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Preparation and characterization of ceramic/polymer biomaterials
A research area that has received much interest in recent years is the development of ceramic/polymer biomaterials for the use as hard tissue replacements. Biomaterials that have seen much interest in the research community are the hydroxyapatite/poly-lactide biocomposites. Composites composed of these materials offer the advantages of being osteoconductive and resorbable. The current methods for preparing these biomaterials, however, are less than desirable. Many methods incorporate the use of the catalyst stannous octanoate and/or the use of solvents such as CHCl3, CH2Cl2 and THF. These methods require extreme care be taken to ensure the removal of any residual contaminants, due to human toxicity and the carcinogenic properties of these compounds.^ The research presented in this dissertation is directed by the discovery that solid hydroxyapatite can initiate the ring-opening polymerization of L-lactide without the use of any catalysts or solvents. This discovery has resulted in the development of a method for the formation of hydroxyapatite/poly-lactide biocomposites in a single step. Further advantages of this discovery include an improved interface between the hydroxyapatite and poly-lactide, and all preparation methods and processing are environmentally benign. ^ This dissertation describes research into the preparation and characterization of ceramic/polymer biomaterials, with specific interest devoted to hydroxyapatite/poly-lactide biocomposites. The kinetics of the ring-opening polymerization of L-lactide initiated by synthetic hydroxyapatite powder is investigated, resulting in a second order reaction rate that is first order in mole fraction of L-lactide and surface area of hydroxyapatite. ^ Building upon the discovery that solid synthetic hydroxyapatite can initiate the polymerization of L-lactide, I investigated several other sources of hydroxyapatite as polymerization initiators and the properties of the resulting biocomposites. One method utilizes anorganic bone, resulting in the development of a method to form anorganic bone/poly-lactide biocomposites with mechanical properties similar to original bone. A second method utilizes coralline hydroxyapatite to prepare a porous biocomposite with improved mechanical properties compared to literature values for control samples.^
Chemistry, Analytical|Chemistry, Organic|Chemistry, Polymer
Karr, Jeremy J, "Preparation and characterization of ceramic/polymer biomaterials" (2008). ETD collection for University of Nebraska - Lincoln. AAI3304243.