摘要
本文研究了聚甲基丙烯酸甲酯(PMAA)的立构规整性与T_8的关系,结果表明立构单元分布和含量均对T_8有显著影响。应用前文导出的理论关系,进一步处理了T_8和构象参数实验数据,用这种简单方法计算得的无扰尺寸温度系数和实验值一致。由此推论,不同立构PMMA链的T_8之差反映了它们局部择优链构象的不同。
The glass transition temperature (Tg) and unperturbed demensions of PMMAs with Bernoulli distribution of stereoregular diads were measured. It was found that T, of PMMA depends not only on their tacticity but also on the distfibution type of the diads. Therefore, the linearized equation representing the dependence of Tg on the content of iso-, syndic- and heterotriads can only be used for the PMMA with the same type of stereodiads distribution.The theoretical relationship proposed in our previous papei; was applied to analyse the data of Tg and unperturbed dimension for PMMAs having various tacticities. The temperature coefficients, dlno2/dT, calculated by this method show a good agreement with the experimental ones-
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
1990年第6期647-654,共8页
Acta Polymerica Sinica
基金
中国科学院重大课题基金
国家自然科学基金
关键词
PMAA
立构规整
TG
Poly (methyl methacrylate), Stereoregularity, Glass transition temperature,Conformation, Unperturbed dimension
