用^(13)C NMR弛豫研究星形聚苯乙烯在溶液中的分子运动(Ⅱ)  

Studies on Molecular Motion of Star-shaped Polystyrenes in Solution by Carbon-13 NMR(Ⅱ)

作　　者：汪健[1] 华士英[1] 裘祖文 沈家(马总)[1] Wang Jian;Hua Shiying;Qiu Zuwen;Shen Jiacong(Jilin University,Changchun)

机构地区：[1]吉林大学化学系、理论化学研究所

出　　处：《高等学校化学学报》1988年第5期488-492,共5页Chemical Journal of Chinese Universities

基　　金：中国科学院科学基金。

摘　　要：对不同支化度和不同支链链长的20%(W/V)星形聚苯乙烯溶液测定了^(13)C NMR弛豫参数,用1g-x^(2)分布、Cole-Cole分布和构象跳跃模型对主链的分子运动进行了分析讨论,并对芳环侧基的内旋转运动也进行了分析,求出了活化能和跳跃速率。结果表明,轻度化学交联对相关时间分布有一定影响,对链段运动的势垒没有明显影响。支链链长对^(13)C NMR弛豫的影响和对线形聚合物的影响是类似的。The carbon-13 relaxation parameters were measured for star-shaped polystyrenes with different branch degree and different molecular weight of parent chain in a 20% (W/V) solution. The backbone segmental motion is interpreted in terms of the lg-X^(2), Cole-Cole and a conformational jump model. The internal rotation motion of aromatic ring is analysed and the activation energies and jump rates are obtained. The results show that light chemical crosslinks has, to some extent, an influence on the distribution of correlation time, but no distinct effect on the potential for segmental motion. The dependence of carbon-13 relaxation on the molecular weight is similar to that of linear polymers.

关 键 词：弛豫参数 活化能 跳跃速率 

分 类 号：TQ3[化学工程]