FT-IR spectroscopic studies of polyurethanes: IV. Studies of the effect of the presence of processing aids on the hemocompatibility of polyurethanes

Abstract

Many types of proprietary processing aids are used by the manufacturers of polymer medical devices, which are difficult to completely eliminate from the end product. In such cases, it is important to investigate how such processing aids affect the properties of the materials. One such material is Pellethane and a most commonly found processing aid is wax. We investigated the effect of the presence of such wax on hecompatibility properties, particularly on the adhesion and activation of human platelets, on a group of Pellethane samples with varying amounts of wax. The effectiveness of cleaning agents, like Freon, was examined for wax removal. The type and quantity of wax present within the near-surface regions of the Pellethane tubings was estimated by using the FT-IR-ATR technique. The presence of bis amide processing wax was found to affect the hemocompatibility properties of the Pellethane samples. Correlation between hemocompatibility and the amount of wax was made; platelet activation, as well as amount and density of fibrin formation, showed a linear correlation.