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

New methacryloyloxyalkylaminoalkylalkoxysilanes 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 (NH₄F). The reaction of APTES with the addition product of succinic or glutaric anhydride with glycerol dimethacrylate results in the formation of new dimethacrylate‐functionalised 3‐amidopropyltriethoxysilanes. The hydrolytic condensation of these silanes was carried out in the presence of 0.5 M HCl. The hydrolysis and condensation of the silanes have been studied by ²⁹Si 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.