Rheological and densitometric studies of poly(propylene oxide)-water mixtures over a range of temperatures

Rheological and densitometric data are reported for aqueous solutions of poly(propylene oxide), molar mass 400 (PPO 400), over the concentration range 0-1 weight fraction and a temperature range 4.8-55 degrees C. Negative excess partial specific volumes were found, which varied as a function of temperature and concentration of PPO and which were found to correlate with the viscoelastic behaviour of the solutions. The PPO molecule, in the pure phase, was found to undergo a change of conformation at 30 degrees C.