Microporous segmented polyetherurethane vascular graft: I. Dependency of graft morphology and mechanical properties on compositions and fabrication conditions

The influence of polyurethane compositions and fabrication conditions on th e pore morphology and mechanical properties of microporous segmented polyet herurethane (SPEU) grafts, which were produced by the coagulation technique , were carefully investigated in this article. SPEU resins based on polytet ramethylene oxide (PTMO) were synthesized by the solution polymerization me thod. Different types of coagulant were adapted to examine the feasibility of producing a microporous SPEU graft with good structural regularity. The experimental results indicate that a microporous SPEU graft with a uniform pore structure can be fabricated quite conveniently by using a proper conce ntration of water and ethanol mixed coagulant, Tensile tests demonstrated t hat the fabricated microporous SPEU grafts possess high mechanical strength s and satisfy the requirements as vessel replacements. The burst strength t est also revealed that the SPEU graft can sustain extremely high internal p ressure. Furthermore, a high compliant SPEU (high porosity) graft can be ob tained by blending a proper amount of "soluble filler" (i.e., free PTMO pol yol in this study) into the SPEU resin, (C) 1999 John Wiley & Sons, Inc.