Synthesis And Characterization Of A Contact Lens Materials

Development and application of silicone hydrogel contact lens materials is the biggest breakthrough in the field in recent years.For current high oxygen permeability silicone hydrogel material research has developed three generations,the majority of listed products is foreign brands such as CIBA Vision,Bausch&Lomb,Johnson&Johnson,It has higher product prices.Most of the country is still in the research stage.In recent years,with manufacturers have been publicized in the short-cycle concept,it has been accepted by the vast majority of consumers,consumer focus are biased in favor of short-cycle products in the economic capacity allows.Disposable products is increasing in the proportion of overall sales,An increase the number of repeated consumption contains is virtually booming power market development by an increase the number of repeated.Currently,silicone hydrogel lenses on the market is still largely concentrated in monthly disposable,it is expensive.This topic is committed to developing a low-cost daily disposable or bi-weekly disposable silicone hydrogel contact lenses.Under the control of the experimental product costs possible to improve the oxygen permeability of the material.Both to meet the consumer mentality philosophy,while maintaining the consumer to contact lenses more comfortable to wear health requirements.The experiment has synthesized a new silicone hydrogel contact lenses by bulk polymerization.It using hydroxyethyl methacrylate(HEMA),N-vinyl pyrrolidone(NVP),and y-(methacryloxypropyl)trimethoxysilane(KH-570)three monomers and Azo-bis-isobutyronitrile(AIBN)as initiator.The experiments to determine the amount of initiator,the reaction temperature and the optimum reaction conditions of crosslinker.Study focused on various monomer ratio for oxygen permeability and water content of the impact,considering the silicone hydrogel contact lens transmittance,a variety of factors pH,stability and fatigue strength of the material,etc.,to determine the optimal synthesis scheme:When the reaction temperature is 90?,the reaction time was 2h,V(HEMA):V(NVP):V(KH-570)= 7.5:1.5:1,the contact lens oxygen permeability(Dk/t)synthesis reached 65.0 × 10-9(cm3O2 · cm)/(cm2 · s· mmHg),Water content 38%or more light transmittance of 95.5%.