Blends of poly(mono n-alkyl itaconates) with tertiary polyamides: Specific interactions and thermal degradation

Abstract

The specific interactions in blends of poly(mono-n-alkyl itaconate)s with two tertiary polyamides, the poly(N,N-dimethylacrylamide) (PDMA) and the poly(ethyloxazoline) (PEOX), were studied. Hydrogen bonding between carboxylic acid groups of poly(mono-n-alkyl itaconate)s and carbonyl groups of PDMA and PEOX was found. The interassociation extent was measured by spectral fitting of the Amide I band and reveals a loss of interassociating ability in blends with PDMA as the length of the size group of the poly(mono-n-alkyl itaconate) increases, while in blends with PEOX the interassociation degree remains constant for a given composition. This different behavior is attributed to the larger interspacing between vicinal carbonyl groups in PEOX. Spectral changes upon heating showed an increase of thermal stability of the polyacid in the blends, larger in blends with PDMA than PEOX. These changes are explained in terms of the hydrogen bonding and the rigidity of the system. Finally, the ratio of absorption coefficients for the Amide I band was obtained.