Phase separation and surfactant stratification in styrene/n-butyl acrylate copolymer and latex blend films.: 17.: A spectroscopic study

These studies focus on behavior of sodium dioctylsulfosuccinate (SDOSS) surfactant molecules in styrerie/n-butyl acrylate (Sty/n-BA) copolymers and blended latexes. Using a combination of IR and Raman spectroscopic and microanalytical techniques, not only stratification of SDOSS surfactant molecules across latex film thickness can be assessed. but also the effect of latex composition on coalescence can be analyzed. For Sty/n-BA latex copolymers, SDOSS ... H2O, SDOSS ... COOH associations, and free SDOSS are formed at the film-air (F-A) interface and exhibit nonuniform distributions across the film thickness. However, for p-Sty/p-nBA latex polymer blends, SDOSS is distributed uniformly at the F-A interface, and its concentration levels are significantly lower when compared to Sty/n-BA copolymer latexes. These studies show that, while step-scan photoacoustic Fourier transform infrared (SS-PAS FTIR) and attenuated total reflectance (ATR) FT-IR are effective depth profiling methods for latex, films, FT-IR and FT-Raman imaging techniques provide unique analytical facilities far typically nondistinguishable surface latex components.