常规乳液聚合下提高(甲基)丙烯酸高碳醇酯转化率的途径

以丙烯酸十八酯、甲基丙烯酸甲酯为共聚单体,反应型乳化剂MIXSTAR 6550和非反应型非离子乳化剂NOVELUTION 390复配作为复合乳化剂,过硫酸铵为引发剂,研究了乳化剂用量、3种质子[H ⁺]及[H ⁺]浓度对聚合稳定性、丙烯酸十八酯共聚活性及总单体转化率的影响。结果表明:反应型乳化剂MIXSTAR 6550具有将强憎水的丙烯酸高碳醇酯摆渡到乳胶粒或增溶胶束中的能力,同时强的质子[H ⁺]降低了丙烯酸高碳醇酯的活化能,使丙烯酸高碳醇酯在常规乳液聚合条件下可与其他丙烯酸酯共聚。即使丙烯酸高碳醇酯引入量为45%,总单体转化率也可达97%以上,实现了(甲基)丙烯酸高碳醇酯在常规乳液聚合下可与其他单体进行理想共聚的目的。

Approach to Increase Conversion of Higher Alkyl (meth) acrylates through Conventional Emulsion Polymerization

In this paper, the emulsion copolymerization behavior has been investigated by using the octadecyl acrylate and methyl methacrylate as copolymerizable monomers, reactive emulsifier MIXSTAR 6550 and non-reactive nonionic emulsifier NOVELUTION 390 as complex emulsifier and ammonium persulfate as initiator at the presence of proton acid. The effects of the ratio and dosage of complex emulsifier, the kinds of proton acid, the hydrogen ion concentration ([H ⁺]) on the polymerizing stability, total monomer conversion and the polymerizing active of higher alkyl acrylate were investigated. The results showed that the higher alkyl acrylate can be carried to the solubilized micelles or latex particles by above reactive emulsifier, the copolymerizing active of higher alkyl acrylate can be enhanced greatly by adding proton acid, therefore, the copolymerization ability of higher alkyl acrylate with other monomer can easily be achieved through conventional emulsion polymerization. By optimizing the dosages of emulsifier and proton [H ⁺], the total monomer conversion can exceed 97%, even if the dosage of higher alkyl acrylate is 45wt%. The main purpose to achieve the normal copolymerization of higher alkyl (meth)acrylate with other monomers through traditional emulsion polymerization is realized in this study.