ANALYSIS OF SURFACE ALDEHYDE FUNCTIONS ON SURFACTANT-FREE POLYSTYRENEPOLYACROLEIN LATEX/

The semicontinuous surfactant-free synthesis of a core/shell sytrene/a crolein latex and its analysis for surface aldehyde functions are desc ribed. A colorimetric assay based on reaction with dinitrophenylhydraz ine is compared with reduction by tritiated sodium borohydride and int egration of aldehyde peaks in the proton NMR spectrum of the dissolved polymer. X-ray photoelectron spectroscopy confirmed the surface locat ion of the aldehyde functions and the analytical reaction products. Th e three assay procedures were in reasonable agreement, suggesting all the aldehyde functions were accessible to aqueous reagents.