Synthesis And Study On New Material Of Contact Lens

The industry of contact lens has been developed rapidly since the first material—PMMA came out. As was reported, the market of contact lens in China increased 10% in 2002 and 14% in 2004. Contact lens are not only hoped to rectify eyesight but also rectify astigmatism, prevent ultraviolet radiation, change the color of eye and so on. There are two main ways to research contact lens(technology and material) in this paper. On one hand, contact lens material was prepared from NVP and HEMA by UV method and the performance of the product was studied. One the other hand, we prepared poly (γ-glutamic acid)(γ-PGA) hydrogel from glycol diglycidyl ether andγ-PGA and analysed the product also.Poly(2-hydroxyethylmehtacrylate-N-vinylpyrrolidone)(PHEMA-NVP) was prepared by UV method(UV light :40W). Benzoin ethyl ether was used as UV sensitive initiator. The optimal conditions are as follow: the concentration of initiator is 1.6%, irradiation distance is 2.6cm, the reaction is complete. And the surface of the product is slick.The color contact lens was prepared from NVP, HEMA and solvent blue 36. Mechanism of the reaction was studied. According to the test, the pigment did not take part in the reaction; it was just absorbed on the material. The transparency of the product which was put in the 0.9%NaCl solution for 24h was 97%, the same value as before. It proved that the product was steady in the tear.The performance of the contact lens was analysed in this paper. The optimal conditions are as follow: the monomers(MHEMA:MNVP=3:2), the UV sensitive initiator(benzoin ethyl ether1.6%),and the pigment(solvent blue 36)( 0.00246%). the water content was 66.51%, transparency was 97%,tensile modulus was 916.23pa, and the pH range from 7.09 to 7.29, it was near to tear. IR and UV verified perfectibility of the reaction. SEM analysis suggested that the sample had higher water content and tensile modulus.At last, A new polymer was prepared fromγ-poly(glutamic acid) (γ-PGA) and glycol diglycidyl ether. The conditions of the reaction, such as PGA concentration, crosslinking agent, pH, temperature, time were studied. The optimal conditions are as...