Blends of Poly (Vinyl Pyridine)s and Two Dihydric Phenols: Thermal and Infrared Spectroscopic Studies. Part Ii

Abstract

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.

Blends of Poly(4-Vinylpyridine) and Dihydric Phenols: Thermal and Infrared Spectroscopic Studies. Part Iii

“…As a result, the crystallinity should lower. We have reported the same behaviour for blends formed by P4VPy, poly(2-vinylpyridine) (P2VPy) and poly(methyl methacrylate-co-methacrylic acid) [P(MMA-co-MA)] as polymer components and 4,4'-thiodiphenol (TDP) and 4,4'methylenediphenol (MDP) as low molecular weight components [33][34] . In all the cases, the observed behaviour suggests some kind of intermolecular interaction between the polymer and the LMWC.…”

“…In both blends a shifting of the polymer Tg to lower values is observed as the LMWC content increases (Figure 3-b). This behaviour, known as the plasticizing effect, has been described for different commercial products 35 and by us in a previous work that studied the blends of poly(4-vinylpyridine) and poly(2-vinylpyridine) with 4,4'-thiodiphenol and 4,4'-methylendiphenol 34 .…”

“…For example, pyridine rings of polyvinylpyridines, typical proton acceptor polymers, suffer evident modifications. The mode corresponding to the deformation of the ring, centred in 993 cm -1 for nonbonded groups, experiments a shift towards higher wave numbers when it forms part of a hydrogen bond, which is attributed to an increase in the stiffness of the associated ring 30,34 . Figure 4 shows the FTIR spectra of the blend A for selected compositions as representative examples.…”

“…In this context, one of the most useful analytical techniques, used in this work, is infrared spectrophotometry as can be observed in a series of studies 1,2,5,[30][31][32] . We have recently reported the results about the miscibilization behaviour of some functionalized vinyl polymers such as poly(2-vinylpyridine) (P2VPy), poly(4-vinylpyridine) (P4VPy) and poly(methyl methacrylate-co-methacrylic acid) [P(MMA-co-MA)] (as polymer components) with some dihydric phenols such as 4,4'-thiodiphenol (TDP) and 4,4'-methylenediphenol (MDP) (as low molecular weight components) 33,34 . The present paper studies the compatibility in blends formed by P4VPy as the polymer component and 4,4'-Biphenol (44BP) and 2,2'-Biphenol (22BP) as LMWCs.…”

Blends of Poly(n-Vinyl-2-Pyrrolidone) and Dihydric Phenols: Thermal and Infrared Spectroscopic Studies. Part Iv

“…In any case, the obtaining of miscible blends is the result of specific interactions between the components. For this, a series of functionalized polymers has been used and reported by different authors 8,12,[23][24][25] as well as by the authors of this work [26][27][28] . Poly(N-vinyl-2-pyrrolidone) is a water soluble functionalized vinyl polymer, physiologically compatible, non-toxic, and colorless 29 .…”