支链长度及支化程度对聚苯乙烯流变行为的影响  

Influence of Branch Length and Branching Level on Rheological Behaviors of Branching Polystyrene

作　　者：徐晓梅[1] 郑晓婷[1] 刘晶如[1] 俞强[1] 

机构地区：[1]常州大学材料科学与工程学院江苏省太阳能电池材料与技术重点实验室,江苏常州213164

出　　处：《高分子材料科学与工程》2015年第4期78-82,共5页Polymer Materials Science & Engineering

基　　金：江苏省太阳能电池材料与技术重点实验室资助项目

摘　　要：将窄相对分子质量分布三臂星形聚苯乙烯与线型聚苯乙烯共混组成支化聚苯乙烯体系,通过共混比例调节支化程度,研究了支链长度及支化程度对支化聚苯乙烯流变行为的影响。研究表明,支化程度对支化PS流变行为的影响与支链长度有关。对于长支链体系(支链的珚Mw,branch大于PS临界链缠结相对分子质量(Me)的2倍),由于支链对链缠结具有促进作用,随支化程度增加,分子间作用力增大以及链缠结程度加重的共同作用,导致支化PS的零剪切黏度(η0)增大。对于短支链体系(支链的珚Mw,branch小于Me的2倍),由于短支链对于链缠结具有抑制作用,随支化程度增加,支化PS的η0呈先增加后降低的变化趋势。长支链PS体系的非牛顿指数随支化程度增加而下降,呈现更加偏离牛顿流体的流动行为,其粘流活化能则随支化程度增加略有增大。Branching polystyrene systems were built up by mixing three arms star polystyrene with linear polystyrene,and the branching level was adjusted by the content of three arms star polystyrene in the mixture. The influence of branch length and branching level on rheological behaviors of branching PS was studied through rotational rheometer.The experimental results show that the effect of branching level on the rheological behavior of branching PS is significantly dependent on the branch length. In long-chain branching system,where 珚Mwof branch is much larger than 2Me,zero shear viscosity of branching PS increases gradually,and the non-Newtonian exponent of branching PS keeps decreasing with increase of the branching level,due to the promoted chain entanglement by long-chain branching. In addition,the flow activation energy increases slightly with increase of the branching level. In the short-chain branching system,where the 珚Mwof branch is less than 2Me,zero shear viscosity of branching PS demonstrates a tendency of increasing at beginning,and then drops down later with increase of the branching level.

关 键 词：支化聚苯乙烯 流变行为 支化程度 支链长度 

分 类 号：O632.13[理学—高分子化学]