Study On Influence Factors Of Synthesis Process And Product Properties Of Silicone-acrylic Emulsion

In this paper, many influence factors of polymerization process and product properties of organic silicone modified acrylic ester emulsion are studied, such as complex emulsifier systems, initiator, organic silicone monomer and acrylic ester monomers, reaction temperature and stirring intensity and so on. The whole study can be divided into two parts.In the first part, the emulsifier,catalyst and other factors,which can influence the seeded emulsion polymerization of organic silicone modified acrylic ester emulsion are discussed. The purpose,on the one hand,is to choose reasonable emulsifier, catalyst and other raw materials;on the other hand,is to choose reasonable reaction temperature, stirring intensity and other process conditions. The experimental results shows, if the ratio between MS-1 and OP-10 rangs from 1:1 to 3:l,and the total dosage of them is about 20% of Octamethylcyclotetrasiloxane (D4 ) in quality, we can obtain a kind of stable seeded emulsion of organic silicone modified acrylic ester emulsion. At the same time, if the ratio between MS-1 and Tetramethylammonium Chloride(TMAC )is l:1.7,the total dosage is about 50% of D4 in quality; the ratio between MS-1 and Cetyltrimethylammonium Chlorine (CTAC )is 7:1, the total dosage is about 25% of D4 in quality,we can also obtain stable seeded emulsions. But if the complex emulsifier system is made of TMAC and OP-10, MS-1 and Peregal O or CTAC and Span-80, we can not synthesize any kind of satisfactory seeded emulsions. In addition, the experiment also finds that NaOH can not be used as catalyst in the synthesizing process of organic silicone modified acrylic ester emulsion,in contrast, Dodecylbenezene Sulfonic Acid (SDBA) is a good choose.In the second part, the synthesis of organic silicone modified acrylic ester emulsion is discussed. The main process is: the seeded emulsion was put into the reactor, then, the mixture of Methylmethacrylate (MMA) and Butyl Acrylate (BA) is dripped successively and gradully into the reactor,while Ammonium Persulfate(APS) and Acrylic Acid (AA) are added regularly into the reactor.The whole process must be carried out under a proper reaction temperature andstirring intensity. In this part,a large number of single-factor experiments combined with orthogonal experiments are carried out to study the influence factors of the polymerization process and the properties of emulsion products or their films. Transmission Electron Microscope (TEM) and other properties testing results show that the complex emulsifier system is the crucial influence factor of the polymerization process and the properties of products. It may influence the coagulum content and reaction rate of the polymerization process, the performance, particle diameter,viscosity, electrolyte stability and storage stability of the emulsion products and the contact angle of the film.The initiator mainly influences the coagulum content and reaction rate.The acrylic monomers mainly influence the solid content, Minimum Film Formation Temperature(MFT) of the emulsion and the Glass Transition Temperature (Tg) of the film.The organic silicone monomer mainly influences the water absorption of the film.The reaction temperature mainly influences the reaction rate and conversion.The stirring intensity mainly influences the coagulum content of the polymerization process.