Calculation of stress-strain relationship of chlorinated polyethylene rubber/nitrile rubber blend by regulating cross-linking density of chlorinated polyethylene rubber phase

Chlorinated polyethylene rubber (CM)/nitrile rubber (NBR) blend vulcanizates were prepared by mechanical blending method with CM and NBR as main raw materials, the cross-linking density of CM phase in CM/NBR blend vulcanizate and the stress-strain relationship of CM/NBR blend vulcaizate were characterized by regulating the dose of vulcanization system of CM phase in CM/NBR blend combined with the means of equilibrium swelling method, testing mechanical properties and theoretical calculation, and the influence of the change of cross-linking density of CM phase on matching degree of the modulus of two phase in CM/NBR blend vulcanizate and mechanical properties of CM/NBR blend vulcanizate were studied. The results showed that the change of the modulus of CM/NBR blend vulcanizate caused by the increase in cross-linking density of CM phase was greater than that of its own; with the increase of modulus, the influence of the change of cross-linking density of CM phase on the modulus of CM/NBR blend vulcanizate increased; by comparing the stress-strain relationship of CM phase and NBR phase in CM/NBR blend vulcanizate and the change of mechanical properties of CM/NBR blend vulcanizate, it was proved that the decrease of the cross-linking density of CM phase was a process of the gradual matching of the modulus of the two phase; compared with the error of the measured stress-strain relation, that of the stress-strain relationship predicted by fitting model was relatively smaller, which indicated that fitting model had certain applicability.