Synthesis And Properties Of Silicone Modified Pvp Hydrogel Soft Contact Lens Materials

N-vinylpymolidone-co-2-hydroxyethyl methacrylate (NW-co-HEMA) copolymer had been widely studied and used as soft contact lens and controlled-releasing materials in foreign countrys. But this hydrogel material's oxygen penetration capability was closely correlated to its equation water content. When the hydrogel had high equation water content, its oxygen penetration capability was improved, but its mechanism performance was droped. In order to improve PVP hydrogel material's mechanism and penetrability, Gamma-(methylacryloyl-oxy)propyl- trimethoxysilane(trademark) was choosed to modify polyvinyl- pyrrolidone (PVP) hydrogels. The synthesis and capability of organic silicon modified PVP hydrogel contact lens material was mainly studied in this article. NVP-HEMA-KH570 copolymer was prepared by noumenon polymerization method, N,N'-methylene bisacrylamide(NMBA) as crosslinker and azobis iso butyro nitrile (AD3N) as initiator.The factors which influenced hydrogel material's mechanical intensity were researched, such as temperature, monomer content etc. The introduction of organic silicon KH570 could improve the material's draw intensity notably, the increase of NW content droped the material's draw intensity. The results of the uni-factor experiments and perpendicular experiments show their best mechanic synthesizing craft as followed: NVP(10%Wt), KH570(20%Wt), HEMA(70%Wt), initiator (0.2%Wt), crosslinker (20%Wt), reacting 20 hours under 80 C.The factors which influenced organic silicon modified PVP hydrogel soft contact lens material's swelling capabilities were researched, which included temperature, monomer content, ion concentration etc. The experiments showed the equation swelling content EWC improved with the increase of NW, droped with the increase of KH570 and ion concentration, improved then droped with the raise of temperature, and hydrogels got the least EWC at 45 C.Experiment carried on todiscuss water dehydration mechanism of organic silicon modified PVP hydrogel soft contact lens materials, which showed dehydration processcould be divided into evaporating stage and diffusing stage. The factors which influenced material's dehydration capabilities were researched, which included temperature, monomer content, ion concentration etc. The experiments showed the introduction of organic silicon KH570 could drop the material's dehydration speed.Cavity- embrane method was adopted to study oxygen and ion penetration capabilities of organic modified hydrogel material, and the oxygen penetration mechanism and ion diffusing mechanism were discussed too. The factors which influenced hydrogel material's penetration capability were researched, which included temperature, monomer content, ion concentration, film thickness of hydrogel etc. We found the introduction of organic silicon KH570 could improve PVP hydrogel's oxygen and sodium ion penetration capabilities. The penetration capability of hydrogel material was increased to lead then droped with the increase of KH570 content, and improved with increase of NVP content. The highest oxygen penetration rate was 45cm3/ (cm2-s-mmHg), while the highest sodium ion penetration coefficient was 0. 63 XKT6 cmVs.The optics capability and stability of organic silicon KH570 modified PVP hydrogel contact lens material were perfect too.