Thermal degradation of aliphatic polysulphide-based elastomers☆

Thermal degradation in vacuo of a series of linear and crosslinked homo- and copolymeric polysulphide-based elastomers prepared from bis-(2-chloroethyl) formal was studied between 125 and 260°C. The resulting degradation products were identified and determined quantitatively. Scission of the S-S bonds resulting in the formation of cyclic sulphur-containing compounds represents the first stage of degradation. The proposed mechanism of thermal degradation was confirmed by NMR, EPR and IR spectroscopic data and by mass spectra. The thermal stability has been correlated with the chemical structure of the repeating unit.