Effect of phenolic compounds on the primary processes of photopolymerization

The photopolymenzation of acrylate resins on wood surfaces suffers from retardation and inhibition
effects due to phenolic derivatives present at the interface. In this paper, the global effect of eugenol
on the polymerization process is recorded by differential scanning calorimetry and photocalorimetry
(DSC/DSP). A comparison between a direct photocleavable initiator like dimethyiphenylacetophenone (DMPA) and a two-component system like benzophenone/ N-methyldiethanolamine (BP/MDEA) suggests that the retardation effect observed in the latter case is due to the interaction between phenols and the triplet state of BP. Subsequently, nanosecond transient absorption (NTA) spectroscopy is used to study the influence of several phenols on the primary processes. Some EPR experiments are also made on wood samples to confirm in situ the photoreduction process.