Synthesis And Characterization Of Silicon-acrylate Core/shell Emulsion With High Silicon Content At Lower Temperature

Composite materials of polyacrylate and polysiloxane have an important application on many fields, but the compatibility of polyacrylate and polysiloxane is poor, and the conventional polymeric technology is hard to make the both combining completely. In this paper, the compound means of polyacrylate and polysiloxane was described in details. Meanwhile, the technology of the seed-emulsion polymerization was introduced, and the polymerization mechanism was analyzed. Moreover, with discussing the status and development of the core/shell silicon-acrylate emulsion, it could be concluded that the core/shell silicon-acrylate emulsion products had a broad application prospects.Anion ring-open polymerization was carried out with ocatmethyl cylcotetra-siloxane (D4) and tetra-methyl tetravinylcylcotetra- siloxane (Vi-D4) as the organic-silicon raw materials, allyl-polyoxyethylene ether (M-l) and octyl phenol ethoxylate-10 (OP-10) as the composite emulsifiers, dodecyl benzene sulfonic acid(DBSA) as the catalyst. Ring-open emulsion with high conversion was sythesized using the way of pre-emulsification batch addition which can increase the reactive time of ring- organicsilicon in the system.With the methyl methacrylate(MMA), butylacrylate (BA) and 2-hydroxypropyl acrylate (HPA) as the main monomers, the allyl-polyoxyethylene ether (M-1&M-2 ) as the composite emulsifiers, and the potassium-persulphate (KPS), sodium formaldehyde sulfoxylate (SFS) and 2,2'-Azobis (2-(2-imidazolin-2-yl) propane) dihydrochloride (VA-044) as the composite initiators, the stable silicon-acrylate core/shell emulsion of high silicon content (15%) was prepared by the seed-emulsion polymerization technology at low-temperature.The influence of the kind and dosage of emulsifiers, dosage of initiators, monomers content, dosage of organic silicon, the reaction temperature, the ratios of MM A and BA, dosage of HPA and Vi-D4 on conversion and grafting rate of monomer, water absorption ratio of film, particle morphology and size distribution were studied comprehensively. By orthogonal test method to determine the optimum conditions: dosage of emulsifier was 0.66g (100g system), dosage of the initiator was 2000 mg·Kg-1. mononer content was 30%, dosage of silicone was 15%, reaction temperature was50°C.The microcosmic characteristics of silicone-acrylate copolymer products were characterized by infrared spectroscopy, transmission electron microscopy (TEM) and laser particle size distribution. The product is proven and Silicone acrylate copolymer, which has core/shell structure. Meanwhile, The stablility of emulsion and application performance of latex film were tested by the Zeta potential, the thermal gravimetric analysis(TG), the differential scanning calorimetry(DSC) and the tensile properties testing, and the influences of adding organic-silicon on heat-resistance and mechanical properties of the film were studied.