THERMOPLASTIC SILOXANE-URETHANE COPOLYMER DEVELOPMENT

THIS PROJECT WILL TEST THE HYPOTHESIS THAT BIOSTABILITY OF THERMOPLASTIC POLYURETHANES (TPU) CAN BE IMPROVED BY REPLACING ALL OR PART OF THE POLYETHER SOFT SEGMENT WITH TELECHELIC POLYDIMETHYLSILOXANE (PSX) OLIGOMER DURING SYNTHESIS. THIS APPROACH IS BASED ON THE REPORTED IMPROVEMENT IN IN VIVO STABILITY OF SOLVENT-CAST POLYURETHANES THROUGH THE ADMIXTURE OF GRAFTING OF REACTIVE PSC INTO/ONTO URETHANE-BASED POLYMERS, AND THE KNOWN IN VIVOSTABILITY OF PSX. IN PHASE I, THE SUBCUTANEOUS IN VIVO STABILITY OF SEVERAL DIFFERENT POLYURETHANES WILL BE DETERMINED. AROMATIC TPUS FROM PSX, POLYTETRAMETHYLENEOXIDE AND POLYETHELENEOXIDE, ANDSEVERAL PSX/POLYETHER TERPOLYMER POLYURETHANE FILMS WILL BE CHARACTERIZED AFTER EXPLANATION BY BULK AND SURFACE ANALYTICAL METHODS CAPABLE OF DETECTING MOLECULAR WEIGHT REDUCTION AND CHANGES IN SURFACE CHEMISTRY AND MORPHOLOGY ASSOCIATED WITH THE DEGRADATION PROCESS. POSITIVE PHASE I RESULTS WILL BE UTILIZED IN PHASE II TO COMPLETE THE DEVELOPMENT AND COMMERCIALIZATION OF A FAMILY OF BIOMEDICAL PSX-TPUS. THESE MATERIALS WILL BE SUITABLE FOR SOLVENT CASTING, EXTRUSION, AND INJECTION MODELING. THEY WILL COMBINE THE BIODEGRADATION RESISTANCE AND DESIRABLE SURFACE PROPERTIES OF PSX WITH THE PROCESSING EASEAND WIDE RANGE OF BULK PROPERTIES AVAILABLE IN CONVENTIONAL TPUS.