The elevated temperature radiation chemistry of some engineering thermoplastics containing aromatic groups

The electron beam radiolysis of poly(oxy-1,4-phenylenesulfonyl-1,4-phenylene-oxy-1, 4-phenyleneisopropylidene-1,4-phenylene), poly(oxy-1,4-phenylenesulfonyl-1,4-phenylene) and poly(oxy-carboxy-1,4-phenylene-carboxy-oxy-1, 4-phenyleneisopropylidene-1,4-phenylene) have been investigated at doses in the range 0-300 kGy and at temperatures from room temperature up to the Tg of the polymers. The study has revealed results similar to those previously reported for gamma radiolysis of the polymers at low doses at room temperature, which showed that the tensile properties of the polymers were enhanced on radiolysis, but that the effect becomes less as the temperature of radiolysis increases. The observed results were consistent with simultaneous scission and cross linking of the polymer chains, together with realignment of the scissioned polymer chain ends, which has the effect of enhancing polymer chain interaction and hence polymer rigidity. (author)