Preparation, properties, and applications of acrylic–polyurethane hybrid emulsions in extinction electrophoresis

Abstract

ABSTRACTAqueous acrylic–polyurethane hybrid emulsions (PUA) were fabricated by semibatch emulsion copolymerization using a mixture of acrylic (AC) monomers in the presence of an isocyanate terminated polyurethane (PU). The effects of PU content on the morphology of the hybrid emulsions and film properties were here investigated in detail using FT‐IR, UV, TEM, and SEM. TEM images clearly showed that hybrid emulsions exhibited a core‐shell structure before neutralization. However, after neutralization with N,N‐dimethylethanolamine, the typical particles exhibited phase inversion, producing particles with irregular hemispheres shapes and diameters about 0.5 μm. SEM images showed that the film surface became rougher as PU content increased, peaking at 10 wt %, the gloss of this film was 23.1 (60°). The UV transmittance spectra of the PUA hybrid emulsion within a wavelength range 700–200 nm decreased as PU content increased. This was consistent with the changes in the surface roughness of the film. Electrophoresis took place on an aluminum alloy surface and the product was dried at 120°C. The film exhibited excellent mechanical performance due to curing reaction between the NCO group on PU and hydroxyl group on the AC copolymer. The gloss of the film was found to be as low as 4.0 after electrophoresis testing. These films may be useful in practical extinction electrophoresis. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40078.