MA-EA和MA-n-BA二元共聚物的玻璃化温度  

Glass Transition Temperature of Methyl Acrylate-Ethyl Acrylate and Methyl Acrylate-N-Butyl Acrylate Copolymers

作　　者：刘国栋[1] 张利英[2] 王艳丽[1] 郭丹[1] 程翠然[1] 

机构地区：[1]河北工业大学高分子科学与工程研究所,天津300130 [2]保定职业技术学院教务处,河北保定071051

出　　处：《高分子材料科学与工程》2010年第12期88-91,共4页Polymer Materials Science & Engineering

基　　金：国家自然科学基金资助项目(20804013);河北省自然科学基金资助项目(B2007000019)

摘　　要：采用前期提出的共聚物Tg-组成关系方程研究了MA-EA、MA-n-BA二元共聚物的Tg,新方程中的周期共聚物Tg通过最小二乘法由无规共聚物Tg数据求取,相关周期共聚物的Tg为:Tg[ME]=274.6K、Tg[MB]=246.3K、Tg[MME]=286.3K、Tg[MMB]=262.8K、Tg[EEM]=262.3K、Tg[BBM]=236.7K,由此计算得到的理论值与实验值偏差极小,说明新方程能够更好地解释丙烯酸甲酯二元共聚物Tg与其组成及序列结构之间的关系。进一步预测了不同取代基时有序取代密度对聚丙烯酸甲酯Tg的影响规律,发现与对聚甲基丙烯酸甲酯Tg的影响规律不同,取代基的影响在高取代密度时才能显现。Bulk copolymerization of methyl acrylate （MA） with ethyl acrylate （EA） and n-butyl acrylate （n-BA） was carried out at 60 ℃. The relation of Tgs of MA-EA,MA-n-BA copolymers with their compositions and sequence distributions was investigated with an equation proposed previously in view of bond rotation flexibility which contains mole fractions of triads and Tgs of corresponding periodic copolymers. Tgs of corresponding periodic copolymers were obtained by using least square method from Tgs of the random copolymers to be Tg[ME]=274.6K,Tg[MB]=246.3K,Tg[MME]=286.3K,Tg[MMB]=262.8K,Tg[EEM]=262.3K and Tg[BBM]=236.7K. Excellent fitting results were obtained which show that the equation is very suitable to describe Tg-composition relationship of methyl methacrylate binary copolymers. The influence of substituent density on Tg of poly（methyl acrylate） （PMA） was also tentatively predicted. It is found that the Tg decreasing effect only reveals at higher substituent density.

关 键 词：二元共聚物 玻璃化温度 组成 取代基 

分 类 号：O631.22[理学—高分子化学]