Abstract
Solubility of potassium chloride (KC1) in poly(ethylene oxide) (PEO) oligomer showed a negative temperature dependence. The solubility of KC1 in PEO, with a molecular weight (Mw) of 200, was 0.7 mol// at 57 °C, but it was reduced to 0.2 mol/l at 148 °C. The cry stal of KC1 formed in the PEO oligomer was microscopically analyzed to be cubic crystal system which was the same as that recrystallized from an aqueous solution. The negative temperature dependence of the KC1 solubility was also observed in other PEO oligomers (M, =300and 400). The solubility of KC1 decreased with increasing molecular weight of the PEO. This is ascribable to a decrease in the relative content of the terminal hydroxyl groups.
