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The reorientational dynamics of dipoles in poly(vinylidene fluoride)/poly(methyl methacrylate) (PVDF/PMMA) blends were investigated by dielectric spectroscopy. Measurements were performed over a wide range of temperature and frequency, and previously unavailable results are reported. Various relaxation processes were identified and their locations assigned to the different morphological regions in PVDF, PMMA, and PVDF/PMMA blends. The development of a relaxation process associated with the imperfections in the crystalline phase was recorded both in pure PVDF and in crystalline blends. An amorphous interphase and a liquid-like amorphous phase are present in pure PVDF, but their relaxation dynamics are dielectrically indistinguishable, giving rise to a single non-Arrhenius relaxation mechanism. In the crystalline blends, however, the interphase is devoid of PMMA, and its relaxation dynamics are readily distinguishable from those of the PVDF/PMMA miscible phase. Interestingly, the relaxation dynamics in the interphase were found to vary as a function of blend composition. Since the relaxation processes are governed by cooperativity, an explanation of our findings is offered in terms of the interactive nature of the relaxation process.

The solubility of poly(ethyl oxazoline) in aqueous solutions was studied. The cloud point temperatures decreased in the presence of sodium chloride but increased by the addition of tetrabutylammonium bromide or dioxane. Solution‐cast films of blends of the polymer and poly(acrylic acid) were miscible, but mutual precipitation occurred in water, methanol, and dioxane. The compositions of the complexes correspond in most cases to simple molar ratios of the interacting groups. The glass transition temperatures of the complexes are higher than the values for blends of the same compositions, and the high values are attributed to hydrogen bonds acting as physical crosslinks. Complex formation also occurs when the polymer is mixed with a styrene‐acrylic acid copolymer and with low weight polymers containing phenol groups.

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