TURBIDITY MEASUREMENTS OF BINARY POLYSTYRENE SOLUTIONS NEAR CRITICAL SOLUTION POINTS

Correlation lengths (xi) and susceptibilities (chi) for three binary mixtures of methylcyclohexane + polystyrene (M(W) = 13 000, 23 000, and 29 000) at various temperatures near the upper critical solution points have been determined by a series of turbidity measurements at various wavelengths and temperatures. The critical exponents-nu and gamma have been determined from the temperature dependences of xi and chi and are in a resonably good agreement with the theoretical predictions. The prefactors xi-0 and chi-0, which have been determined by two methods, are uncertain by more than 20%, but their ratio has been determined more precisely.