Acid and base sites of the surface of cellulose nitrates

The distribution of adsorption sites with repsect to the acid-base type and intensity on the surface of cellulose nitrates with different degrees of substitution was studied by the indicator method with spectrophotometric determination of the amount of sites. Acid-base sites capable to act as active sites of adhesion interaction on the polymer surfaces were determined. All the surfaces studied are bifunctional and contain both base and acid sites, with the acid sites prevailing. The aqueous medium influences the activity of some of the revealed sites: Lewis base site (-NO2) with pK (a) = 9.9 and one of the Bronsted acid sites (CH) at the C(6) carbon atom. The results obtained can serve as a basis for understanding the mechanism of adhesion interaction on the phase boundary with cellulose nitrate as one of the phases.