丙烯酸酯类二元共聚物的玻璃化温度与组成的关系

THE RELATIONSHIP BETWEEN GLASS TRANSITION TEMPERATURE AND COMPOSITION OF RANDOM COPOLYMERS OF ACRYLATES

考虑连接单元对单体单元玻璃化温度的影响对 Fox方程进行了修正 ,用 Tgi1j表示不同连接情况下单体单元 1的 Tg。经验证 ,这个改进方程能比较准确地解释丙烯酸酯类二元无规共聚物的 Tg与组成的关系曲线的各种情况 ,同时计算结果表明两侧连接单元的侧链的长度、结构等因素对单体单元的 Tg 有很大的影响。丙烯酸酯类连接单元的侧链越短越紧凑 ,则丙烯酸酯类单体单元的玻璃化温度越高 ,反之亦然。同时对

Contributions of connected units to T g of concerned unit were considered and a modified Gordon Taylor expression was proposed to predict the T gs of copolymers lacking copolymerization kinetics data. T g ilj presents T g of concerned unit 1, such as methacrylate or methyl methacrylate with different connecting units. The results show that modified equation fits the experimental data exactly in different situations. It also shows that the change of T g of concerned unit is affected by the length and structure of the side group of the connecting units. The glass transition temperature of the concerned unit will increase when connected to units with short and compact side chains, and vice versa. The effect of tacticity on T g of PMMA has also been interpreted herein.