Biaxial Deformation of a Polymer Network Measured via Deuteron Quadrupolar Interactions
Biaxial Deformation of a Polymer Network Measured via Deuteron Quadrupolar Interactions
复制标题
通过氘核四极相互作用测量聚合物网络的双轴变形
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
E. Samulski
中科院分区：
文献类型：
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作者：
P. T. C. and;E. Samulski
氘四极相互作用已被用来测量平面双轴拉伸下的聚（二甲基硅氧烷）弹性体的链有序。从两个不同的氘标记的探针分子在网络内扩散获得的NMR光谱分裂作为扩展比λ和变形主轴相对于磁场的取向的函数进行测量。基于幻影高斯链模型的理论预测与数据进行了比较，并发现良好的协议。轴向不对称的探针分子运动层次的各个级别的影响进行了讨论。对于快速扩散的探针分子，只有最高层次的影响所观察到的四极相互作用的对称性，并测量链段董事的真实分布。
Deuterium quadrupolar interactions have been used to measure chain ordering for poly(dimethylsiloxane) elastomers under planar biaxial extension. The NMR spectral splittings obtained from two different deuterium-labeled probe molecules diffusing within the network were measured as a function of extension ratio λ and the orientation of the principal axis of deformation with respect to the magnetic field. Theoretical predictions based on a phantom Gaussian chain model are compared with the data and good agreement is found. The implications of axial asymmetry at various levels of the probe molecule motional hierarchy are discussed. For rapidly diffusing probe molecules, only the highest level in the hierarchy influences the observed quadrupole interaction symmetry, and the true distribution of chain segment directors is measured.