Simultaneous free-radical and addition miniemulsion polymerization: Effect of the chain transfer agent on the microstructure of polyurethane-acrylic pressure-sensitive adhesives

Abstract

The effects of the CTA concentration on polymerization kinetics, polymer microstructure, particle morphology, and adhesive performance of waterborne hybrid PSAs prepared by simultaneous free-radical and addition miniemulsion polymerizations are studied. The development of the microstructure is shown to differ from waterborne acrylic PSAs obtained by free-radical polymerization because of the contribution of the addition reaction, which in turn causes marked differences in the adhesive performance of the final films. A computer simulation is developed to obtain detailed information about the microstructure of PU/acrylic hybrids and to correlate the microstructure with the final adhesive properties. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.