Preparation And Research Of Gradient Materials Of Organosilicon Polymer-Poly (Methy1 Methacrylate)

In this paper, the emulsifier sodium polyether sulfovinate modified polysiloxane was synthesized by sulfuric acid esterification between chlorosulfonic acid and polyether modified polysiloxane, then alkali neutralization. It was a kind of nonionic and anionic composite emulsifier. Compared with emulsifier unesterified, it has higher cloud point, which could apply to conventional emulsion polymerization.With sodium polyether sulfovinate modified polysiloxane and sodium lauryl sulfate as composite emulsifier system, using methyl methacrylate(MMA) and self-made monomer γ-[tris(trimethylsiloxy)silyl]propyl methacrylate(TRIS) as raw materials, we prepared the homopolymer of TRIS, MMA, and the copolymers (P(MMA-co- TRIS)) by means of semi continuous dropwise method of monomer emulsion. Then, IR, TEM, DMA and water contact angle measurements were utilized to study these polymers and their films. The result indicated that we can get stable homopolymer and copolymer emulsion with uniform size distribution, when the ratio of sodium polyether sulfovinate modified polysiloxane to sodium lauryl sulfate was two, the quantity of the emulsifiers ranged from 6% to 8%(relative to monomer), the quantity of initiator ranged from 0.4% to 0.8%(relative to monomer), the stirring speed ranged from 200rpm to 250rpm, the polymerization temperature was 80 centigrade degree. As for the copolymer emulsion, the more the TRIS content in the monomers, the larger the water contact angle of their films became, namely, the surface energy of the copolymer films increased with the TRIS content in the monomers. In addition, the glass-transition temperature of the copolymers ranged from high temperature region to low temperature region with the increasing of TRIS content in the monomers.The study of blend manner of homopolymer and copolymer emulsion indicated that we can improve the miscibility between PMMA and PTRIS by adding P(MMA-co-TRIS) copolymer, and we can obtain organosilicon polymer-poly(methyl methacrylate) gradient films with poly(methyl methacrylate) at the top surface and organosilicon polymer at the bottom one. The analysis result of DMA, DSC, UV measurements showed that the glass-transition range of the gradient films was wider than the component ones, and the gradient films had good thermo-stability, hydrophobicperformance and absorption capacity to ultraviolet ray.