种子法制备高固含量聚醋酸乙烯乳液

Preparation of High-Solid Content Polyvinyl Acetate Emulsion by Seeding Polymerization

以半成品VAE乳液作种子,采用氧化-还原引发体系和半连续乳液聚合工艺合成了固含量不低于60%(未加入DBP),黏度约3000mPa.s的聚醋酸乙烯乳液;考察了种子乳液、保护胶体、表面活性剂对乳液黏度、滤渣、贮存稳定性的影响;测试了产品应用性能。

In order to obtain a high-solid content PVAc（Polyvinyl Acetate） emulsion, VAE（Vinyl Acetate-Ethylene） seed emulsion was added before emulsion polymerization. In the presence of a surfactant system comprising PVA（Polyvinyl Alcohol） and a nonionic surfactant, the PVAc emulsion which had a solids level of greater than about 60 % and a coating viscosity of 3000 mPa·s at 25℃ was prepared by using the method of increasing particles diameter. The effects of the amount of seed emulsion on polymerization rate, viscosity, particles diameter of PVAc emulsion, the amount of protective colloid and surfactant on viscosity, grit, stability of PVAc emulsion were investigated. The result of experimentation shows that the seed emulsion additon ranges from 5.1%- 6.9%; the optimum amount of PVA is 4.2%, and nonionic surfactant is 0.7% ; the filmforming rate and setting speed of high-solid content PVAc emulsion are superior to conventional PVAc emulsion.