SOLUTION PROPERTIES OF BLOCK COPOLYMERS OF POLY(ISOPRENE - STYRENE) .I. MOLECULAR DIMENSIONS BY VISCOSITY AND LIGHT SCATTERING METHODS

Viscosity and light scattering data for block copolymers of poly(isoprene : styrene) have been determined in the solvents toluene, cyclohexane and methyl isobutyl ketone. The displacement length parameter 〈 P2 〉 +/Z+ reaches a maximum in the middle of the composition scale. Binary cluster integrals calculated from second virial coefficients show that the magnitude of the volume effect increases over the range of solvents MBK to toluene. An attempt to explain these effects in terms of increased interaction is made here but such an interpretation must be treated with considerable caution. © 1969.