Structural characterization of vulcanizates part X. Thiol‐disulfide interchange for cleaving disulfide crosslinks in natural rubber vulcanizates

The thiol‐disulfide exchange reaction is shown to be applicable to cleavage of disulfide crosslinks in accelerated sulfur vulcanizates of natural rubber. The reaction, in conjunction with the previously reported selective cleavage of polysulfide crosslinks, is used to determine the distribution of crosslink types for several accelerated sulfur vulcanization systems as a function of cure time. Discrepancies between the results and published results obtained using the reagent sodium di‐n‐butyl phosphite for disulfide crosslink cleavage are discussed.