Rubber blends opportunities for future research

In measurements of dynamic mechanical properties over a temperature range, the appearance of intermediate loss peaks and the concomitant decrease of the loss peaks of the individual polymers in a blend is a useful criterion of blend compatibility. Microscopy and x‐ray data are reviewed which demonstrate that phase heterogeneity prevails in rubber blends, Compatibilization of these blends, as judged by dynamic loss measurements, can be achieved through a vulcanization process, which promotes interaction between the heterogeneous phases, The matching of solubility parameters of the blend polymers is not a necessary condition, because compatibility, as defined above, can also be observed in blends of rubbers with significantly different solubility parameters, provided an appropriate vulcanization system is used to promote phase interaction.