Kinetic study of free-radical polymerization of multifunctional acrylates and methacrylates

摘要

The conversion profiles of ultraviolet-induced polymerization of di-, tri-, and tetraacrylate and of di-and trimeth-arcylate monomers were measured by in-situ Fourier Transform Infrared (FTIR) spectroscopy. The effects on final conversion of functionality, monomer type (acrylate vs. methacrylate), photoinitiator concentration, light intensity, radiation wavelength, and film thickness were investigated. The trends in final conversion correlate with three features of the conversion profiles: (1) nominal reaction rae, (2) conversion before the onset of deceleration, (3) conversion after the onset of deceleration. The results suggests three important strategies to optimize reaction kinetics. The first, as proposed by Kloosterboer, is to raise reaction rate. The second is to postpone onset of deceleration. The third is to provide conditions so that the growing network is as open and flexible as possible.