Swelling behaviour of a non-ionic poly(N-vinyl-2-pyrrolidone) gel in a linear poly(acrylic acid) solution

Abstract

SUMMARY:The swelling behaviour of a non-ionic poly(N-vinyl-2-pyrrolidone) hydrogel in a linear poly-(acrylic acid) solution upon the influence of chain length, pH, ionic strength, and water/dimethyl sulfoxide composition was studied. The sharp shrinkage of the gel volume within a narrow range of polyacid concentration takes place as a result of the formation of an intermacromolecular gel-polymer complex on the base of hydrogen bonding. According to X-ray diffraction this complex is amorphous. The formation of the gel-polymer complex is a long term process and the system reaches equilibrium within 48 h. The swelling behaviour strongly depends on the chain length of the polyacid whereas it does not depend on the ionic strength. With increasing pH value and changing water/dimethyl sulfoxide composition the gel reswelling is induced. The complex formation with poly(acrylic acid) occurs in the same way for linear and crosslinked poly(N-vinyl-2-pyrrolidone).

Interrelation of Hierarchy of Structures at Comparison of Linear and Cross-linked Polymer Compounds

“…One can see that the scale of the measuring values is the only difference between the presented curves. A similar result was given in [7]. In this paper the systems synthesized on the base of poly(N-vinyl-2-pyrrolidone) (1 -cross-linked, 1alinear) and poly(acrilic) acid (2) were investigated.…”

“…One can suppose that in the case described in [6] Katchalsky and Lifson's theory is applicable. Oppositely, in the last cases [5,7] some effects connected with the electrostatic interactions take place. In order to investigate this problem let us consider the next systems: poly(ethylenglicol) in CH 3 OH -CCl 4 intermixture and poly(acrilic) acid in NaCl (0.1N) -C 4 H 8 O 2 intermixture.…”

Polyelectrolyte complexes formed by hyperbranched poly(sulfone‐amine) hydrochlorate and poly(sodium acrylate)

“…It has been well realized that if no specific interactions exist between two kinds of different polymers, the random coils of component polymers isolate from each other in dilute solution 24. On the other hand, when polymer–polymer interacts with each other in solution, the hydrodynamic volume of polymer chains can be changed.…”

Conformational changes and swelling behavior of poly[(methacrylic acid)-co-(methyl methacrylate)] gel in solution of linear poly(ethylene glycol)

“…Meanwhile, the interpolymer complex formed by a network with a small mesh size must have first developed on the surface layer. 2,23 This will prevent further interactions of the segments not involved in the complexation process. The above reasons explain that the m value sharply decreases with increasing cross-linking density of the network as shown in Fig.…”