Improved toughness of poly(ether-block-amide) via melting blending with thermoplastic polyurethane for biomedical applications

Biocompatible polyether-block-amide (PEBA) copolymers have been widely applied in invasive medical devices. Due to the high hard segment ratios and poor toughness, PEBAs generally suffer from low fracture extensibility, large brittleness, and low compliance. Modification of PEBA with thermoplastic polyurethane (TPU) elastomer via melting blending is thus needed to improve the toughness. Mechanical experiments exhibited that when the content of TPU was 3% (w/w), the elongation at break and the notched impact strength of PEBA/TPU composite were improved by 12.4 and 30.5%, respectively. Field emission scanning electron microscopy results illustrated that there existed two toughening mechanisms in PEBA/TPU composites, including the crazing with a shear-yield mechanism and the single-layer crack extension mechanism. Moreover, Fourier transform infrared spectroscopy revealed that the intermolecular interaction between PEBA and TPU was enhanced due to hydrogen bonding, leading to the tensile mechanical properties and toughness increased. (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47397.