Preparation and XPS surface chemical analysis of PS/PU nanocomposites

Abstract

Aqueous emulsions of anionic polyurethane ionomers, based on polypropylene glycol as soft segment, isophorone diisocyanate as diisocyanate, dimethylolpropionic acid as chain extender and potential ionic center, and triethylamine as neutralizer, were synthesized. They were mixed with styrene monomers to prepare polystyrene-polyurethane (PS/PU) nanocomposites by an evocator. The sizes and distributions of the particles were measured by dynamic light scattering, and the microstructure of the nanocomposites was observed by transmission electron microscope. X-ray photoelectron spectroscopy (XPS) was used to study the surface characterization of anionic PU and PS/PU nanocom posites. It could be found that the nanoparticles of PU could encapsulate the styrene monomers effectively and the leakage type of every element in PU was not affected by the introduction of Ps. There were more hard segments on the surface of crosslinking PS/PU nanocomposites because of the formation of crosslinking structure and interpenetrating polymer network between PU and PS. © 2006 Wiley Periodicals, Inc.