The expression of the rule of mixtures for the tensile strength of binary polymer blends was modified.The two factors which reflect the interfacial behavior between the two phases and the structural affection respectively

F and M

were maintained in the modified expression.The modified expression was applied to the systems of NR/EPDM

LDPE/PS

PVC/PMMA and PVC/PS blends. F and M according to the model were calculated by the method mentioned in the paper. The obtained F values were in accordance with the solubility parameters of these polymers.The calculated values according to the modiied expression also indicate that co-curing increases structural affection and compatibilizer mainly progresses interfacial situation.The results showed that modified expression and structural affection of polymer binary blends.