Pellethane poly

Despite the improvements, a more durable elastomer was clearly needed. A battery of polyurethane elastomers including Pellethane were prepared and implanted subcutaneously in rats. Before implantation, the polymers were extruded into tubes and elongated over mandrels to 400%. The implants were left in place for 6 months and examined under a scanning electron microscope. One of the better performing polyurethanes was based on poly(l,6-hexyl 1,2-ethyl carbonate) diol. Polyesters typically are considered less durable due to the presence of esterase enzymes in vivo. From the data recovered during the implant period, it was determined... 

Pellethane 2103-80A (Upjohn) poly(co-polytetramethylene ether glycol-diphenylmethane diisocyanate). Polyurethane 2000E poly(co-propyleneglycol-4,4 -diphenylmethanediisocyanate-ethylenediamine). 

Pellethane CPR 2102 polyurethane, obtained from the Upjohn Company, was the other polyurethane studied. (Hereafter this material Is referred to as polymer "B .) For polymer B the molar ratio of polyester to MDI Is 2.95, and the ester Is poly(capro-lactone). This material Is reported to have Initial properties similar to polymer A when both materials are post cured at llO C for 16 hours. The polymer B samples were previously post cured. 

Such poly(ether urethane urea)s are well known as Lycra and Spandex in the textile industry and as Biomer and Pellethane in the biomedical field. 

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. 

In fact, thermoplastic polyurethanes (TPU), a subcategory of TPEs, were among the first to be made commercially available. In the United States, TPUs were marketed for the first time in the 1960s by Goodrich, Mobay, and Upjohn under the trade names Estane , Texin , and Pellethane , respectively. In 1972, DuPont commercialized thermoplastic poly(ether ester)s derived from... 

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