月桂酸甲酯磺酸钠乳化剂的制备及其在丙烯酸酯乳液聚合中的应用

以月桂酸为原料、甲醇为酯化剂、氯磺酸为磺化剂，通过酯化、磺化、中和等反应制备了月桂酸甲酯磺酸钠（C12-MES），计算和测定了亲水亲油平衡值（HLB）、临界胶束浓度（CMC）和三相点（K点），并将其作为乳化剂应用于丙烯酸酯的乳液聚合，考察了乳化剂用量对单体转化率、乳液稳定性、乳胶粒粒径的影响。结果表明，当月桂酸甲酯与氯磺酸物质的量比为1:1.2，熟化时间60 min，且用质量分数为20%的甲醇再酯化，所得C12-MES产品色泽较浅，活性物含量能达到80%以上，其HLB值、CMC、K点分别为14.7、13.20 mmol/L（28 ℃）和0 ℃以下；以制得的C12-MES为乳化剂合成的丙烯酸酯共聚物乳液稳定，乳胶粒的粒径在100～200 nm之间，粒度分布小于0.015。

Synthesis of sodium methyl 2-sulfolaurate and its application in acrylate emulsion polymerization

Sodium methyl 2-sulfolaurate(C12-MES) was synthesized by esterification,sulfonation and neutralization steps using lauric acid as raw material,methanol as esterifying agent,and chlorosulfonic acid as sulfonating agent.Target products with light colour having more than 80% C12-MES were obtained with a molar ratio of methyl ester to chlorosulfonic acid of 1∶1.2,an aging time of 60 min,and 20% of methanol in the reesterification.Values of the hydrophile-lyophile balance(HLB),critical micelle concentration(CMC) and Krafft point of C12-MES were found to be 14.7,13.20 mmol/L(28 ℃),and below 0 ℃,respectively.In addition,C12-MES was employed as an emulsifier in acrylate emulsion polymerization.The stabilities of the resulting acrylate emulsions were good,the latex particle diameter ranged from 100 nm to 200 nm,and the polydispersities were less than 0.015.