Blends of Poly(vinyl Pyridine)s and Two Dihydric Phenols: Thermal and Infrared Spectroscopic

The miscibility behavior in blends containing poly(4-vinyl pyridine) (P4VPy) and poly(2-vinyl pyridine) (P2VPy) as polymer components and the dihydric phenols 4,4’-thiodiphenol (TDP) and 4,4’-methylendiphenol (MDP) as low molecular weight compounds (LMWC), was studied by Differential Scanning Calorimetry (DSC) and Fourier Transform Infrared Spectrophotometry (FTIR) as main analytical techniques. The glass transition of P4VPy and the melting of TDP and MDP, were found to be significantly affected when the compounds were blended. This result was attributed to the miscibility between them, as a direct consequence of the specific interactions between the blend components. FTIR was used to investigate these interactions. The formation of intermolecular hydrogen bonds between the pyridine nitrogen atoms and the hydroxyl groups of TDP and MDP were discovered. When P2VPy was the macromolecular component, a difference was observed in the DSC behavior, which was attributed to a steric hindrance effect. Thermogravimetric and viscometry analysis were also used as additional techniques to complement the FTIR and DSC measurements performed.