Formic acid crosslinked epoxidized natural rubber (FC-ENR) with precrosslinking epoxide level of 33 mol% was
prepared and compounded without any further curative and in blends with unmodi®ed natural rubber. A total of
four dierent materialsÐFC-ENR, NR, FC-ENR/NR blend (25/75) and FC-ENR/NR blend (50/50)Ðwere
prepared for analysis and designated mixes K, L, M and N, respectively. All the materials were ISAF black ®lled at
30 pphr loading. With the exception of the unblended FC-ENR the rest of the materials were cured using the semi-
EV system. The unmodi®ed NR vulcanizate served as control. In the present communication we report the results
of our studies in the physical properties of the aforementioned vulcanizates. FC-ENR was found to have potential
as an eective modi®er for natural rubber.