This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: dy dv A F / / = Î· 2 2 3 bd FL fs = Ïƒ 3 3 R FL fs Ï€ Ïƒ = a Y K Ic Ï€ Ïƒ = x P P J M âˆ† âˆ† = (cm 3 STP)(cm)/(cm 2-s-Pa) HA-Ca 10 (PO 4 ) 6 (OH) 2 UHMWPE â€“ semicrystalline thermoplastic. High molecular weight makes it very tough because of inter-chain tangling. Considerable level of crystallinity â€“ quite hard. PP â€“ linearly oriented helical crystal structure, when stretch melted forms an axial tensile strength. Quite flexible. Silicone rubber â€“ quite flexible because of Si-O backbone and lack of crystallinity. Cross-links make it elastomeric PUU quite rubbery, due to mechanical crosslinks caused by phase separation into hydrophobic hard secments and hydrophilic soft segments. Soft segments tend to occupy the surface in aqueous env.(e.g. blood) which aid in resisting the adsorption of blood plasma proteins and the adhesion of platelets. All PUs share high abrasion resistance, toughness, high impact and tear resistance, and high load bearing ability....
View Full Document
- Spring '07
- Materials Science, Tensile strength, high abrasion resistance, interfacial bone growth, short chain PMMA, low MW forms