On the Effect of High Energy Radiation to Polymers I. Cross-linking and Degradation

Molecular and macromolecular structure changes in polyamide 11 during thermal oxidation

“…This comes from the fact that the chromatogram exhibits gently a tail in low molar weight region with no real return to baseline before the elution end column peak corresponding to eluent impurities. The number of chain scission (s) and crosslinking (x) events per mass unit can be assessed according to Saito relationship assuming random chain scission and crosslinking processes [25]:…”

Molecular weight distributions of irradiated siloxane-based elastomers: A complementary study by statistical modeling and multiple quantum nuclear magnetic resonance

“…Note that Eqn. (4) is identical with the mathematical formula governing chain-scissioning in free polymer chains derived by Saito [17].…”

“…A number of studies on the degradation of siloxane polymers by irradiation concentrate on the calculation of the relative ratios of cross-linking to chain-scissioning, either via the use of Charlesby-Pinner analyses of the sol-fraction [16] or via a statistical approach first outlined by Saito [17]. The most satisfying practice is probably the analysis of molecular weight distributions obtained by gel permeation chromatography (GPC) from irradiated soluble polymer chains [17][18][19].…”

“…The most satisfying practice is probably the analysis of molecular weight distributions obtained by gel permeation chromatography (GPC) from irradiated soluble polymer chains [17][18][19]. For cross-linked networks, however, the use of GPC to obtain insight into the effects of radiation on the distributions of the chain lengths in the polymer network is not feasible since network chains are insoluble.…”

New Developments in the Field of Radiochemical Ageing of Aromatic Polymers

“…The Charlesby-Pinner's (Charlesby, 1960) from an analysis of the residual soluble fraction after beginning of sol-gel transition, -Saito's equations (Saito, 1958) describing the average molar mass changes for soluble polymers before the sol-gel transition. The corresponding mathematical treatment of these theories differs for Y-and Hcrosslinking: 1.…”