The Temperature Dependence of the Peculiar Behaviour of Poly(N-vinyl-2-pyrrolidone) in Water. Specific Effect or Conformational Transition?

Abstract

Intrinsic viscosity [q], measurements in water at different temperatures were carried out for one fraction of poly(vinylpyrro1idone) (PVP). An anomalous behaviour of [q] at 30°C is observed. The shape of the plot of [q] vs Tseems to indicate that PVP undergoes a peculiar change in water. Values of the partial specific compressibility (LC) for PVP at various temperatures are compared with the intrinsic viscosity results. This anomalous behaviour of [q], can be interpreted in terms of the different amount of hydration and the break of water structure with temperature obtained through the LC values for PVP as function of temperature.