Of Nvp Terpolymer Hydrogel Contact Lens Materials

In this paper, the strong hydrophilic hydrogels are synthesized by copolymerization of NVP and HEMA with MMA or EMA. Some properties such as swelling of the hydrogels are studied , and hydrogel contact lenses materials with high properties are obtained.Through experilation, BPO is selected as the initiator. The basic copolymerization routine is decided properties as follow: mix the initiator BPO and the monomers, pass N2 to remove O:, and then react under optimun temperature.Influences of some factors such as use level of initiator, temperature and reaction time on the reaction are investigated. The optimun technical conditions obtained are: the content of BPO 0.1% of total of monomers, under 80癈 and reacting about 24 hours. It is found conversions of each monomer reaches 90% by analysing the leftover monomer in the product.studying on the product properties proves that the products show excellent chemical stability,thermal stability, transmittance, swelling property and intensity, and is according with the strong hydrophilic hydrogel contact lenses materials. Comparing NVP-HEMA-MMA with NVP-HEMA-EMA the latter is better.Through TG analysis, it is approximately account for that the content of freewater is about 40%. Studying on the swelling kinetic indicates that the swelling kinetic curves of the products both depart the standard curve of FickanThe couses of departing are explained.