VISCOSITY BEHAVIOR OF POLY(ETHYL METHACRYLATE) IN THE ETHYL ACETATE TERT-BUTANOL BINARY MIXTURE - TOTAL AND PREFERENTIAL ADSORPTION/

The behaviour of poly(ethyl methacrylate) (PEMA) in the ethyl acetate (1)/tert-butanol (2) binary mixture is studied by laser light scatteri ng, differential refractometry and viscometry. Ethyl acetate is a solv ent for the polymer and tert-butanol is a precipitant. Preferential ad sorption of tert-butanol up to 15% alcohol in the binary mixture is ob served, ethyl acetate being preferentially adsorbed in the macromolecu lar coil at higher percentage of alcohol in the solvent mixture. Total adsorption of PEMA is independent of the amount of tert-butanol in th e solvent. Various theoretical expressions for the preferential and to tal adsorption coefficients are used; their agreement or disagreement with the experimental results is explained on the basis of polymer-sol vent interactions.