Effects of radiation on styrene and α‐methyl styrene in different organic solvents and in the pure state. A study by pulse radiolysis

Styrene and α‐methyl styrene, both in solution in organic solvents and in the pure state, have been subjected to 2 μ sec pulses of 4 MeV electrons. The absorption spectra of the transient intermediates formed have been measured and kinetic studies have been carried out. The results for styrene were similar to those for α‐methyl styrene. In the case of solutions of styrene in cyclohexane, transients absorbing at 320 mμ and 390 mμ were seen. The absorption at 320 mn is attributed in part to a slowly disappearing polymer radical with a structure resembling benzyl. The absorption at 390 mn disappears rapidly and is attributed to a radical anion. Various additives interfere with its formation. The effect of styrene concentration and dose rate on the formation of the transients is reported. Styrene reacts rapidly with solvated electrons in methanol, but the anion formed becomes proton‐ated rapidly. In benzene the absorption appears at a wavelength similar to that seen with pure benzene. Intense absorptions at 290 mμ and 320 mμ are seen in carbon tetrachloride solution. Absorptions at ∼320 mμ and ∼400 mμ are seen when pure styrene or α‐methyl styrene are pulsed. A stable species absorbing at 320 mμ is also present. Values for rate constants are compared with those obtained from measurements of polymer formation.