SURFACE AND INTERFACIAL FT-IR SPECTROSCOPIC STUDIES OF LATEXES .8. THE EFFECT OF PARTICLE AND COPOLYMER COMPOSITION ON SURFACTANT EXUDATION IN STYRENE-N-BUTYL ACRYLATE COPOLYMER LATEX FILMS

Polarized attenuated total reflection Fourier transform infrared (ATR. FT-IR) spectroscopy was used to identify the mobility and surfactant exudation of sodium dioctyl sulfosuccinate (SDOSS) surfactant molecules to the film-air (F-A) and film-substrate (F-S) interfaces in styrene/n-butyl acrylate (Sty/n-BA) latex films. It was found that, depending upon the latex particle composition, the surfactant molecules could be driven to the F-A or F-S interfaces. The primary factors that governed the direction of exudation were the compatibility of the latex components, interfacial film-substrate surface tension, and the chemical composition of the latex particles. Concentration, as well as orientation, of the hydrophilic SO3-Na+ surfactant ends changed as a function of depth and the latex particle composition. (C) 1993 John Wiley & Sons, Inc.