丙烯酰胺与二甲基二烯丙基氯化铵共聚动力学

摘要

采用膨胀计法研究了以过硫酸铵-亚硫酸氢钠为引发剂,丙烯酰胺(AM)和二甲基二烯丙基氯化铵(DMDAAC)在水溶液中的共聚反应动力学,测定了相应的聚合表观活化能、聚合速率方程和单体竞聚率.结果表明,当AM与DMDAAC摩尔比分别为5:5、6∶4和7∶3时,表观活化能分别为Ea1=90.61 kJ/mol、Ea2=88.88 kJ/mol和Ea3 =85.15 kJ/mol;聚合反应温度为45℃下,聚合速率方程分别为Rp1=k(M)2.845C(Io)0.51·c(IR)0.61,Rp2 =kc(M)2.77c(Io)0.51c(IR)0.59和Rp3=kc(M)2.73c(Io)0.50c(IR)0.56;2种单体的竞聚率分别为rAM=6.11,rDMDAAC =0.14.上述实验结果可从动力学角度为不同阳离子度共聚物Poly( DMDAAC-co-AM) (PDA)聚合反应速率差别及产物特征黏度值差异进行解释.%The kinetics of polymerization of acrylamide ( AM) and dimethyldiallylammonium chloride (DMDAAC) initiated by ammonium persulfate-sodium bisulfate redox complex in aqueous solution was studied. The polymerization rate equation was obtained, and the apparent activation energy and reactivity ratio were measured. The results show that when the polymerization temperature is 45 °C , n( AM):n( DMDAAC) is 5:5, 6=4 and 7:3, the polymerization rate equations are ftpl = fa;( M)2(!4c(I0)0-51c(IR)0-61, R# = fcc(M)277 c(I0)051c(IR)059 and ^ = itc(M)273c(I0)050c(IR)056. The apparent activation energies are ￡al = 90. 61 kj/mol, E& = 88. 88 kj/mol and ￡.3 = 85. 15 kj/mol, respectively, while the reactivity ratios of AM and DMDAAC are rAM = 6. 11, rDMDAAC = 0. 14. The kinetics results could explain the difference of copolymerization rate and intrinsic viscosity of poly(DMDAAC-co-AM) (PDA) with different cationicities.