Characterization of chitin-based polymer hybrids by temperature-programmedanalytical pyrolysis techniques. 2. Chitin-graft-poly(2-methyl-2-oxazoline)/poly(vinyl alcohol) blends

Chitin-graft-poly(2-methyl-2-oxazoline)/poly(vinyl alcohol) (PVA) blends we re characterized by means of analytical pyrolysis techniques such as temper ature-programmed pyrolysis-mass spectrometry (TPPy-MS), TPPy-gas chromatogr aphy (TPPY-GC) and Py-GC mainly in terms of their miscibility and the site of the intermolecular interaction. The thermal degradation of the chitin de rivative/PVA Mends took place apparently in two stages reflecting the degra dation of both constituent polymers. However, peak-top temperatures for bot h degradation stages changed as a function of blend composition; the first degradation stage, mostly corresponding to the dehydration of PVA, shifted to higher temperatures when the chitin derivative content is increased in t he blend. Although the yields of 2-butenal from the PVA moiety increased by blending the chitin derivative, those of acetamide and N-ethylacetamide fr om the chitin derivative moiety exhibit an opposite trend. These temperatur e-shifts and the variations in the yields of the pyrolysis products suggest ed that intermolecular interactions might be contributing to a differing ex tent as a function of the blend composition. Moreover, the observed degrada tion behaviors for the chitin derivative/PVA blends showed the opposite tre nd for the case of the chitin derivative/PVC blend system previously invest igated. Thus, the observed degradation mechanisms of this blend system were discussed by comparison with those for the chitin derivative/PVC blend sys tem.