| Bone repair composite material has become one of the hot spots in the field of biomedical composite materials. The common repair method, allogeneic bone transplantation exist problems of immune rejection, autologous bone graft are difficult predicament, and with a metal material bone material as a bone repairing material prone to "stress shielding effect". Therefore, the development of which can meet the requirements on the mechanical properties of bone repair, but also has biological activity, can in the in vivo degradation and absorption, to avoid secondary operation characteristics of bone repair materials is bound to become the focus of research in the field of bone repair. With biological activity of inorganic particles and polylactic acid as matrix, reinforced with carbon fiber as the matrix, preparation of the carbon fiber reinforced poly(lactic acid)/inorganic particle composite materials. The composite material has the characteristics of high strength, good biological activity, and biodegradability. The preparation of the composite material to avoid the material degradation of poly(lactic acid)(PLA) acid product of acid is too large and cause inflammation of the problem, is expected to become meet the demands of clinical bone repair a new bone repair material.Using JMXRJ as modifier, the surface modification of poly(lactic acid)(PLA) and inorganic particles were prepared by the solution blending method, and the PLA/ inorganic particle composites were prepared. Chemical structure changes of PLA and inorganic particles before and after modification were analyzed by using FTIR; The effects of JMXRJ and inorganic particles on the thermal properties of PLA were studied by DSC; The hydrophilic property of PLA and modified PLA materials with different content of JMXRJ were analyzed by contact angle tester. The effect of inorganic particles on the crystallinity of JMXRJ/PLA materials was studied by using XRD. The effects of different ratio of JMXRJ and inorganic particles on the mechanical properties of PLA materials were studied, and the mechanical properties of the composites were better when the content of JMXRJ/PLA/ inorganic particles was determined by 5/100/10; The morphology of crystal PLA, JMXRJ/PLA and JMXRJ/PLA/inorganic particles under different temperature after isothermal crystallization of 20 min observed by polarizing microscope. Predicting the relative crystallinity of the material at different cooling rate in the non isothermal cold crystallization by BP neural network, which has an important reference value for the study of crystallization properties.On the basis of the above, the use of 0°and 90°alternate way to lay the layer of pre impregnated material, forming process: materials in under the pressure of 10 MPa cold pressing 30 min, then in the hot pressing temperature for 145℃and a pressure of 13 Mpa, hot pressing time is 1.5h, and cold pressed to room temperature. The bending strength of CF/PLA/ inorganic particle composite laminates is 312.74 MPa, the flexural modulus is 9.0233×104MPa, the impact strength is 143.47KJ/m2, and the mechanical strength of the human skeleton is completely satisfied.The degradation properties of CF/PLA/ inorganic particle composites prepared by simulated body fluid were studied. The experimental condition is 37±1℃, the experimental period is 15 weeks, and the performance of the composite is tested and analyzed. With the extension of the experimental period, CF/PLA/inorganic particle composite mechanical properties and the relative molecular weight of PLA in CF/PLA/ inorganic particle composite decreases, but the addition of inorganic particles inhibits the PLA’s autocatalytic effect, make the degradation rate are decreased; Composite mass loss rate and volume change rate with the extension of time and increase gradually, and immersion medium of pH stability in human acidity allowed range, in the degradation of 15 weeks after the flexural strength of the materials still reached 170.875 MPa. To simulate the effect of water on the performance of bone implant materials in human body, respectively, Fick model and BP artificial neural network model is established for composite material in simulated body fluid amount of moisture in changing with time curve is studied; The moisture absorption behavior of the composite is in line with the single phase Fick moisture absorption model. At the same time, the moisture absorption of the material can be predicted by the BP network, which provides a new idea for the study of the properties of the material. |
