Silicone / Acrylic Hybrid Copolymer Emulsion Preparation Process

In this paper, the effect of different polymerization technological process on the performance of acrylic ester emulsion grafted by organic silicone was compared, and the organic silicone—acrylic ester emulsion with excellent film performance was prepared by pre-emulsified semi-continuous emulsion polymerization. The effect of various polymerization technical conditions and factors on the film performance, polymerization stability and kinetics were studied, including monomer species and mixture ratio; the content of functional monomer; the choice and the dosage of emulsifier and mixture ratio of nonionic emulsifier and anionic emulsifier; initiator concentration; the type, dosage and addition order of organic silicone; pH value; polymerization temperature and agitation intensity.Hydrolytic condensation of organic silicone is easily happened in the organic silicone—acrylic ester emulsion polymerization, which hinder the radical polymerization between organic silicone and acrylic ester. In order to solve this problem, two methods has been adopted to control the hydrolytic condensation of organic silicone in our experiment. One is dropping organic silicone with hunger in the later reaction. Another is using NaHCO₃ to adjust pH between 5 to 7.Though FTIR , we has found that the hydrolytic condensation of organic silicone has been controlled effectively by using two methods. The mechanism of polymerization hasalso been studied------the radical polymerization between organic siliconeand acrylic ester happened first and then hydrolytic condensation of organic silicon happened , the character of water-fast,dirt-resistant,temperature-resistant and mechanics has been improved obviously.