A differential scanning calorimetric investigation of the solution properties of Poly(styrene : isoprene : styrene) block copolymers

Abstract

D.s.c. heating curves have been obtained from solutions of a series of well characterized poly-(styrene : isoprene : styrene) triblock copolymers. In the preferential solvent, methylcyclohexane, endotherms and/or exotherms (depending on composition) were observed from all polymers with composition in excess of 10% polystyrene. These phenomena were not observed from solutions of the copolymers in good or poor solvents for both kinds of segments. An explanation is given in terms of gel formation and polymer aggregation.