Novel miscible blends of poly(p-dioxanone) with poly(vinyl phenol)

Poly(p-dioxanone) (PPDO) has been blended with poly(vinyl phenol) (PVPh) and the PPDO/PVPh blends have been investigated using DSC, FTIR and POM. According to the single Tg criterion, miscibility has been found in the whole composition range for the blends obtained by solvent casting from dioxane solutions. The dependence of the Tg on composition shows negative deviation from the Fox equation. The interaction parameter, obtained from melting point depression analysis, χ12 = −1.0, confirms a thermodynamically miscible blend. Specific interactions have been analyzed by FTIR. The OH stretching region of PVPh indicates that upon addition of PPDO the hydroxyl–hydroxyl autoassociation interactions are mainly replaced by hydroxyl–carbonyl interassociation contacts, in detrimental of the possible hydroxyl–ether interactions. The carbonyl stretching region of pure PPDO is sensitive to intramolecular ether-ester interactions occurring in the oxyethanoate structures (–O–CH2–CO–O–) present along the PPDO chain. The –O–CH2–CO–O– structure presents only two minimum energy conformations, trans and cis, resulting in two different absorptions in the Cdouble bond; length as m-dashO stretching region located respectively at about 1757 and 1732 cm−1. Blending with PVPh promotes two new contributions red shifted by about 23 cm−1 relative to the “free” Cdouble bond; length as m-dashO components. Finally, POM analysis shows that the addition of PVPh to PPDO significantly decreases the crystallization rate of PPDO.