Sequential photo-thermal curing of (meth)acrylate-epoxy thiol formulations

In this work, a novel dual-curing procedure has been developed. It is combination of first radical UV-initiated thiol-(meth)acrylate reaction, followed by second thermal thiol-epoxy step catalysed base. Since (meth)acrylates can lead to homopolymerization mechanism, the amount thiol be optimized reach cross-linked materials with Tgs above room temperature and good mechanical performance. should considered, that if in intermediate too low, epoxy take place during step. The use glycidyl methacrylate trifunctional meth (acrylates) allows system gel 1st stage avoids possible dripping or exudation free monomers storage materials. Moreover, compound reacts both stages acting as covalent coupling between networks. We selected trimethylolpropane tris(3-mercaptopropionate) thiol, 2,2-dimethoxy-2-phenylacetophenone UV initiator 1-methylimidazole base catalyst. curing evolution was studied DSC FTIR. All obtained were characterized thermogravimetry, thermomechanical analysis tensile tests.