γ‐irradiation of styrene copolymers

Copolymers of styrene‐methyl methacrylate were irradiated in vacuo with γ‐rays; viscosity changes and gas yields (moles gas per mole methyl methacrylate in copolymer) for H2, CO, CO2, CH4, HCOOCH3, and CH3OH were examined at doses of 1.0 Mrep to 10.0 Mrep. It was found that styrene molecules protect the copolymer from degrading while decreasing the gas yields up to a styrene concentration of about 0.5 mole fraction; above this concentration, these radiation effects are independent of composition. When styrene–methyl acrylate copolymers were irradiated, styrene offered protection aganist gelation but simultaneously increased the gas yields (gases liberated were identical with those from the first system).