Synthesis of HMDI-based segmented polyurethanes and their use in the manufacture of elastomeric composites for cardiovascular applications

For short-term cardiovascular application, segmented polyurethanes (SPUs) based on 4,4-methylenebis(cyclohexyl isocyanate) (HMDI), polytetramethylenglycol (PTMG) and 1,4-butanediol (BD) were synthesized and characterized by spectroscopy (FT-IR, 1H-NMR) and thermal (TGA, DMA, DSC) and mechanical techniques. The segmented nature of the SPUs was not easily established by spectroscopic means; however, TGA allowed the quantification of the rigid segments content by the significant mass loss between 348 and 356°C. The alpha transition was detected by DMA and related to the T g of the soft segments at –50°C, while DSC showed the presence of an endothermic transition above 80°C attributed to the melting of rigid segments. Two types of composites were prepared using the synthesized SPUs and Lycra® (either T162B or T162C). The first one consisted of a two layers casting laminated while the second one was a classic unidirectional fibre-reinforced material. Laminate composites prepared with SPU containing 23.9% and 3...