One of the important considerations in the selection of a polymer blend for
a practical application is how it resists crack growth and/or failure from
a material flaw, under static or fatigue conditions. The blending of two o
r more rubbers is a useful technique to improve certain properties not inhe
rent in a single rubber. In the present work, fatigue and mechanical failur
e tests have been performed to evaluate the behaviour of blend vulcanizates
of natural rubber/styrene butadiene rubber (NR/SBR) and natural rubber/but
adiene acrylonitrile rubber (NR/NBR). It has been found that the fatigue li
fe and the strain energy varies linearly with blend composition in the comp
atible blend (NR/SBR), but they deviate from linearity in the case of the i
ncompatible blend (NR/NBR). These results are in good agreement with the me
chanical property measurements for the various compatible and incompatible
blends studied.