Internal motion in organosilicon polymers. II. Dimethylpolysilazanes crosslinked through silicon
Internal motion in organosilicon polymers. II. Dimethylpolysilazanes crosslinked through silicon
复制标题
有机硅聚合物的内部运动。
DOI：
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发表时间：
1970
期刊：
影响因子：
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通讯作者：
E. G. Rochow
中科院分区：
文献类型：
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作者：
F. Model;E. G. Rochow
用宽谱线核磁共振研究了有机硅聚合物的内部运动，并将其推广到一对通过三官能硅交联的二甲基聚硅氮烷。这些数据表明，在77°K时，所有硅氮烷都有相当大的内部运动。证据是存在的C3旋转的甲基，以及旋转或扭转振荡的Si（CH 3）2基团的聚合物主链。在加热时，可以看到NMR谱线变窄，这与额外运动的开始有关，包括链平移和链挠曲或弯曲。通过硅交联增加了链平移的屏障，同时降低了链挠曲或弯曲的屏障。
An investigation of the internal motion in organosilicon polymers by wideline nuclear magnetic resonance has been extended to a pair of dimethylpolysilazanes crosslinked through trifunctional silicon. The data suggest that there is considerable internal motion in all silazanes at 77°K. Evidence is presented for the presence of C3 rotation of the methyl groups, as well as rotation or torsional oscillation of the Si(CH3)2 groups about the polymer backbone. Upon warming the NMR line is seen to narrow, and this is associated with the onset of additional motion, including chain translation and chain flexing or bending. Crosslinking through silicon increases the barrier to chain translation while decreasing the barrier to chain flexing or bending.