γ Radiolysis of Poly(butene-1 sulfone) and Poly(hexane-1 sulfone)

Abstract

It has been shown that poly(butene-1 sulfone) and poly(hexene-1 sulfone), which are 1:1 alternating copolymers of the type +CH2CHR-SO2+n, undergo rapid degradation upon irradiation in the solid state in air and in vacuo. G(fracture) = 10.7 for poly(butene-1 sulfone) at 0° and 9.8 for poly(hexene-1 sulfone) at 30°, both in vacuo. The values of G(fracture) were higher for irradiation in air. The main volatile product at 0° was sulfur dioxide, in comparable yield to G(fracture), suggesting specificity of C-S fracture and stabilization of main-chain fracture by SO2 elimination. Increasing irradiation temperatures resulted in increasing depropagation to the two comonomers as a result of the thermodynamic instability of the polymer. Hydrogen was the other main volatile product, and there were very small amounts of saturated hydrocarbons. The broad initial molecular weight distributions were only slightly reduced toward the most probable distribution, indicating that some cross-linking occurred.