SOLUTION AND ADSORPTION PROPERTIES OF VINYL ALCOHOL/VINYL ACETATE COPOLYMERS

The properties of dilute solutions of GH20, an 88% hydrolysed vinyl alcohol/vinyl acetate copolymer (PVA), have been studied by various techniques and the results interpreted in terms of the conformational changes proposed by N.J. Crowther and D. Eagland (J. Chem. Sec: Faraday Trans. 1, 82 (1986) 2791). Viscometric studies on a range of 88% hydrolysed PVAs dissolved in water yielded the solvency for this system, and further studies showed how the solvency varied with the addition of various concentrations of aqueous potassium chloride to the solution, after allowances were made for polydispersity. The behaviour of aqueous solutions of mixtures of polydisperse PVAs is contrary to the predicted behaviour for homopolymers, but can be explained in terms of the adsorption mechanism described by R.A. Croot, A.R. Goodall and S.D. Lubetkin, Colloids Surfaces, 49 (1990) 351.