Synthesis and characterization of aliphatic amine co-initiator with different chain length for photopolymerization of dimethacrylate

Four kinds of aliphatic amines co-initiator with different chain length were synthesized via Michael-Addition reaction based on aliphatic amine and methyl acrylate. The addition products were characterized by Fourier transform infrared (FT-IR) and 1H NMR spectroscopy. UV–vis absorption and fluorescence spectroscopy were employed to investigate the photophysical process of combination of camphorquinone (CQ) and the newly synthesized amine. The activity of amine co-initiator was investigated by real-time infrared spectroscopy (RTIR). The results showed that the aliphatic amine with different chain length had no effect on the photoinitiation quantum yield of CQ and the formation of amine free radical. The double bond conversion and the rate of photopolymerization increased as the increase of amine concentration. Although the rate of photopolymerization had a slight decrease with the increase of chain length of aliphatic amine, it had only minor effect on the double bond conversion.