On-line measurement of monomer concentration in UV photopolymerization using a quartz crystal resonator

In spite of the importance of monomer concentration measurement in polymerization, it is difficult to measure the concentration in thin film polymerization, such as the UV photopolymerization of acrylates. A small device, a quartz crystal resonator, has been applied to the measurement of monomer amount in the UV photopolymerization of trimethylolpropane triacrylate with an initiator of 2-ethylanthraquinone. The resonant resistance of the resonator is converted to the monomer concentration using an empirical relationship. The measurement results indicate that the proposed technique is effective for determining the monomer concentration. The simplicity and ready availability of the proposed application have been proven experimentally.