丙烯酰胺辐射反相乳液聚合动力学研究

KINETICS OF RADIATION-INDUCED INVERSE EMULSION POLYMERIZATION OF ACRYLAMIDE SOLUTION

本文用膨胀计法研究了^(60)Coγ辐射引发丙烯酰胺反相乳液聚合动力学,用粘度法测定聚合物分子量,得到如下动力学表达式:R_p∝I^(0.6)[Am]^(1.0)[SPAN 80]^(0.3),M_p∝I^(-0.1)[Am]^(0.2)[SPAN 80]^(-0.2);由阿伦尼乌斯公式求出聚合速度的表观活化能E_?=20.9kJ/mol。聚合反应的转化率-时间曲线的形状受乳化时搅拌速度的影响。光学显微镜观测表明单体乳液和聚合物乳胶粒子大小无明显差别。基于以上结果,提出了单体液滴成核的机理。

The kinetics of ^(60)Co-Gamma rays initiated inverse emulsion polymeri-zation of acrylamide solution in kerosene with SPAN 80 as emulsifier has been stu-died dilatometrically. The following expressions have been determined for the conditionsinvestigated: R_p∝I^(0.8)[Am]^(1.0) [SPAN 80]^(0.3), M_v∝I^(-0.1)[Am]^(0.2) [SPAN 80]^(-0.2). Theoverall activation energy for the rate of polymerization is 20.9 kJ/mol. The shapes of the conversion-time curves are effected by the stirring rate of emul-sification. The diameters of most of the particles of monomer emulsions and polymerlatexes are estimated to be about 2 micrometers by optical microscope. Based on the foregoing results, a monomer-droplet-nuclcation mechanism is proposedfor the systems studied.