Crosslinking kinetics of methyl and ethyl (α-hydroxymethyl)acrylates: effect of crosslinker type and functionality

Photopolymerizations were carried out using monofunctional monomers methyl or ethyl-(α-hydroxymethyl)acrylate (MHMA and EHMA, respectively) with multifunctional crosslinkers. The effect of crosslinker type (acrylate versus methacrylate) and functionality (di-, tri-, tetra- and penta/hexaacrylates) on polymerization rates and conversions were investigated. RHMA systems (monomer plus crosslinker) reached very high conversions (70–83%) for all systems with the exception of dipentaerythritol penta/hexaacrylate systems. Network Tg played an important role in final conversions with dipentaerythritol penta/hexaacrylate and pentaerythritol tetraacrylate, while EHMA (with a lower Tg) went to higher conversions than MHMA.