Electron beam irradiation of polystyrene/poly(vinyl methyl ether) blends

The effects of electron beam radiation on the rheological behavior of a polystyrene/poly(vinyl methyl ether) blend as a function of absorbed dose, composition, and temperature, were investigated. The purpose of this research has been to modify the viscosity of polystyrene by studying the influences of the addition of a small amount of poly(vinyl methyl ether), combined with the exposure of the blends to low radiation doses. It is shown that the crosslinking behavior, in terms of the changes in the viscosity, is more pronounced and significant for the highest PVME content system composed of 10 wt % PVME. The other blends under consideration in this study do not display significant modifications in their rheological response after irradiation.

The effects of radiation and composition on the temperature dependence of the viscosity is illustrated using the Arrhenius Law. The results obtained, in terms of flow activation energy, Ea, show that no real changes occurred due to radiation. On the other hand, it is found that the flow activation energy is strongly dependent on the blend composition.

The phase separation temperature as a function of radiation dose and composition is also examined. It is shown that the most noticeable change occurs at a radiation dose of 10 Mrads, the phase separation temperature increasing also as PVME content increases in the blend composition.