ABSTRACT

We have discussed the use of polyurethanes in environmental applications. Certainly the conditions under which a polyurethane must operate are by no means mild. Arguably, however, the most severe environment one can imagine in which a material must operate and above all cause no harm is inside the human body. Not only must the material function in above-ambient temperatures, but it is continuously held in a hydrolytic environment containing chemicals and proteins. Furthermore, the human body has developed defensive strategies that attack foreign bodies by attempting to degrade or encapsulate them. A polyurethane product designer who develops a device intended for implantation into the human body must consider additional stresses not normally encountered in more traditional applications.