Dual Curing Systems Based on UV curing and Alkoxysilane Group Condensation

A study was performed on dual curing systems based on UV curing of reactive unsaturations (acrylic double bonds) and successive alkoxysilane group condensation. The systems were obtained by mixing a typical epoxy acrylic resin with different amounts of monomers containing alkoxysilane groups (3‐methacryloyloxypropyltrimethoxysilane, MEPTS, and 3‐mercaptopropyltrimethoxysilane, MPTS) in the presence of a photoinitiator and a condensation catalyst. After UV curing, the kinetics of the alkoxysilane group condensation was followed by Fourier Transform Infrared Spectroscopy (FTIR) analysis at different temperatures and water vapour pressures. Higher condensation rates were obtained in the systems containing MPTS with respect to the MEPTS system. Also the adhesion on glass sheets was better in the presence of MPTS with respect to MEPTS. These results were attributed to the different structures and to the different crosslinking density obtained in the presence of the two monomers. Wetting tension, Attenuated Total Reflectance (ATR‐FTIR) and X‐Ray Photoelectron Spectroscopy (XPS) measurements are in agreement with these conclusions.