正十二硫醇对氯丁橡胶相对分子质量及其分布和支化程度的影响

Effect of concentration and charging methods of n dodecyl mercaptan on MW, MWD and branching of polychloroprene

采用正十二硫醇作为相对分子质量调节剂于１０℃下进行了氯丁二烯乳液聚合，研究了硫醇浓度、加入方式、补加量以及单体转化率对氯丁橡胶相对分子质量及其分布、支化程度的影响。结果表明，采用硫醇分批加入方式，在较高单体转化率下仍能得到相对分子质量分布均匀、支化程度较低的聚合物。

The emulsion polymerization of chloroprene was conducted at 10℃ with n dodecyl mercaptan as chain transfer agent, potassium salt of disproportionated rosin acid as emulsifier and potassium persulfate/sodium sulfite/sodium anthraquinone 2 sulfonate as redox initiator. The effects of mercaptan concentration and its charging methods, and monomer conversion on molecular weight and its distribution, and branching content of polychloroprene were investigated. It was shown that high molecular weight polychloroprene with narrow molecular weight distribution and low branching extent could be obtained when mercaptan was charged in two increments at appropriate monomer conversion.