1. Schematically demonstrate the structural difference between polyethylene (PE) and polypropylene (PP). PP has been used in the finger joint (Figure 9.4b). What mechanical property of PP makes it the biomaterial of choice for this application? Explain why PP has a better flexural fatigue resistance than PE. 1 Arthritic hand Implants (a (b) Figure 9. Application of propene mine chemistration Courtesy y Randolo schrest Wall Multimedia Group Mar 2002 Papinh thymston) Awam