Abstract: Four kinds of polyurethane (PU) elastomers were synthesized from polytetrahydrofuran polyols (PTMG), polycaprolactone polyol (PCL), and 4, 4′- diphenylmethane diisocyanate with 1,4 - butanediol as a chain extender and trihydroxy polyether polyols as a crosslinker. The effects of the alteration of the PTMG and PCL molecular weight on the mechanical, thermal, and rheological properties of the PU elastomers were studied by means of unversal testing machine, dynamic mechanical thermal analysis (DMTA), differential scanning calorimetry (DSC), and ARES rheometer. It was revealed that PCL-based PU elastomers had higher tensile strength, hardness, plateau modulus, soft segment glass transition temperature, and the apparent viscosity of reaction system than PTMG-based PU elastomers, while PTMG- based PU elastomers showed higher hysteresis loss. It was also found that the above properties denpent on the molecular weight of polyols in PU elastomers synthesized from the same kind of polyols.

Key words: polyol, polyurethane elastomer, mechanical property, thermal properties, rheological behavior