LIQUID ADSORPTION CHROMATOGRAPHY OF STYRENE COPOLYMERS OF METHACRYLATES AND ACRYLATES

Styrene copolymers with methyl, ethyl and n-butyl methacrylate and acrylate were prepared by solution polymerization at a low degree of conversion. These copolymers were separated according to composition by gradient elution using silica gel as the stationary phase and chloroform-ethanol as the mobile phase. The initial mobile phase was chloroform-ethanol (99:1, v/v/) and the final one (93:7, v/v), the composition chaning linearly. Acrylate- or methacrylate-rich copolymers were eluted later and required a higher ethanol content in the mobile phase. The retention volume of the copolymers was influenced by column temperature in such a way that the copolymers tended to be retained in the column longer at high temperatures. The resolution between two adjacent peaks was improved with increase in column temperature. For copolymers having the same styrene content, those having smaller alkyl ester groups tended to be retained in the column longr than those having longer alkyl ester groups at the same column temperature. © 1990.