Electron paramagnetic resonance (EPR) and electron and nuclear double resonance (ENDOR) characterization of radicals produced during the photopolymerization of multifunctional (meth)acrylate monomers

摘要

The electron paramagnetic resonance (EPR) spectra obtained from radicals produced during the photopolymerization of multifunctional acrylic and methacrylic monomers have been interpreted by taking into account the EPR line-broadening due to dynamic exchange between two conformations of the β-methylene groups and a spin-spin dipolar interaction between radicals trapped in rigid regions of the polymer. From ~1H matrix electron and nuclear double resonance (ENDOR) spectra the distance between the radical center and the surrounding shells of protons can be estimated.