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The three-dimensional biodegradable chitosan fracture fixation materials to avoid other types of fractures the fixtures secondary surgery, stress shielding, the disadvantage of non-bacterial inflammatory response. In this thesis, using a variety of methods in order to meet the requirements of the of 3D chitosan rods in the use of fracture, enhancements the modified chitosan rods and research mechanism of enhanced modified. Chitin rods of high strength, bone nail is a novel, with independent intellectual property rights of Biomedical Materials, is of great significance in alleviating the fracture patient suffering, medical costs savings. (1) the use of chitin and chitosan deacetylation degree differences lead to both different solubility in dilute aqueous acid, prepared with layered overlay structure chitin fiber / chitosan three-dimensional composite rod, when the composite rods when under load, the stress by the chitosan matrix is ??passed to a fiber-reinforced body, in order to achieve the purpose of enhanced modified. Filter paper fiber surface is roughened, and enhance the mechanical riveting force between the fibers and chitosan matrix, and both occurred interfacial chemical reaction, generating a Schiff base, effective to increase the interfacial bonding strength of the composite material, thereby increasing the composite The mechanical properties of the bars. Using polyethylene amine phenylacetylene coated multi-walled carbon nanotubes, multi-walled carbon nanotubes uniformly dispersed in the matrix of chitosan can effectively bear the load. Further, put on to the multi-walled carbon nanotubes with a layer of water-soluble, magnetic \(2) sodium alginate, carboxymethylcellulose, chitosan polyanion electrolyte modified three-dimensional chitosan rods, the amino group on the molecular chain of chitosan, acetamido and polyanion electrolyte carboxylate functional group exists between strong electrostatic interaction, so that the material becomes more tightly, thereby improving the mechanical properties of the composite rods. (3) made by the bionic design had high strength sodium polyphosphate / chitosan three-dimensional composite rods, the bars Fangmu rings layered the superimposed structure belongs Liesegang Ring phenomenon; bars imitation bamboo hollow structure by controlling chitosan solution in lye clotting time; there is a strong electrostatic interactions and hydrogen bonding interactions between sodium polyphosphate and chitosan, chitosan matrix becomes more closely. Layered superimposed structure, imitation bamboo hollow structure composite rods electrostatic interaction between the three together, and greatly improve the mechanical properties of the bars. (4) Co60-γ-rays radiation induced reaction of chitosan molecular chain scission, reducing the molecular weight of the chitosan, the chitosan between the molecular chains entangled weakened ability of segments movement conducive shell crystal rearrangement of the glycan molecules, increase the degree of crystallinity of the chitosan, thereby improving the strength of the chitosan rods. The microwave radiation to produce thermal effects, the occurrence of thermal cross-linking reaction, the chitosan rods to form a network-shaped integral structure, improve the mechanical strength of the chitosan rods. (5) glutaraldehyde cross-linked modified chitosan rods and hydroxy apatite / chitosan three-dimensional composite sheet, the chitosan matrix formation the body network-like cross-linked structure, bars, layered overlay structure becomes more closely to reduce the particle size of the nano-hydroxyapatite. Chitosan rods under stress crack generated in a layer within the extensions, when the encounter another layer of passivation occurs, or deflected, to change the extension direction, tearing along between layers, the absorbed energy. The crosslinked chitosan rods layered superimposed structure becomes more closely, thus torn between the stress along the layer needs to consume more energy. Glutaraldehyde cross-linked chitosan Body Type network-like structure and the layered structure of the crack propagation mechanism rods improvement in mechanical properties. The mechanical properties of three-dimensional chitosan rods through the study of the subject has been greatly improved, from the effect of enhanced modified, sodium polyphosphate / chitosan biomimetic hollow bar, microwave radiation modified shell glycans bars as well as glutaraldehyde cross-linked modified chitosan rods better mechanical properties, are three ways to make the rod bending strength of about 180 MPa, the rod bending strength is about pure chitosan two times expected for clinical fractures and internal fixation.
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