Inorganic-organic hybrid coatings on polycarbonate. Spectroscopic studies on the simultaneous polymerizations of methacrylate and silica networks

Hybrid methacrylate-silica coatings derived from 3-(methacryloxypropyl)-trimethoxy silane were deposited on polycarbonate via hydrolysis-condensation reactions followed by UV curing (lambda = 253.7 nm). The formation of -Si-O-Si- (inorganic backbone) and polymethacrylate (organic) networks leading to the generation of hybrid structure was monitored by UV and Fourier transform infrared (FTIR) spectroscopies. UV and FTIR spectra showed complete polymerization of methacrylate groups during UV curing of the coatings. The silica network was initially formed through the hydrolysis-condensation reactions of alkoxy groups in the sol as evident from the appearance of FTIR peaks due to -Si-O-Si- vibrations. Further silanol (Si-OH) condensation reactions leading to the generation of more silica network were occurred simultaneously with methacrylate polymerization during UV photo curing of the coating. (C) 2002 Elsevier Science B.V. All rights reserved.