The principal objective of this study was to explore the compatibility of a blend of
two synthetic elastomers viz., ethylene-propylene-diene rubber (EPDM) and
chlorobutyl rubber (CIIR). Various commercial grades of EPDM were blended
with a specific grade of CIIR at different proportions. The mechanical properties such
as tensile strength, tear strength, ageing resistance, etc. were studied. On the basis of
the observed physical properties, two particular grades of EPDM were found to be compatible
with CIIR. Differential scanning calorimetry and scanning electron microscopy
confirmed the results. Chlorosulphonated polyethylene was added as a compatibilizing
agent to overcome the phase separation of the other two incompatible grades of EPDM
in blending with CIIR. The results revealed that the addition of compatibilizer greatly
improves the compatibility and thereby the properties of the blends.