Sol-Gel Materials, 1. Synthesis and Hydrolytic Condensation of New Cross-Linking Alkoxysilane Methacrylates and Light-Curing Composites Based upon the Condensates

Abstract

New methacryloyxyalkylaminoalkylalkoxysilanes have been synthesised by Michael addition of the corresponding acryloyloxyalkyl methacrylates with (3-aminopropyl)triethoxysilane (APTES). Low-viscosity polycondensates have been formed by hydrolysis and condensation of these silanes in the presence of ammonium fluoride (NH 4 F). The reaciton of APTES with the addition product of succinic or glutaric anhydride with glycerol dimethacrylate results in the formation of new dimeth-acrylate-functionalised 3-amidopropyltrithoxysilanes. The hydrolic condensation of these silanes was carried out in the presence of 0.5 M HCI. The hydrolysis and condensation of the silanes have been studied by 29 Si NMR spectroscopy. Cross-linked inorganic-organic materials have been obtained by free-radical photopolymerisation of the polycondensates and their mixtures in the presence of camphorquinone and ethyl 4-(dimethylamino)benzoate with visible light (VL). The synthesised polycondensates enable the preparation of diluent-free composites. The mechanical properties of VL-cured polycondensates and composites have been investigated.