Tuning Tpu Properties By Changing the Hard Segment Content

Among the most versatile polymers with applications spanning from high-tech biomedical to common daily use are the polyurethane thermoplastic elastomers. The phase segregated morphology of thermoplastic polyurethanes (TPUs) composed of hard and soft segments enables tailoring of processability and properties in such systems. Hard segments can act as physical crosslinks in the soft segment matrix of thermoplastic polyurethanes leading to their elastomeric properties.

In this study, TPU’s were synthesized using polycaprolactonediol as soft segment and 1,4- phenylene diisocyanate (PPDI) extended with 1,4-butanidiol as hard segments. By keeping constant the overall isocyanate to alcohol groups molar ratio (r=[NCO]/[OH]) while changing the polyol and chain extender composition, TPU’s with different hard segment content were obtained The effect of composition on the mechanical and thermal properties of TPUs were analyzed. The presentation will emphasize the importance of composition within the framework of a constant molar ratio “r” on processability and final properties of TPUs obtained in a two-step polymerization process.

Keywords: Thermoplastic Elastomer Polyurethane, hard segment content, isocyanate to alcohol molar ratio