Hard-coating materials for poly(methyl methacrylate) from glycidoxypropyltrimethoxysilane-modified silatrane via a sol–gel process

Hard-coating suspensions for improving the scratch resistance of poly(methyl methacrylate) (PMMA) surfaces have been developed by a sol–gel processing method of silatrane in the presence of 3-glycidoxypropyl-trimethoxysilane (GPTS) using 1 M HCl as a catalyst. Poly(methyl methacrylate) substrates were dipped into the coating solutions and dried at 60 °C for half an hour before being cured at 120 °C for 2 h. The addition of GPTS to silatrane suspensions enabled the formation of dense and transparent thin-film with smooth surface on the substrates. The scratch resistance of the coated surface was found to increase with increasing GPTS to silatrane ratio. Both the curing time and curing temperature were found to affect the scratch resistance and adhesion properties of the coating layer.