Surface copolyether-urethane-ureas

The Effect of Polyether Segment Molecular Weight on the Bulk and Surface Morphologies of Copolyether-Urethane—Ureas... 

In summary, the surface chemical and morphological structures of block copolyether-urethane-ureas may be determined by ESCA and FTIR coupled with internal reflectance techniques to probe the surface and bulk structures. These ESCA and FTIR data are being used to model the domain-interface structure of these copolyurethanes and their interaction with blood protein. 

Since the current prosthesis materials (Dacron and Teflon) are thrombogenic, our approach to solving the small diameter vascular prosthesis problem was to develop a blood compatible polymer. Much of these studies have been summarized in Reference 1. One of the polymers that we prepared which appeared to have a nonthrombogenic surface was a block copolyether-urethane-urea material. However, when this urethane material was fabricated into small diameter solid wall tubes and implanted in dogs, occlusion occurred within several days. Prostheses recovered from these experiments gave evidence that the thrombus was originating at the anastomosis between the artery and the prosthesis. We believed that a mismatch in compliance between the polymer and... 

Multiple block copolymers form a domain-matrix morphology due to the chemical and steric incompatibilities of the two chemically different blocks. The surface molecular and morphological structures of a series of block copolyether-urethane-ureas have been studied in detail via Electron Spectroscopy for Chemical Analysis (ESCA) and Fourier Transform Infrared Spectroscopy (FTIR) coupled with internal reflectance techniques. ESCA provides elemental information concerning the very surface, while FTIR provides the molecular and secondary bonding Information of the surface and into the bulk. Bulk and surface chemical and morphological structures are shown to be quite different, and are affected by synthetic and fabrication variables. 

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