Recent chemorheological studies on rubber vulcanizates

Abstract The structural changes of materials caused by chemical reactions are reflected in the viscoelastic behavior of these substances. Such viscoelastic behavior induced by chemical reaction was termed “chemorheology” by Tobolsky. This phenomenon is not readily observed in linear polymers since molecular flow, because of diffusion or chemical reaction, is generally much more rapid than relaxation. It has become possible, however, to establish chemorheology of linear polymers, by taking physical flow into consideration. As there is no mechanism for flow in crosslinked polymers, the rheological behavior at sufficiently high temperatures is almost always determined by chemical reactions. A significant problem in the degradation of crosslinked polymers is the determination of whether the scission of the crosslinked polymer occurs along the main chains or at crosslink sites. Both extreme cases have been studied theoretically and experimentally by A. V. Tobolsky and coworkers, while the case in which both ty...