End-Linked Poly(dimethylsiloxane) Elastomers: 2H-Nuclear Magnetic Resonance Investigations of Compression-Induced Segment Anisotropy
End-Linked Poly(dimethylsiloxane) Elastomers: 2H-Nuclear Magnetic Resonance Investigations of Compression-Induced Segment Anisotropy
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末端连接的聚（二甲基硅氧烷）弹性体：压缩引起的段各向异性的 2H 核磁共振研究
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发表时间：
1997
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通讯作者：
T. Duncan
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作者：
K. McLoughlin;J. K. Waldbieser;C. Cohen;T. Duncan
应用2 H-NMR光谱测量聚二甲基硅氧烷（PDMS）弹性体中三种环境中聚合物链段的应变诱导取向各向异性：弹性链、侧链和溶解在网络中的PDMS（d）链。制备的弹性体具有系统变化的结构和选择性氘标记。网络功能推断宏观测量使用统计和热力学模型。在单轴压缩PDMS网络的三种环境中，链段序参数S与λ2 − λ-1成正比，其中λ是压缩比：弹性链、悬挂链和溶解探针链。此外，在0.089 - 0.29 MPa范围内，所有三种环境都显示出比值S/（λ2-λ-1）对弹性模量的相同依赖性。这些结果同意最近的理论预测Brereton和里斯（大分子1996年，29日，2644），从而支持的前提下，排除体积（熵）相互作用…
2H-NMR spectroscopy is applied to measure strain-induced orientational anisotropy of polymer segments in three environments in poly(dimethylsiloxane) (PDMS) elastomers: elastic chains, pendant chains, and PDMS(d) chains dissolved in the network. The elastomers were prepared with systematically-varied structures and selective deuterium labeling. Network features were inferred from macroscopic measurements using statistical and thermodynamic models. The segment order parameter, S, was found to be proportional to λ2 − λ-1, where λ is the compression ratio, for the three environments in uniaxially-compressed PDMS networks: elastic chains, pendant chains, and dissolved probe chains. Furthermore, all three environments show the same dependence of the ratio S/(λ2 − λ-1) on the elastic modulus, in the range 0.089−0.29 MPa. These results agree with the recent theoretical predictions of Brereton and Ries (Macromolecules 1996, 29, 2644) and thus support the premise that the excluded volume (entropic) interactions ...