Surface analysis of model latex particles

Abstract

The surface structure of model latex particles, synthesized for the study of latex film formation mechanisms, was investigated by contact angle measurements, surfactant (sodium dodecyl sulfate) adsorption and X-ray photoelectron spectroscopy. Core—shell particles were prepared by an inverted core—shell polymerization. The hydrophilic polymer of the shell was produced first and acted as a seed in the final step where the core was formed. The shell was a styrene/butyl acrylate/methacrylic acid terpolymer containing 10, 15 or 25 wt.% of methacrylic acid. The core was a styrene/butyl acrylate copolymer. Comparison of the surface analysis results obtained on the seed and final core—shell latexes allowed us to draw conclusions on the surface structure of the particles and to discuss the mechanism of the inverted core—shell synthesis. It was demonstrated that the structure of the core—shell particles did not correspond to the one that would have resulted from an ideal inverted core—shell synthesis, but these particles were still suitable for our studies of film formation mechanisms.