用NMR弛豫研究溶液中聚苯乙烯的缠结特性  

THE ENTANGLEMENT BEHAVIOUR OF POLYSTYRENE SOLUTIONS OBSERVED BY NMR RELAXATION

作　　者：毛诗珍[1] 袁汉珍[1] 冯汉桥[1] 杜有如[1] 

机构地区：[1]中国科学院武汉物理研究所波谱与原子分子物理国家重点实验室

出　　处：《波谱学杂志》1996年第2期121-128,共8页Chinese Journal of Magnetic Resonance

摘　　要：详细研究了在θ溶剂环已烷和二氧六环中聚苯乙烯（ＰＳ）链的弛豫特性随分子量、浓度和温度的变化规律，发现在ＰＳ的溶液中同时存在拓扑缠结和凝聚缠结．前者的形成强烈的依赖于分子量、浓度和温度，而后者主要同浓度和温度有关．侧基苯环的层叠作用（即凝聚缠结）对ＰＳ的溶解过程及主链的运动有很大影响，从而对ＰＳ的溶液性质乃至固体性质起着决定性作用．另外还发现在不同分子量范围内，分子量对ＰＳ的弛豫特性的影响明显不同．这被解释为同溶液中ＰＳ链的缠结的形成，单位体积内缠结点数的增加等因素有关．The relaxation of polystyrene (PS) chains with different molecular weights and concentrations and at different temperatures have been studied in detail. Cyclohexane and 1,4-dioxane were used as the theta solvent and as good solvent respectively. It was found that the topological and cohesional entanglements exist simultaniously in polystyrene solutions. The former depends strongly on molecular weight, concentration and temperature, and the latter depends mainly on concentration and temperature.The interlocking structure of the side chain-aromatic rings (i. e. cohesional entanglement) has a great effect on the dissolution process and main chain motion of polystyrene, thus it determines the solution property and even the property of PS bulk. In addtion, chain molecular weights in different ranges in values have quite dif ferent effects on the relaxation of PS. This behaviour is related to the formation of PS chain entanglements in solutions, and the number of entanglement points in a unit vol ume.

关 键 词：驰豫时间 凝聚缠结 聚苯乙烯 NMR 

分 类 号：O632.13[理学—高分子化学]