Energy transfer and radiolytic product formation in the system polystyrene–pyrene

In γ‐radiolysis of polystyrene at room temperature, the formation of radicals detected by ESR spectroscopy is greatly reduced in the presence of pyrene, while crosslinking and hydrogen production are almost unchanged. The formation of these radicals was shown to start from the first excited singlet state of polystyrene competing with radiationless energy transfer to pyrene. Crosslinking and hydrogen production, on the other hand, are independent of the formation of these radicals and attributable to hot hydrogen or ion‐molecule reactions. Besides energy transfer from polystyrene to pyrene by dipole–dipole interaction the results indicate that intramolecular energy transfer within polystyrene is present.