I. Katime et al., MICELLIZATION PROCESS OF DIBLOCK COPOLYME R IN BINARY-MIXTURES OF THETYPE - SELECTIVE SOLVENT GOOD SOLVENT AND SELECTIVE SOLVENT PRECIPITANT, Anales de quimica, 91(3-4), 1995, pp. 184-192
This paper shows the results obtained for the micellization process of
polystyrene-block-poly(ethylene/propylene) in 4-methyl-2-pentanone/2-
chlorobutane and 5-methyl-2-hexanone/2-pentanol binary mixtures. 4-met
hyl-2-pentanona (MIBK) and 5-methyl-2-hexanone (MIAK) behave as select
ive solvent for the PS block copolymer, while 2-chlorobutane and 2-pen
tanol are a good solvent and a precipitant of both copolymer blocks. F
rom classic light scattering measurements as a function of temperature
different thermodynamic magnitudes have been obtained It has been obs
erved that at constant temperature, the critical micelle concentration
increases with the percentage of 2-chlorobutane. A opposite behaviour
has been obtained employing 2-pentanol. Using classic and dynamic lig
ht scattering and viscometry the micellar structure has been character
ized. Micellar size remains constant whereas the association number va
ries, decreasing as the 2-chlorobutane increases and increasing as 2-p
entanol porcentaje increases in the binary mixture.