UV-cured hyperbranched polyester polythiol(H20-SH)-epoxy acrylate networks: Preparation, thermal and mechanical properties

A hyperbranched polyester polythiol(H20-SH) was synthesized and characterized by FTIR spectral analysis, 1H-NMR spectral analysis and GPC analysis. H20-SH was added into the formulation of UV-curable epoxy acrylate networks based on thiol-acrylate chemistry. The effects of H20-SH on polymerization kinetics, thermal and mechanical properties of thiol-epoxy acrylate networks were investigated by Real-time infrared spectroscopy, dynamic mechanical analysis (DMA), thermogravimetric (TGA), tensile test and water absorption characterization. Results show that epoxy acrylate resin with the addition of H20-SH massively reduces oxygen inhibition, improves the uniformity of cured films and enhances the tensile strength of the films. However, the thermal stability and glass transition temperature (Tg) decreases with the increasing amount of H20-SH.