UV curing of photoinitiator-free systems containing bismaleimides and diacrylate resins: bulk and surface properties

UV curing of photoinitiator-free systems containing a bismaleimide and different diacrylates was investigated. Firstly we investigated the copolymerization of a bismaleimide and a polysiloxane diacrylate resin using different monomer ratios. Moreover, a typical diacrylate (bisphenolAdiglycydyletherdiacrylate) (BHEDA) was employed and the bulk properties of the networks were modulated varying the amount of bismaleimide in the photocurable mixture. The curing process was monitored by FTIR and the thermal properties by DSC analyses. Surface properties were changed by addition of small amounts (less than 1 wt.%) of a polysiloxane diacrylate to the bismaleimide/BHEDA 50-50 mol% mixture: notwithstanding the low concentration of the siloxane monomer, highly hydrophobic surfaces were obtained.