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Polymer Matrix Composite Biomaterials
A composite material is a material consisting of two or more chemically distinct constituents, on a macroscale, having a distinct interface separating them. In practice, polymer matrix composites consist of fiber and particulate reinforced composites as biomaterials.
Most of the composite materials are designed to provide improved mechanical properties such as strength, stiffness, toughness and fatigue resis¬tance. Therefore, they are frequently used as biomaterials for orthopaedic applications where mechanical properties are a serious concern.
Much effort has been invested in the development of composite biomate¬rials for the repair or replacement of hard tissue. Besides the general considera¬tion of biocompatibility, the specific consideration for bone replacement mate¬rials is of biomechanical nature: the biomaterials should possess the mechanical properties necessary for a proper performance in their function. Other proper¬ties, such as biodegradation and the ability to bond to bone ( so-called "bone-bonding" property) , are some additional favourable assets. The bone bonding property can be defined as "the establishment by physicochemical processes of a continuity between implant and bone matrix". Bone bonding properties -often called "bioactivity"- have been proven to be of great benefit for bone replacement materials.
The use of polymer matrix composites for bone replacement may offer the advantages of avoiding the problem of stress shielding ( a problem encountered when using high modulus metal implants) , eliminating the need for a second surgical procedure to remove the implants if the implants can be biodegradable and eliminating the ion release problem of metal implants. The possibility to make the composites as strong as cortical bone and to improve the material s bioactivity or bone bonding activity by adding a secondary reinforcing phase makes the composites very attractive. Fibers and ceramic filler particles have been used to reinforce the polymer materials as well as to improve the bone-bonding properties of the composites.
1- Fiber Reinforced Composites
Carbon fiber, aramid ( Kevelar) , and glass fiber usually possess very high strength and stiffness and therefore have been frequently used to reinforce poly¬mers such as epoxy resin, polyetheretherketone ( PEEK), polysulfone ( PS), polymethyl methacrylate ( PMMA) , poly( lactide) , poly( glycolide) , polycap¬rolactone
المادة المعروضة اعلاه هي مدخل الى المحاضرة المرفوعة بواسطة استاذ(ة) المادة . وقد تبدو لك غير متكاملة . حيث يضع استاذ المادة في بعض الاحيان فقط الجزء الاول من المحاضرة من اجل الاطلاع على ما ستقوم بتحميله لاحقا . في نظام التعليم الالكتروني نوفر هذه الخدمة لكي نبقيك على اطلاع حول محتوى الملف الذي ستقوم بتحميله .
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