Electrospinning of biostable polyisobutylene-based thermoplastic polyurethanes

摘要

Electrospinning of a previously synthesized biostable polyisobutylene (PIB)-based thermoplastic polyurethanes (TPU) have been performed as materials with potential applications as vascular grafts. Electrospun mats were generated with fiber diameters in the submicron to 2 μm range as observed using scanning electron microscopy. Porosity of electrospun TPU fiber mats was investigated using Hg intrusion porosimetry. Fiber mats were found to have a distribution of pore sizes between 100 nm and 100 μm, with overall porosity between 50 and 70%. Thermal analysis of electrospun mats showed orientation of the TPU chains compared to the bulk as-synthesized material. Tensile failure properties were characterized, showing ultimate tensile strength of 1.6-6.5 MPa and ultimate elongation of ～300-100% with TPUs of increasing hardness from Shore 60A to 100A. Strain-recovery experiments showed good recovery of tensile strain at significant stresses. The previously demonstrated biostability of these PIB-based TPUs, together with the excellent reported mechanical properties, indicates great promise for these materials as biostable vascular grafts.