Irradiation molar mass distribution

The GPC technique was used to determine gel formation. Figure 13 shows the soluble fraction of aromatic polysulfone I measured with this technique after irradiation at 30 and 150°C. The relative radiation resistance of different polymers can be obtained by comparison of the gel doses (the highest dose for complete solubility of the polymer) provided that the initial molar masses of the of the polymers are known, or from G(S) and G (X) values these can be derived from the dose dependence of the soluble fractions beyond the gel dose, using a Charlesby-Pinner, or Saito-type plot with allowance for the molar mass distribution. 

Molar mass distributions can be derived by means of probability calculations or, in detail, by considering the primary reactions. This last method is demonstrated for a polymerization in which the monomer may be activated by light quanta (M M ) and termination occurs only through disproportionation. The formation of the activated monomer = Pf then depends on the intensity of the irradiating light 7/, and the reactions through which the activated monomer is lost ... 

The distribution of volatile products of low molar mass from the irradiation of poly (olefin) s is strongly dependent on the nature of substituents (short-chain branches) on the backbone chain. Hydrogen is the main volatile product with smaller quantities of alkanes and alkenes. 

---