The viscosity and osmotic pressure of a fraction of poly-2-vinylpyridine have been measured in various solvents, and the parameters concerning the solubility of this polymer, that is, the osmotic have been obtained: poly-2-vinylpyridine has a solubility parameter of ca. 10.4 (cal./cc.)1/2 and acts as an electron donor. As a result of the specific interaction between a solvent and the pyridine nitrogen of this polymer, the solvent power is greater in an acidic solvent and smaller in a basic than would be expected from the solubility parameter alone. An especially strong interaction between poly-2-vinylpyridine and aliphatic alcohols, chloroform and nitroethane has been observed and its nature has been discussed.
The viscosity, osmotic pressure and light-scattering of a series of 14 fractions of poly-2-vinylpyridine in various solvents have been measured. The following results have been obtained: The constants, Kw′ and v, in the Mark-Houwink equation have been determined for the solutions of: (a) 92.01 weight per cent ethanol, (b) methanol, (c) dimethylformamide, (d) benzene and (e) dioxane as follows:
(a) [η]=1.22×10−4Mw0.73 (d) [η]=1.70×104Mw0.64
(b) [η]=1.13×104Mw0.73 (e) [η]=3.09×104Mw0.58
(c) [η]=147×10−4Mw0.67
The molecular weight of the polymers ranged from 3.4×104 to 93×104, while the viscosity was measured at 25±0.01°C. The constant, K′ in the Mark-Houwink equation in the case of a homogeneous molecular weight has been calculated assuming the exponential- and logarithmic normal-type molecular weight distribution functions for each fraction. The Flory constant, K, defined as [η]θ=KM1⁄2 has been found by the method of Fixman and Krigbaum to be: (8.7±1.0)×10−4 at 25°C. The K value has also been found to be (9.1±1.1)×104 by measuring the intrinsic viscosity in benzene at the θ-point, 16.2°C. The short range interactions of this polymer have also been discussed.
The miscibility behavior of poly(4-hydroxystyrene) (PHS) with poly(4acetoxystyrene)(PAS) was examined by differential scanning calorimetry and Fourier-transform infrared spectroscopy. The PHS-PAS blend system was judged to be miscible on the basis of the appearance of each single, composition-dependent glass transition temperature for the blend. On the other hand, infrared absorption bands attributed to various inter-and intramolecular hydrogen-bonding interactions were identified. Especially, the direct evidence has been obtained for hydrogen-bonding interactions between the hydroxyl group of PHS and the carbonyl group of PAS. The relative strength of these interactions was found to be weaker than those of inter-and intramolecular hydrogen-bonding interactions in pure PHS. Furthermore, the lower critical solution temperature behavior was observed for these blends. KEY WORDS Poly(4-hydroxystyrene) I Poly(4-acetoxystyrene) I Lower Critical Solution Temperature I Phase Diagram 1 Glass Transition Temperature I Polymer Miscibility I Polymer Blends I
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.