There were investigated physical and physico-mechanical properties of elastomers based on three series of epoxy-terminated oligomers based on differently structured diisocyanates and diamines. The use of 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate enabled better strength properties to be obtained owing to the implementation of the strengthening effect. Also, there was elicited a positive influence of an increase in the content of 3-aminomethyl-3,5,5-trimethylcyclohexylamine in a mixture of hardeners on the strength of elastomers; it was associated with enhancing polarity of a polymer chain, therewith giving rise to changes in the phase separation degree.