Unperturbed dimensions of atactic poly(dibenzyl itaconate)s  

作　　者：MA Hai-zhu YE Gao-xiang 

机构地区：[1]Department of Physics, Zhejiang University, Hangzhou 310027, China [2]School of Science and Technology, Zhejiang Education Institute, Hangzhou 310012, China

出　　处：《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》2007年第7期991-998,共8页浙江大学学报（英文版）A辑（应用物理与工程）

基　　金：Project supported by the National Basic Research Program (973) of China (No. 10574109);the Zhejiang Provincial Science and Technology Department (No. 2005C24008);the Natural Science Foundation of Zhejiang Province (No. Y604064), China

摘　　要：The unperturbed dimension and temperature character of poly(dibenzyl itaconate)s (PDBzI) are studied by a revised rotational isomeric state (RIS) method. The improved formulas of the mean-square radius of gyration, deduced by the pseudo-stereochemical equilibrium approach, may be used to investigate the configurational-conformational properties of atactic polymers with large side groups [poly(itaconates) for instance]. The calculated results showed that poly(itaconates) have larger dimension of the molecule than other vinyl polymers. Comparison of the dimension between considering and without considering side groups showed that the effect of large side groups on the unperturbed dimension for short-chain polymers is more obvious than that of long-chain polymers and, if the dimension of side groups increases, the effect also increases. The dimension differences of PDBzI between short-chain and long-chain polymers are investigated by the relation of characteristic ratios and temperature coefficients with temperature. Moreover, the dependence between the temperature coefficients and the tacticity of chains shows that the temperature characters of the isotactic, syndiotactic and atactic PDBzI chains have remarkable difference.The unperturbed dimension and temperature character of poly（dibenzyl itaconate）s （PDBzI） are studied by a revised rotational isomeric state （RIS） method. The improved formulas of the mean-square radius of gyration, deduced by the pseudo-stereochemical equilibrium approach, may be used to investigate the configurational-conformational properties of atactic polymers with large side groups [poly（itaconates） for instance]. The calculated results showed that poly（itaconates） have larger dimension of the molecule than other vinyl polymers. Comparison of the dimension between considering and without considering side groups showed that the effect of large side groups on the unperturbed dimension for short-chain polymers is more obvious than that of long-chain polymers and, if the dimension of side groups increases, the effect also increases. The dimension differences of PDBzI between short-chain and long-chain polymers are investigated by the relation of characteristic ratios and temperature coefficients with temperature. Moreover, the dependence between the temperature coefficients and the tacticity of chains shows that the temperature characters of the isotactic, syndiotactic and atactic PDBzI chains have remarkable difference.

关 键 词：Poly（dibenzyl itaconate）s Mean-square radius of gyration Temperature coefficient TACTICITY 

分 类 号：O469[理学—凝聚态物理] O631.2[理学—电子物理学]