The phase behavior and thermal stability of blends of poly(styrene‐co‐methacrylic acid)/poly(styrene‐co‐ 4‐vinylpyridine)

Abstract

ABSTRACT:The hydrogen bonding and miscibility behaviors of poly(styrene-co-methacrylic acid) (PSMA20) containing 20% of methacrylic acid with copolymers of poly(styrene-co-4-vinylpyridine) (PS4VP) containing 5, 15, 30, 40, and 50%, respectively, of 4-vinylpyridine were investigated by differential scanning calorimetry, thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR). It was shown that all the blends have a single glass transition over the entire composition range. The obtained T g s of PSMA20/PS4VP blends containing an excess amount of PS4VP, above 15% of 4VP in the copolymer, were found to be significantly higher than those observed for each individual component of the mixture, indicating that these blends are able to form interpolymer complexes. The FTIR study reveals presence of intermolecular hydrogen-bonding interaction between vinylpyridine nitrogen atom and the hydroxyl of MMA group and intensifies when the amount of 4VP is increased in PS4VP copolymers. A new band characterizing these interactions at 1724 cm À1 was observed. In addition, the quantitative FTIR study carried out for PSMA20/PS4VP blends was also performed for the methacrylic acid and 4-vinylpyridine functional groups. The TGA study confirmed that the thermal stability of these blends was clearly improved.

Miscibility and specific interactions in blends of poly(4‐vinylphenol‐co‐methyl methacrylate)/poly(styrene‐co‐4‐vinylpyridine)

“…These changes reveal, in fact, that a new contribution corresponding to associated pyridine rings when the hydrogen bonds are formed between hydroxyl groups of PVPhMMA and nitrogen atom of pyridine in PS4VPy30. It must be noted that the similar phenomena have been observed very recently in blends of PS4VPy and poly(styrene‐ co ‐methacrylic acid) which this band was attributed to associated pyridine 25. Moreover, we have not observed the formation of any pyridinium ion for all systems.…”

Improving the barrier character of polylactide/phenoxy immiscible blend using poly(lactide‐co‐ɛ‐caprolactone) block copolymer as a compatibilizer

“…From a thermodynamic point of view the miscibility of the blend depends basically on the mixing enthalpy, since the entropic contribution is very small and hence is negligible. In general, favorable specific interactions between polymers are needed to guarantee the miscibility of the blend …”

Miscibility and Hydrogen Bonding in Blends of Poly(4-vinylphenol)/Poly(vinyl methyl ketone)

“…For all compositions, the values of Tg, reveal clearly that these blends are able to form interpolymer complexes and confirm which was observed during the preparation of solutions. In addition, the intensity of these interactions with the content of the interacting species in the polymeric chains was qualitatively estimated from the Tg-composition curve displayed in Figure 2 and described by the Kwei equation [9]…”

“…In blends with less than 30 mol% VP content in PS4VP copolymers, a heterogeneous phase is observed and evidenced by the apparition of two Tgs. However, in the copolymers, PS4VPy, containing more than 30 mol% of vinyl pyridine in PS4VPy, this miscibility or complexation is also evidenced by differential scanning calorimetry (DSC), where a single Tg was detected for each composition of the blends [9].…”