Binary blends of polyamide 6 with aliphatic polyketone: the compatibility analysis of polymer components

Abstract

The compatibility and interactions of polyamide 6 (PA6) and aliphatic polyketone (APK) were studied when they were mixed in a melt by extrusion. Using the relaxation spectrometry (RS) method, it was shown that the studied PA6/ APK blends had one glass transition temperature (Тg) located on the temperature scale between Тg of initial PA6 and APK. It was also found that in these mixtures, the PA6 b-relaxation peak, responsible for the local movement of small-scale structural units of the main chain and side branches, was socialized with the b-peak of APK. On this basis, conclusions were drawn about the compatibility of PA6 and APK at the segmental and small-scale level. The mutual influence of polymer components of PA6/APK blends on the dynamic shear modulus and the zG3 criterion is shown. The DSC analysis has revealed a slowdown in the crystallization of PA6 and APK in their blends, which is probably due to the formation of extensive interfacial (transitional) layers in the PA6/APK blend, in which crystallization of polymer components is hindered due to intermolecular interactions. The analysis of the IR-spectra in the range of 3000–3800 cm–1 has made it possible to establish the formation of hydrogen bonds between the polyamide –NH-groups and carbonyls –C=O, being part of APK, which contributes to an increase in the compatibility of the polymer components of the blend under study.