SOME PROPERTIES OF AQUEOUS-SOLUTIONS OF POLY[(MALEIC ACID)ALT-(P-SULFOSTYRENE, STYRENE)]

By sulfonation of poly[(maleic anhydride)-alt-styrene] in mild conditi ons (SO3/triethylphosphate, 298 K) a series of poly[(maleic acid)-alt- (p-sulfostyrene, styrene)] have been prepared having the same average chain length but various content of p-sulfostyrene units (from 18 to 8 3 mol %). A behavior of diluted aqueous solutions of two polyelectroly te series (polyacids and Na-salts) has been compared, using viscosimet ric, conductometric, and potentiometric measurements, and taking into consideration the degree of sulfonation and the kind of counterions (H +, Na+). Although the values of intrinsic viscosities [eta] and equiva lent conductivities lambda of two copolymer series belong to two diffe rent ranges, in polyacid series they increase with increasing the degr ee of sulfonation, while in Na-salt series they decrease. According to the potentiometric titration and reduced viscosity data, the intensit y of conformational. chain transitions of sulfonated polycids also dec reases with increasing the degree of sulfonation. The noticed effects are related to structural characteristics of functional copolymers, gr adual increase of a charge density along the chains, lower mobility of the Na-salts, and to a diminished hydrophobicity of styrene units due to sulfonation. (C) 1995 John Wiley & Sons, Inc.