierwirth;Gabriel Honorio;C. Gainaru;R. Böhmer
中科院分区：
文献类型：
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作者：
S. Bierwirth;Gabriel Honorio;C. Gainaru;R. Böhmer
采用中幅振荡剪切实验研究了端羟基聚二甲基硅氧烷的超分子弛豫模式。对于这些缔合熔体，这使我们能够识别除共价链结构外还存在的氢键中介结构的非线性流变学特征。确定了超分子模式和链状模式的一阶和三阶非线性参数，并与一系列流变模型的预测结果进行了比较。在非线性响应中可以识别出两种超分子模式的指纹。通过收集包括聚合物熔体、聚合物溶液和其他粘弹性流体在内的约35种材料的三阶非线性参数3Q0，证明了3Q0的最大值与出现该最大值的频率处的剪切模量值有关。讨论了这一实验发现的意义。
Medium-amplitude oscillatory shear experiments are employed to study the supramolecular relaxation modes in hydroxyl-terminated polydimethylsiloxane. For these associating melts, this allowed us to identify the nonlinear rheological signature of hydrogen-bond-mediated structures occurring in addition to those of the covalent chains. First-order and third-order nonlinearity parameters are determined for the supramolecular and chainlike modes to compare them with the predictions of an array of rheological models. Fingerprints of the two supramolecular modes can be recognized in the nonlinear response. By collecting third-order nonlinearity parameters 3Q0 for about 35 materials including polymer melts, polymer solutions, and other viscoelastic fluids, it is demonstrated that the maximum value of 3Q0 correlates with the magnitude of the shear modulus at the frequency at which this maximum occurs. The implications of this experimental finding are discussed.