Solutions of poly(2-ethyl-2-oxazoline), PEOX, and poly(2-methyl-2-oxazoline), PMOX, in water and PEOX solutions in several alcohols were characterized by light scattering. The second virial coefficients in water were found to decrease with increasing temperature, reflecting lower critical solution behaviour due to hydrogen bonding. This resulted in negative values of the excess enthalpy Ah ~ and entropy of dilution As E for PEOX and PMOX in water. The magnitudes of Ah E and As E were higher for PMOX than for PEOX. The magnitudes of Ah E and As E for PEOX increased with molecular weight. The second virial coefficients of PEOX in water were systematically lower than in ethanol, isopropanol and n-butanol.
Посилання на статтю:
A light-scattering study of poly(2-alkyl-2-oxazoline)s: effect of temperature and solvent type / C. H. Chen*, J. Wilson, W. Chent, R. M. Davis and J. S. Riffler // Polymer. – 1994. – Vol 35. – P. 3587-3591.