Investigation of 4,4'-Bis(Phenyl Amine) Methane Chain-Extender Effect on the Mechanical and Thermal Properties of HTPB Based Polyurea-Urethane Network

Polyurethane- ureas are one of the polyurethane categories that exhibit better phase separation due to increasing the hard segment length and higher strength due to presence of three-dimension non-covalent interactions specially hydrogen boding. In this research, hydroxyl-terminated polybutadiene based polyurethane-ureas network 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. The results revealed that chain-extender insertion in polyurethane-ureas structure led to decreasing in samples mechanical propertie in contrast to previous reported results. In addition, samples exhibit more viscous behavior in room temperature, too. Moreover, chainextender content increasing caused higher mechanical properties due to intensifying non-covalent interaction between polymer hard segments. Samples chemical structure characterized by FT-IR and their mechanical and thermal properties investigated by Tensile and Dynamical- Mechanical Analysis respectively.