Glass-transition temperature of a polyacrylate latex film and its water whitening resistance

Polyacrylate latex materials have become a hot area recently in China due to its environmental friendliness. However, the water whitening resistance of the polyacrylate latex products in the market is largely unsatisfactory, which seriously affects the appearance and performance of the latex products. In this work, the effect of glass-transition temperature (T_g) of a polyacrylate latex film on its water whitening resistance was investigated. The light transmittance measurement showed that the higher the T_g of the latex film, the better the water whitening resistance. Atomic force microscope, surface element analysis, static water contact angle measurement, and attenuated total reflection–Fourier transform infrared were used to characterize the accumulation of the emulsifier on the surface of the latex film. It was found that the amount of emulsifier migrated to the surface of the latex film increased with the increase of the T_g of the latex film, that is, the amount of emulsifier remained inside the latex film decreased, thereby reducing its affinity to water. In addition, the higher the T_g of the latex film, the lower the water absorption, also reducing the affinity of the latex film to water. Both work together to improve the water whitening resistance of polyacrylate latex film with higher T_g. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48361.