Characterization of Tensile Strength Property of Polyurethane –Based Composite Used for Coronary Artery Substitution

Polyurethane elastomers possess a combination of properties that make them particularly well-suited for long-term use in implanted biomedical devices. This work focuses on developing a biomaterial with tensile strength proximally to natural arterial tissue by preparing a polymer blend base elastomer of polyurethane (PU) combined with silicone rubber (SR), taking into consideration the inertness and biocompatibility of both PU and SR. The polymer blending group ratios of (PU/SR) were (98:2), (96:4), (94:6), (92:8), and (90:10) respectively. The prepared blends were used to prepare composite materials by adding additives of (0.2%) titanium dioxide (TiO2), and (0.5%) of calcium fluoride (CaF2) to the mother polymer blend (PU/SR) to improve their tensile strength. The tensile test results show that all prepared polymer blends (1B, 2B, 3B, 4B, 5B) have lower tensile strength when PU blended with SR compared to the control reference sample of polyurethane. Adding Titanium dioxide (TiO2) revealed a higher tensile strength of specimen 3T (94 PU- 6 SR- 0.2 TiO2) compared to the mother blends and control. Also, adding Calcium fluoride (CaF2) shows higher tensile strength of specimen 3C (94 PU- 6 SR- 0.5 CaF2) compared to mother blends and control. The hemolytic index (HI) of the prepared composites was also studied, and the results demonstrated a significant improvement in HI in blends, particularly in mother blends (2B, 3B, 4B, and 5B) and mother blends containing TiO2(3T, 4T, and 5T) compared to the PU control reference.