Hydrodynamic properties of poly(1‐vinyl‐2‐pyrrolidone) molecules in dilute solution

Abstract

AbstractThe translational diffusion coefficient D0, the sedimentation coefficient S0, and the intrinsic viscosity [η] of samples and fractions of poly(1‐vinyl‐2‐pyrrolidone) were measured in a 0,1 M solution of sodium acetate in the molecular weight range 2 ≤ M · 10−3 ≤ 2200. For M > 4 · 104 the following relationships were obtained: [η] = 8,86 · 10−5 · M0,74, D0 = 2,42 · 10−4 · M−0,58, and S0 = 2,14 · 10−15 ·. M0,42. For M < 4 · 104 the corresponding relations are [η] = 5,0 · 10−4 · M0,56, D0 = 1,29 · 10‐4 · M−0,52 and S0 = 1,15 · 10−15 · M0,48. The hydrodynamic invariant is A0 = (3,2 ± 0,25) · 10−17 J · K−1 · mol−1/3 and the sedimentation parameter βs = (1,3 ± 0,17) · 107 mol−1/3. The temperature coefficient of the intrinsic viscosity is negative, viz. Δ ln[η]/ΔT = −6,3. 10M−3 K−1. The evaluation of the length of the Kuhn segment A and the hydrodynamic diameter d of chains representing the molecules of PVP in solution was conducted on the basis of the theory for the hydrodynamic properties of a wormlike necklace taking into account the excluded volume effects. The values of A agree with those obtained from the Burchard‐Stockmayer‐Fixman and Cowie‐Bywater equations, A = (2,1 ± 0,3) nm and d = (0,5 ± 0,13) nm.