Segmented polyurethane elastomers made from linear polybutadiene diols terminated with primary (Krasol LBH-P) or secondary (Krasol LBH) hydroxy groups, alicyclic diisocyanate, and aliphatic chain extender were prepared and tested. The system was chemically crosslinked either through isocyanurate, that is, hexahydro-1,3,5-triazine-2,4,6-trione groups (formed by catalyzed cyclotrimerization of isocyanate groups), or by low molecular weight triols. The best balance of stress-strain properties and reasonable thermal stability was obtained for systems in which only a small amount of chemical crosslinks was present in predominantly physically crosslinked networks, The influence of the type of polymer diol, chemical crosslinking, diisocyanate, and technique of preparation on mechanical. thermal, and swelling properties is discussed.