Pellethane surface

Gu et al. [23] used ozone to pretreat a Pellethane surface and later functionalized the surface with polyacrylic acid. The surface hydrophilicity of Pellethane thermoplastic polyurethane ( TPU ) is significantly improved by showing a much lower water contact angle (CA 25° vs 92° of pure Pellethane TPU, for CA test, please see Section 2.2) The COF of the modified surface was as low as 0.1. 

Park et al. [44] modified a Pellethane surface with poly(ethylene glycol) (MW) = 1000, PEGlk carrying terminal hydroxyl, amino, and sulfonate groups, respectively, to reduce bacterial adhesion (Fignre 2.8). After modification, the authors measured the dynamic C A before and after hydration using the Wilhelmy plate method. 

Table 2.1 Dynamic contact angles of PEG-modified Pellethane surfaces...

All polyurethane materials used in this study were either in the form of extruded tubes (Tygothane, Superthane, Pellethane) or as films cast on clean glass from reagent grade dimethylacetamide (DMAC). Only the luminal surfaces of the tubes and the glassfacing sides of the cast films were observed by ESCA. 

Polyurethane (PU) bead, sheet (Pellethane 2363-80A, thickness 1 mm Dow Chemical Co.), and tubing (Royalthene R-380 PNAT, ID 1.5 mm, OD 2.0 mm Uniroyal Chemical Co.) were used in this experiment. Figure 1 illustrates the modification scheme of PU surfaces. The preparation methods of various sulfonated PUs have been described in detail elsewhere.(8)... 

Polyurethanes, due in part to their flexibility and toughness, are perhaps the polymer of choice for ventricular assist devices and blood pumps. Consequently, they have received considerable interest as bloodcontacting materials. In nonhuman primates, those polyurethanes, such as Pellethane , which exhibit the most hydrophobic surface chemistry produce the least platelet consumption [12]. In dogs, early platelet interactions with polyurethanes vary considerably although relationships to polymer surface chemistry remain unclear [13]. Thus while polyurethanes are chemically versatile and possess many desirable mechanical properties, it is generally not possible to predict their biologic responses in humans. 

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