Photochemical and photopolymerization study of 2,6‐dihalogen derivatives of p‐nitroaniline in the presence of N,N‐dimethylaniline as a bimolecular photoinitiator system

Steady‐state photolysis at 365 nm has been employed to carry out a structure—reactivity investigation of the 2,6‐dihalogen derivatives of p‐nitroaniline (pNA). Detailed studies of the spectroscopy of these molecules were accomplished. Photoreduction behavior of the 2,6‐dihalogen derivatives of p‐nitroaniline in the presence of N,N‐dimethylaniline (DMA) has been analyzed. The efficiency of these compounds as photoinitiators was studied by following the polymerization kinetics of the lauryl acrylate (LA) monomer by differential scanning photo‐calorimetry (Photo‐DSC) under aerobic and anaerobic conditions. Using size exclusion chromatography (SEC) analysis of the polymers their number‐average molecular weights, the number‐average degree of polymerization, and the length of the kinetic chain were determined and information on the nature of the end‐chain groups and the chain‐transfer behavior of these photoinitiators systems were obtained. The polymerization activity of the 2,6‐dihalogen derivatives of pNA proved to be higher than those obtained with conventional aromatic ketone photoinitiators.