对称聚硅氧烷链温度系数的理论研究  

Theoretical Study on Temperature Coefficient of Symmetrically Substituted Polysiloxanes

作　　者：马海珠[1] 依斯坎德尔.吾斯曼 

机构地区：[1]浙江教育学院物理系,浙江杭州310012 [2]新疆教育学院物理系,新疆乌鲁木齐830043

出　　处：《厦门大学学报（自然科学版）》2003年第6期768-771,共4页Journal of Xiamen University：Natural Science

基　　金：浙江省教育厅资助项目(20031251)

摘　　要：利用Flory的构象统计理论和改进的大侧基 旋转异构态模型方法,推导了对称双取代基链均方回转半径特征比〈S2〉/2xl2和温度系数d(ln〈S2〉)/dT公式,可以研究聚硅氧烷链的柔性及温度特性.根据聚二甲基硅氧烷链(PDMS)特征比与链长x关系和均方回转半径与温度T关系的公式,计算得到PDMS长链特征比和温度系数分别为1.086和0.76×10-3deg-1,与实验值分别为1.07和0.51×10-3～0.78×10-3deg-1范围符合.结构式为 [Si(C2H5)2O]x 和 [Si(C2H7)2O]x 的聚硅氧烷链具有比PDMS更大的特征比,因此它们的柔顺性相对变弱.By using the conformational statistical theory of Flory and the improved large side groupsrotational isomeric state method, the characteristic ratio of meansquare radius of gyration <S2>/2xl2 and its temperature coefficient d(ln<S2>)/dT of the symmetrically substituted polymer chain are deduced, by which the flexibility and temperature feature of polysiloxanes may be investigated. According to the formula of the characteristic ratio vs. the chain length x and the meansquare radius of gyration vs. temperature T for poly(dimethylsiloxane) (PDMS) , the ratio and its temperature coefficient of the large PDMS obtained by calculation are 1.086 and 0.76×10-3deg-1 respectively, which are in agreement with the experimental data 1.07 and the range 0.51×10-3～0.78×10-3deg-1.The other polysiloxanes, such as the structural terminology x and x, have larger ratio values than PDMS, and so the flexibility of them weaken relatively.

关 键 词：构象统计 旋转异构态 聚二甲基硅氧烷 温度系数 含硅聚合物 橡胶 聚硅氧烷链 

分 类 号：O634.41[理学—高分子化学] TQ333[理学—化学]