Unperturbed dimensions of poly(ethylene oxide)

Abstract

Abstract The intrinsic viscosities of fractions of poly(ethylene oxide) in the molecular weight range 1.5 × 10 3 to 10 6 have been measured at 25°C in benzene, carbon tetrachloride, and acetone; at 35°C in 0.45 M aqueous potassium sulfate; and at 50°C in methyl isobutyl ketone and diethylene glycol diethyl ether. The latter three are practically theta solvents. The value of ( r 0 2 / M ) 1/2 for poly(ethylene oxide) is calculated to be 0.84 Å from the molecular weights of the high molecular weight fractions, and their intrinsic viscosities in the theta solvents and acetone. Erroneous values result if the usual methods of determination are applied to the data obtained for the low molecular weight (<10 4 ) fractions or to the intrinsic viscosities in the very good solvents, benzene and carbon tetrachloride.