Blends of Poly(vinyl Pyridine)s and Dihydric Phenols: Thermal and Infrared Spectroscopic Studies. Part V

Abstract

Binary blends with poly(4-vinyl pyridine) (P4VPy) 160,000 g/mol and poly(2-vinyl pyridine) (P2VPy) 159,000 g/mol as polymer components and 4,4´-thiodiphenol (TDP), 4,4´-methylendiphenol (MDP), 2,2´-biphenol (22BP) and 4,4´-biphenol (44BP) as low molecular weight compounds (LMWCs), were prepared. Miscibility between the components was analyzed by Fourier Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC). Thermogravimetric Analysis (TGA) and Scanning Electron Microscopy (SEM) were also used as complementary techniques. Hydrogen bonding formation was detected by FTIR due to the increasing of the wave number corresponding to the deformation absorption of pyridine groups in P4VPy and P2VPy. A decreasing of melting points and fusion heats of the LMWCs is observed by DSC, which shows a lower crystallinity level as the blends are richer in the polymer component as a consequence of the intermolecular interaction. A plasticizing effect is also observed by DSC when P4VPy is blended with TDP and MDP; the higher steric hindrance prevents this effect when P2VPy is blended with 22BP and 44BP. Miscible blends were obtained with a moderate trend to a higher interaction degree in blends containing P4VPy. This report is the fifth part of a series of works including polymer-LMWC blends. Variables such as molecular weight increase in P4VPy and steric hindrance in P2VPy have been comparatively analyzed with blends previously reported.