Pulse Propagation in End-Linked Poly(dimethylsiloxane) Networks

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• 作者：Moitreyee Sinha ; Burak Erman ; James E. Mark ; Thomas H. Ridgway ; and Howard E. Jackson
• 刊名：Macromolecules
• 出版年：2003
• 出版时间：August 12, 2003
• 年：2003
• 卷：36
• 期：16
• 页码：6127 - 6134
• 全文大小：120K
• 年卷期：v.36,no.16(August 12, 2003)
• ISSN：1520-5835

文摘

The speed of a propagating pulse in polymer networks is strongly influenced by theirmicroscopic structure. The measurement of pulse velocity can be used to determine network parameters,including the molecular weight of the network between chemical cross-links (M_c) and physical entanglements (M_e). We report an experimental method for determining these network parameters frommeasurements of transverse velocity in stretched samples of well-defined polymer networks. We measuredthe transverse propagation speed in end-linked poly(dimethylsiloxane) networks under uniaxial tensionas a function of the extension ratio, the degree of cross-linking, and the amount of swelling. To determineM_c and M_e from these measurements, we used the theory of elastic wave propagation and molecularmodels for the networks to relate network parameters to the wave velocity in deformed networks. Wecompare and contrast the values of network parameters obtained using this method with independentmeasurements of network characteristics from other measurement techniques.