Jr. Quintana et al., MICELLIZATION OF POLYSTYRENE-BLOCK-POLY(ETHYLENE PROPYLENE) IN TOLUENE SOLUTIONS OF POLYSTYRENE/, Langmuir, 12(9), 1996, pp. 2196-2199
The thermodynamics of the micellization process of polystyrene-block-p
oly(ethylene/propylene) in solutions of polystyrene in toluene was stu
died. Toluene is a good solvent for both copolymer blocks, whereas pol
ystyrene and poly(ethylene/propylene) are not compatible polymers. The
influence ofthe polystyrene concentration on the standard Gibbs energ
y, Delta G degrees, enthalpy, Delta H degrees, and entropy, Delta S de
grees, of micellization was investigated. The thermodynamic magnitudes
were calculated from critical micelle temperature and concentration d
ata. The critical micelle temperatures ofthe different micellar soluti
ons were determined by light scattering measurements. All ofthe standa
rd magnitudes of micellization become more negative as the polystyrene
concentration increases, suggesting an increment of medium selectivit
y.