Radiation Modification of Poly(ethylene oxide)

The electron or gamma irradiation of high molecular weight poly(ethylene oxide) (Polyox) causes marked changes in solution properties, molecular-weight distribution, and molecular weight. Crosslinking and degradation both occur, but their relative importance is determined by experimental conditions such as dose rate, oxygen concentration, and particle size. At low dose rates and in the presence of air, the G (scission) value is about 200. Changes in molecular weight and molecular-weight distribution have been measured and related to the gross improvements observed in solution properties: lower viscosity, increased shear stability, and longer shelf life.