SIZE-EXCLUSION BEHAVIOR OF POLYMERS IN AMIDE SOLVENTS .1. ELUTION CHARACTERISTICS OF ACRYLONITRILE POLYMERS IN N,N-DIMETHYLFORMAMIDE

The abnormal behavior of acrylonitrile polymers shown by size exclusion chromatography (SEC) in N,N-dimethylformamide (DMF) was investigated by using model polymers having variable degrees of sulfonated moieties as electric charged groups. The unexpected small retention volume and very high UV absorption at 280 nm were observed in the case of the samples with ionic sulfonate groups even in very small amounts, as chain ends. The abnormal behavior was confirmed to be due to impurities of DMF decomposition which interact with charged groups in the polymers.