EVALUATION OF MAIN-CHAIN CROSSLINKING AND SCISSION IN AROMATIC POLYSULFONES.

The rates of crosslinking and scission during degradation of polymers can be determined from the decrease in the fraction of soluble polymer beyond the gel point, where some of the polymer forms a macro network. The authors have developed an experimental technique for measuring the soluble fraction of irradiated polymers using gel permeation chromatography (GPC), which requires only small amounts of polymer (ca 50 mg), is simple and rapid, and gives excellent reproducibility. This technique has been applied to a variety of aromatic polysulfones with different x units and to copolymers with varying proportions of two different x units from I, II, III and IV. The objective has been to evaluate the variation in radiation resistance with molecular structure