CO-vulcanization of ayrylonitrile-butadiene rubber and ethylene-propylene-diene rubber blends

In the present study, attempts have been made to covulcanize acrylonitrile-butadiene rubber (NBR) and ethylene-propylene diene (monomer) rubber (EPDM) blend in presence of a multifunctional rubber additive, namely, bis(diisopropyl) thiophosphoryl disulfide (DIPDIS). It is noticed that DIPDIS is very much effective in producing filled blend vulcanizates of techno-commercial importance, especially by two-stage vulcanization (TSV), which significantly improve the physical properties. The polarity difference between the constituting elastomers of the blend could be narrowed through the introduction of rubber bound intermediates in the non-polar EPDM. The modified EPDM is likely to restrict the curative and filler migration across the phase boundaries. As a result significant control over cure-rate mismatch is achieved. SEM study further indicates development of coherency and homogeneity in the blend systems.