高固体分无凝胶丙烯酸酯乳液合成工艺探讨

为制备高固体分无凝胶丙烯酸酯乳液，探讨了聚合方法，单体和引发剂的加料方式，乳化剂用量和种类，以及保护胶体种类对丙烯酸酯乳液性能的影响。结果表明：全部预乳化效果最佳，4h内无凝胶产生；半连续滴加较一次性或分批加入更有利于乳液体系稳定；采用阴离子与非离子乳化剂复配及加入保护胶体有利于提高聚合体系的固含量。筛选出最佳的制备工艺条件：采用全部预乳化、半连续种子乳液聚合；以十二烷基硫酸钠（SDS）与烷基酚聚氧乙烯醚（OP-10）为复合乳化剂（质量比为1：1），其用量为3％；保护胶体量为0．8％；引发剂量为0.3％；反应温度为78℃；反应时间为4h；搅拌速率为400r／min。此条件下可合成固含量达60．03％的带蓝光乳白色丙烯酸酯乳液。

Discussion on Synthetic Technique of High Solid Acrylate Emulsion without Gel

In order to prepare high solid acrylate emulsion without gel,the factors which affect the properties of acrylate emulsion were investigated,such as polymerization ways,feeding method of monomer and initiator,the amount and type of emulsifier and protective colloid.The experimental results showed that the effect of complete pre-emulsification was the best without gel within 4 hours,and that semicontinuous distribution droplets was more beneficial to the stability of emulsion system than disposable or stage addition,and that solids content of polymerization system can be improved by use of combination with anionic and nonionic emulsifier,and adding protective colloid respectively.The optimum preparation technology was as follows:using complete pre-emulsification and semicontinuous seed emulsion polymerization technology,taking SDS and OP-10(the ratio of SDS and OP-10 was 1:1)as compound emulsifiers with 3% amount in total mass,the weight percentage content of protective colloid was 0.8%,initiator was 0.3%,reaction temperature and time were 78℃ and 4 h respectively,and stirring speed was 400 r/min.On these conditions,ivory-white and blue light acrylate emulsion having a solid content of 60.03% could be synthesized.