丙烯腈溶液共聚过程体系黏度变化的动态测定与理论分析  

Viscosity behavior of solution copolymerization of acrylonitrile and itaconic acid:on-line determination and theoretical analysis

作　　者：缪金根[1] 王世栋[1] 程振民[1] 周美华[2] 潘鼎[2] 

机构地区：[1]华东理工大学,化学工程联合国家重点实验室,上海200237 [2]东华大学高性能纤维及制品教育部重点实验室,上海201620

出　　处：《化工学报》2013年第2期742-748,共7页CIESC Journal

基　　金：上海市科委资助项目(07DJ14002,09DZ1100203)~~

摘　　要：通过BrookField DV-ⅢUltra可编程旋转流变仪实时测定了以偶氮二异丁腈为引发剂,二甲基亚砜为溶剂,丙烯腈-衣康酸二元溶液共聚合体系的零剪切黏度变化。同时设计相同条件的封管实验测定转化率,并利用Arrhenius-Frenkel-Eyring方程导出了适合描述丙烯腈溶液共聚合体系的零剪切黏度随固含量、温度及黏均分子量变化的经验关联式。结果表明,各工艺条件对体系黏度都有显著影响,原料配比细微的差别将导致最终原液黏度相差数百帕秒以上,调控黏度时需综合考虑。值得注意的是,所有实验条件下反应2～3h后,体系黏度激增1000倍以上,即从约2mPa.s的初始黏度迅速增加至2～3Pa.s;而当总单体含量达到28%时体系产生凝胶效应,反应一定时间后黏度急剧增长。另外发现,当体系达到某一临界固含量时,溶液中大分子发生链缠结,固含量微小的增量就会导致体系黏度剧增。A programmable torque rheometer was used for on-line determination of zero shear viscosity of solution copolymerization of acrylonitrile and itaconic acid in dimethylsulfoxide. The Arrhenius- Frenkel- Eyring equation was extended to identify the dependence of zero shear viscosity on polymer content, temperature and viscosity-average molecular weight of polyacrylonitrile. It was observed that under all of these process conditions, small differences in feed composition would give rise to a large variation on zero shear viscosity and ultimate viscosity to more than 100 Pa ~ s, so the control strategy for viscosity should be considered critically. The changes of reaction temperature seemed to be more effective than other methods. The viscosity increased quickly from about 2 mPa · s to 2--3 Pa · s in the first three hours under all experiment conditions which would greatly depress heat exchange and mixing efficiency. It was also found that viscosity increased dramatically as a result of gel effect when total overall monomer mass fraction was beyond 28% in feed. In addition, a small increase of polymer content could give rise to a great increase in viscosity when polymer content reached some critical values, which indicated that macromolecules were entangled severely in copolymerization solution.

关 键 词：黏度 聚丙烯腈 分子量 溶液聚合 碳纤维 

分 类 号：TQ342.31[化学工程—化纤工业]