Monomer reactivities and kinetics in radical copolymerization of hydroxystyrene derivatives and tert-butyl (meth)acrylate

Monomer reactivity ratios in radical copolymerization of 4-hydroxystyrene derivatives with tert-butyl acrylate and methacrylate have been determined by nonlinear regression as well as by the Kelen-Tudos graphic method. The hydroxystyrene derivatives employed in the study included 4- and 3-hydroxystyrenes, 4- and 3-acetoxystyrenes, and 4-tert-butoxycarbonyloxystyrene. The electron-rich 4-hydroxystyrene is unique as its copolymerization with the electron-deficient acrylate monomers is more alternating. The simulation of the copolymerization on the basis of the reactivity ratios has been shown to fully describe the copolymerization behavior and copolymer structures. The kinetics of radical copolymerization of 4-acetoxystyrene with tert-butyl (meth)acrylate has been studied in detail using a gas chromatographic procedure and also by in situ 1H NMR spectroscopy. The kinetics behavior has shown an excellent agreement with the computer simulation of the copolymerization using the reactivity ratio values determined on the basis of the terminal model.