摘要
以苯乙烯（ Ｓｔ） 和甲基丙烯酸甲酯（ Ｍ Ｍ Ａ） 为主单体，以丙烯酸（ Ａ Ａ） 为功能单体进行了无皂乳液批量共聚合．考察了功能单体浓度、引发剂过硫酸铵（ Ａ Ｐ Ｓ） 浓度及聚合温度对其动力学行为的影响．建立了转化率时间关系曲线的模型函数——— Ｇａｍ ｍａ 积分函数，用它拟合了转化率时间关系曲线，获得了聚合过程的重要特征参数，如平均成核速率（ Ｎ Ｖ） ，聚合最大速率（ Ｍ Ｖ） 和平稳期平均聚合速率（ Ａ Ｖ） 及成核结束和聚合进入完成期对应的转化率．同时对聚合速率与以上各聚合参数的关系数据进行了非线性拟合，得到了它们之间的关系式．研究发现拟合误差很小，成核结束时转化率在１５ ％ 以内，成核及聚合速率均随以上参数增大而增大，引发剂过硫酸铵在聚合过程中起决定作用．
The emulsifier free emulsion copolymerization of styrene ( St) and methylmethacrylate ( M M A) in the presence of functional monomer acrylic acid ( A A) was carriedout in batch process. Effects of concentration of functional monomer A A, initiatorconcentration [ A P S] and polymerization temperature T on the kinetics of thecopolymerizatuion were investigated . Model function of cumulative conversion vs .reactiontime ——— Integrated Gam ma Function was built up ,and was empolyed to fitthe samples ofcumulative conversion versus reaction time. The maximum polymerization rate ( M V) ,average polymerization rate ( A V) inthesteady stage ,average nucleation rate( N V) andthecorresponding cumulative conversionsat momentof nucleation stage ceasing and atthe steadystage completing were estimated by calculating extremums and inflexions of it○s fitted Gam ma Function . Whereafter, the polymerization rate versus each single polymerizationparameter was analyzed with non linear fitting and the related equation was obtained . Theresults show that the fitting error is very small and both the nucleation rate andpolymerization rateincrease with increasing [ A A] ,[ A P S] and polymerization temperature T. Among these reaction parameters,[ A P S] playsa predominantrolein the polymerization . The cumulative conversion is within 15 % when the nucleation stage ceases.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
1999年第5期534-539,共6页
Acta Polymerica Sinica
关键词
无皂乳液聚合
乳液聚合
三元
共聚合
动力学
Ternary emulsifier free emulsion copoymerization , Kinetics and model ofpolymerization , Non linearfitting , Functional monomer, Gam ma function
