MISCIBILITY IN BLENDS OF POLY(VINYL ACETATE-CO-VINYL ALCOHOL) WITH POLY(N,N-DIMETHYLACRYLAMIDE)

Miscibility of poly(N,N-dimethylacrylamide) (PDMA) with poly(vinyl ace tate) (PVAC), poly(vinyl alcohol) (PVAL) and poly(vinyl acetate-co-vin yl alcohol) (ACAL copolymers) has been investigated over a wide compos ition range. Differential scanning calorimetry (DSC) results indicate that PDMA is immiscible with PVAC, but is miscible with PVAL and ACAL copolymers in certain range of compositions. The ACAL/PDMA phase diagr am for different copolymer compositions has been determined. The varia tion of the glass transition temperature with blend composition for mi scible systems was found to follow the Kwei equation. Infrared spectro scopy studies of blends reveal the existence of specific interactions via hydrogen bonding between hydroxyl groups in vinyl alcohol units an d the carbonyl group in the tertiary amide, which appear to be decisiv e for miscibility. (C) 1997 Published by Elsevier Science Ltd. All rig hts reserved.