Title

An investigation of process for preparing high-strength, high-modulus bone repairing material that is biodegradable

Date of Completion

January 2010

Keywords

Engineering, Materials Science

Degree

Ph.D.

Abstract

We report an investigation of modified pultrusion process for making a fully biodegradable/bioabsorbable composite mimicking the natural bone tissue. Metallic implants widely used today cause unwanted bone resorption due to its mismatch of stiffness when compared to natural bone. The hydroxyapatite / polylactic acid composite in our study is comprised of unidirectional polylactic acid fibers and partially oriented hydroxyapatite nano-needle reinforcements. Fundamental theological studies about anisotropic hydroxyapatite suspension under shear flow are discussed. The practical rheological information was gathered in designing the pultrusion process. An X-ray diffraction method was used to quantify the spatial orientation distribution of hydroxyapatite. It was found that the alignment of hydroxyapatite could be induced through the shear flow in this process. The alignment was also important to the increase of composite stiffness through the structure / property relationship study. ^