Complexation of poly(monobenzyl itaconate) and poly(N-vinyl-2-pyrrolidone) in dilute solution, 2. Influence of variables involved in sample preparation

Abstract

Upon mixing dilute solutions of poly(monobenzyl itaconate) (PMBI) and poly(N-vinyl-2-pyrrolidone) (PVP) in methanol, a soluble interpolymer complex is formed whose properties depend on the method employed to prepare the sample. It was found that the local concentration of the polyacid is the controlling factor. Depending on that concentration, a metastable polymer complex is formed which turns to equilibrium upon sonication. Cooling or heating and aging time have a minor effect. The turbidity of the polymer complex depends on the polyacid concentration to the power ν (at constant polybase/polyacid ratio). For the metastable complex, ν ≈ 2, typical of week polymer complexes. Changes in turbidity are accompanied by a decrease in ν. In the equilibrium state, ν ≈ 1,5, a value being more typical of strong complexes.