Showing papers by "Vladimir A. Izumrudov published in 1982"

Substitution reactions in ternary systems of macromolecules

Abstract: Substitution reactions were investigated on a macromolecular system containing two different types of poly-anions, namely sodium polymethacrylate (A), sodium polyethylene sulphonate (B), and the poly-cations of poly-4-vinyl-N-ethylpyridinium bromide (C). The reaction was carried out by adding to the water-soluble non-stoichiometric poly-electrolytic complex (PEC) portions of the competing polymer: PEC(AC) +B⇆PEC(BC)+A (1). Reaction (1) can have two mechanisms depending on the reaction conditions; firstly dissociation of PEC(AC) will cause the C-parts to enter the solution where their bonding of the B macromolecules will yield PEC(BC), and secondly by an electrostatic reaction of the B-parts with the ionic groups of C present in the defects (loops) of PEC(AC) to form mixed ternary PEC which are then transformed to PEC(BC) due to phase-separation of the solutions. Variation of the reaction (1) conditions (addition of a low mol.wt. electrolyte, a change of the length of the polymeric reagents, etc.) can result in an effective control of the substitution route in one or the other direction. The general validity of the process types described is shown.