On the Mechanism of Emulsion Polymerization of Styrene.
On the Mechanism of Emulsion Polymerization of Styrene.
复制标题
苯乙烯乳液聚合机理的研究。
DOI：
10.1021/j150543a024
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发表时间：
1956
期刊：
影响因子：
--
通讯作者：
B. Hoff
中科院分区：
文献类型：
--
作者：
B. Hoff
对苯乙烯乳液聚合的某些动力学方面进行了研究，以检验史密斯-埃沃特理论在每毫升水中含有1014个颗粒以上的胶乳中的有效性。用各种脂肪酸钾皂和过氧化氢异丙苯进行聚合。转换时间曲线主要由两条基本为直线的直线组成。在大约55%的转化率时，有一个向较低聚合速率的转变。聚合过程中测量的乳胶粒的溶胀度表明，单体液滴的消失与反应速度的变化相一致。根据速率数据和电子显微镜分析，得出在N=5×10~(14)~5×10~(15)/毫升范围内，每颗粒聚合速率Rp与颗粒浓度N之间的关系式为：Rp=Cn~-u。常数c取决于肥皂的浓度和性质。分子量数据也被解释为乳化剂在胶束消失后的聚合过程中起作用。这些不能用Smith-Ewart理论解释的结果与其他作者在类似系统中得到的数据进行了比较。
Some kinetic aspects of the emulsion polymerization of styrene were investigated to test the validity of the Smith-Ewart theory for latices containing more than 1014 particles per ml. water. Polymerizations were carried out with a variety of potassium fatty acids soaps and cumene hydroperoxide. The conversion-time curves consisted mainly oftwo essentially straight lines. At about 55% conversion there was a transition to a lower rate of polymerization. Swelling ratios of the latex particles, measured during polymerization, demonstrated that the disappearance of the monomer droplets coincided with the change in reaction rate. From rate data and electron micrograph analyses it was deduced that therate of polymerization per particle, Rp, and the particle concentration, N, in the range N= 5 X 1014 to 5 X 1015/ml., are related by Rp= cN~-u. The constant c depends on the concentration and the nature of the soap. Molecular weight data were also interpreted to indicate that the emulsifier plays a role in the polymerization process after the disappearance of micelles. These resultswhich cannot be explained by the Smith-Ewart theory were compared with data obtained in similar systems by other authors.