Separation of Styrene - Methyl Methacrylate - Acrylonitrile Terpolymers by Composition Using High-Performance Liquid Chromatography

Separation of styrene - methyl methacrylate - acrylonitrile terpolymers by chemical composition was studied using high-performance liquid chromatography (HPLC). Cross-linked polyacrylamide (PAA) gel or polyacrylonitrile (PAN) gel was used as a stationary phase for normal-phase HPLC and cross-linked polystyrene (PS) gel for reversed-phase HPLC. Each system was based on a solvent gradient, and the separation was governed by an adsorption mechanism. Terpolymers were successfully separated by the cross-fractionation, i.e., the combination of two types of HPLC systems with PAN and PAA columns or PAN and PS columns. The chemical composition distribution (CCD) of a high-conversion terpolymer was analyzed by this cross-fractionation technique with the combination of PAA and PAN columns. The CCD obtained experimentally was reasonably consistent with that of theoretical calculation.