TRIBLOCK COPOLYMERS IN A SELECTIVE SOLVENT .1. AGGREGATION PROCESS INDILUTE-SOLUTION

Triblock copolymers polystyrene-polyisoprene-polystyrene were studied in dilute solution in a selective solvent, i.e., a nonsolvent for poly styrene and a good solvent for polyisoprene. At a concentration equal to 1.6 x 10(-3) g/cm3 triblock aggregates appear. Elastic and quasi-el astic light scattering experiments, as well as intrinsic viscosity mea surements, performed on these solutions show a loose structure rather than a micellar structure for the aggregates. These experimental resul ts are also discussed from a theoretical point of view.