氢化丁苯共聚物结构的核磁共振波谱表征——Ⅰ.^(13)C谱带的归属

NMR SPECTRUM CHARACTERIZATION OF HYDROGENATED STYRENE - BUTADIENE COPOLYMERS——Ⅰ. Peak Assignments of ^(13)C NMR Srectra

本文分别用JEOL FX-90Q和Bruker AM-300波谱仪测定了氢化聚丁二烯和氢化丁苯共聚物的~1H,^(13)-NMR谱,得到了分辨率较高的谱图和新的结构信息。借助DEPT技术确定了各谱带的CH或CH_2类型。利用Grant-Paul和Lindeman-Adams介绍的化学位移经验计算公式,考虑苯基对α、β和γ碳原子的影响,计算了各种三单元序列中有关碳原子的化学位移。对脂肪碳部分的28组谱带重新进行了归属。化学位移计算值与实测值基本相符,并得到了不同组成的模型聚合物^(13)C-NMR谱的各谱带强度变化规律的验证。

~1H -and ^(13)C - NMR spectra of hydrogenated polybutadiene and hydrogenated styrene - butadiene copolymers were examined in this paper on the JEOL FX- 90Q and Bruker AM-300 NMR spectrometers. Well resolved spectra and new structural information have been obtained. The kind of CH or CH_2 of each peak is determined by the DEPT technique. Chemical shifts of relevant carbon atoms in the triads were calculated using Grant-Paul and Lindeman -Adams empirical methods. The effect of phenyl group on α, β and γ carbon atoms has been considered. New assignments of 28 groups of peaks in aliphatic carbon atom region are given and confirmed by the correlation between the peak intensity and the composition of the model copolymers. The calculated chemical shift values are essentially consistent with experimental results.