Static and dynamic light scattering of maleic acid copolymers

We study aqueous solutions of maleic acid-vinyl acetate alternating copolym ers in a wide range of polymer C and salt C-s concentrations by means of st atic and dynamic light scattering. Depending on C and C-s, the decay of the autocorrelation function of the scattered electric field is characterized by one or two modes of relaxation. This feature allows one to define the di lute and semi-dilute regimes in a diagram C-C-s. The fast mode of relaxatio n has the usual behavior reported for polyelectrolyte solutions. The slow m ode of relaxation can be linked with the occurrence of chain aggregation. T he proposed driving force for the aggregation is the lactonization of the m onomers that decreases their solubility in water. Ultimately a phase separa tion occurs after a time of several weeks that depends on C and C-s. (C) 20 00 Elsevier Science Ltd. All rights reserved.