Synthesis and characterization of triptycene type cross-linker and its use in photoinduced curing applications

A novel triptycene type diacrylate cross-linker, triptycene hydroquinone diacrylate (THDA) was synthesized from the reaction of triptycene hydroquinone with acryloyl chloride and characterized. The photocuring behaviour and the reaction kinetics of the synthesized cross-linker were investigated by means of photo-differential scanning calorimetry (photo-DSC) experiments. Formulations containing monofunctional (meth)acrylate monomers, namely glycidyl methacrylate (GMA), 2-hydroxyethyl acrylate (HEA), 2-hydroxyethyl methacrylate (HEMA), and 2-ethylhexyl methacrylate (EHMA), cross-linker, THDA and 2,2-dimethoxy-2-phenylacetophenone (DMPA) as a photoinitiator were irradiated. A conventional cross-linker without triptycene unit such as hydroquinone diacrylate (HDA) was used under the same conditions for comparison. The effects of the structure of the monofunctional monomer and triptycene moiety on the photopolymerization kinetics were evaluated and discussed.