Polyurea-urethanes are one of the polyurethane categories that causes better phase separation due to increasing the hard segment length and non-covalent interactions. In this research, hydroxyl-terminated polybutadiene based polyurea-urethanes have been synthesized via one-pot polymerization of triethanol amine triflouroborate comlex as cross-linker, isophoron diisocyanate as curing agent and variable values of 4,4`- bis (phenyl amine) methane as chain-extender and their mechanical and thermal properties have been investigated and compared to same polyurethane sample with no chain-extender. Samples chemical structure characterized by FT-IR and their mechanical and thermal properties investigated by Tensile and Dynamical- Mechanical Analysis. The results revealed that chain-extender insertion in polyurea-urethanes structure led to decreasing in samples mechanical properties. In addition, samples exhibit more viscous behavior in room temperature. Moreover, chain-extender content increasing caused higher mechanical properties due to intensifying non-covalent interaction between polymer hard segments.