环型聚苯乙烯结构与性能的研究

本文通过多种分析测试手段，详细研究了环型聚苯乙烯（ＲＰＳ）分子链结构、聚集态结构、热性能及稀溶液性质，并与线型聚苯乙烯（ＬＰＳ）作了对照。结果表明：ＲＰＳ链结构确为环状结构，由于链结构不同于ＬＰＳ，因此链刚性及其随分子量的变化关系也不同于ＬＰＳ，这是导致其性质与ＬＰＳ存在很大差异的根本原因。ＲＰＳ链堆积较ＬＰＳ松散，由于线团密度ＲＰＳ大于ＬＰＳ，所以宏观上二者比容并无多大差异，但ＲＰＳ比容受分子量影响较ＬＰＳ大。ＲＰＳ的Ｔｇ随分子量变化关系受自由体积和构象熵即链刚性两种因素的影响。动态光散射及小角Ｘ光散射实验结果说明，ＲＰＳ的扩散行为、流体力学半径和无扰分子尺寸与ＬＰＳ相比有很大不同。

A Study of the Structure and Property of Ring shaped PS

A study of the structure of molecular chain and aggregation state, thermal performance and dilute solution property of ring shaped PS (RPS) was made by several analyses and determinations, and a comparison was also made with linear shaped PS (LPS). The results showed the chain structure of RPS was really a ring shaped structure and different from that of LPS, making its chain stiffness and the relation of the chain stiffness with molecular weight different from those of LPS, which was the basic reason for the great difference of the properties of RPS and LPS. The chain conglomeration of RPS was looser than that of LPS, and because the coil density of RPS was greater than that of LPS, there was no much difference between the specific capacity of RPS and LPS by macromgrapy. Owing to its molecular weight, the specific capacity of RPS was greater than that of LPS. The change of T g with molecular weight of RPS was effected by free volume and conformational entropy (chain stiffness). The results of dynamic light scattering and small angle X ray scattering tests showed there was great difference between the diffusion behavior,fluid mechanic radius and unperturbed molecular dimension of RPS and LPS.