Ethylene tetrafluoroethylene molecular structure

Isomerism is a term covering different molecular conformation effects. We will not speak here again on the type of information that can be gained on the alternating or block structure of copolymers, as was explained above for an ethylene-tetrafluoroethylene copolymer. For homopolymers, we will distinguish various categories ... 

Polymers are widely used as implant materials because they have physical properties that are similar to those of natural tissues. Examples are long-term and shortterm implants such as blood vessels, heart valves, membranes, mesh prostheses, corneas, tracheal prostheses, dental materials, parts of the nose and ear, knee and hip joints, and others. The synthetic polymers used include polyethylene (PE), particularly ultrahigh molecular weight PE (UHMWPE), poly(ethylene terephthal-ate) (PET), poly(tetrafluoroethylene) (PTFE), polyurethane (PU), and poly(methyl methacrylate) (PMMA). The necessary sterilization before implantation can be performed by y-irradiation, heat (steam), or chemical treatment (ethylene oxide), which should not cause any structural degradation of the polymers. Current challenges in research include the development of biomimetic materials that match both the mechanical and biological properties of their natural counterparts. 

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