攪拌方法，乳化劑及反應溫度對苯乙烯乳化聚合反應之影響

Effect of Agitation, Emulsifier and Temperature on the Emulsion Polymerization of Styrene

呂銘坤(Meng-Kun Lu) ； 許俊顯(Jin-Sheng Sheu) ； 陳芳柏(Fong-Bo Chen) ； 王福泉(Fu-Chuang Wang)

《化學》 62年2期 (1973/06) Pp. 55-62

https://doi.org/10.6623/chem.1973010

摘要

本研究係以實驗方法配合理論而探討攪拌方法與速度，乳化劑種類與濃度，及反應溫度對苯乙烯乳化聚合速率之影響。由於攪拌速度提高可使乳化劑吸附於單量體粒上之量增加，而減少誘導反應期産生聚合體顆粒之微胞數目，因此，預備乳化時之攪拌速度愈大，聚合速率愈小。如以相同之高速攪拌先作預備乳化時，反應進行中不同之攪拌速度並不影響其聚合速率。實驗中曾使用陰離子乳化劑與非離子乳化劑，在各種乳化劑之臨界微胞濃度以上而低於其一定之極大值以下，提高乳化劑濃度可使聚合體顆粒數增加。或許由於陰離子乳化劑是膠態電解質之類的緣故，其聚合速率較使用非離子乳化劑時爲高。反應溫度提高，可使聚合速率增加，但黏度平均分子量減少。在不同之反應溫度與乳化劑濃度情況下，曾利用電子顯微鏡照相，以研究乳化聚合反應之聚合體顆粒大小與數目之變化情形。

並列摘要

This work is an experimental study of the effects of agitation intensity, type and concentration of the emulsifiers, and the reaction temperature on the rate of emulsion polymerization of styrene. Higher agitation intensity in preparing the emulsion decreases the polymerization rate. This is because the agitation tends to increase the amount of emulsifier adsorbed on monomer droplets and reduce the number of emulsifier micells which produce polymer particles during the induction period of the reaction. Once the emulsion is prepared in a specified condition, the agitation intensity during the reaction period has no effect on the polymerization rate. Both anionic and nonionic emulsifiers have been employed. The number of polymer particles increases with the concentration of the emulsifiers, and it has a certain maximum value for each kind of emulsifier. Anionic emulsifiers give higher polymerization rate. This is perhaps because they are colloidal electrolytes. The rate of polymerization increases and the viscosity-average molecular weight decreases with an increase in reaction temperature. The electron microscopic technique is used for the study of the number and size of. polymer particles of emulsion polymerization prepared using different reaction temperatures and emulsifier concentrations.