NOTE OF THE ESTIMATION OF THE THETA-TEMPERATURE AND PSI-PARAMETER FROM THE CRITICAL-TEMPERATURE DATA

Critical values of the polymer volume fraction phi2,c and the interact ion parameter chi(c) have been computed for the case that the equation for the chemical potential of solvent contains terms nu(c)phi2(3) and zeta(c)phi2(4) in addition to chiphi2(2). For 0 less-than-or-equal-to nu(c) less-than-or-equal-to 1/3, the limits for infinite chain length are phi2,c(infinity) = 0 and chi(infinity) = 0.5. Quite different res ults axe obtained for nu(c) > 1/3, phi2,c(infinity) being finite and c hi(c)infinity lower than 1/2. Conclusions for the estimation of the TH ETA temperature and the entropy-of-dilution psi parameter are discusse d.