碳纤维/羟基磷灰石骨植入复合材料的研究

【作者】 陶可；

【导师】 周科朝；

【作者基本信息】 中南大学 ， 材料学， 2004， 硕士

【摘要】 羟基磷灰石（hydroxyapatite，HA）／碳纤维生物复合材料是一种优良的生物硬组织替代材料，但由于羟基磷灰石与碳纤维的热膨胀系数和表面化学性质上的巨大差别，使HA／碳纤维复合材料的界面结合强度差，并且出现大量裂纹，导致HA／碳纤维复合材料力学性能较差，限制了其在人体内承载部位的应用。为克服以上问题，本文试图通过对碳纤维进行表面改性和碳纤维表面涂覆生物陶瓷等方法来改善HA／碳纤维的力学性能问题。 论文分别对未经硝酸处理的碳纤维和经过硝酸处理后的碳纤维表面电沉积磷酸钙进行研究，结果表明：两种碳纤维上的沉积产物均为CaHPO₄·2H₂O（DCPD），而产物的结构与形貌有所不同，硝酸氧化时间对磷酸钙沉积速率及质量也有明显影响。通过对HA／碳纤维复合材料的相成分、微观形貌与力学性能的研究表明：表面电沉积处理对碳纤维增强HA复合材料的性能是不利的，容易诱发HA的分解。未经任何处理的碳纤维复合羟基磷灰石会导致烧结不充分的情况出现。经过硝酸处理的碳纤维则与基体粘结不强，而由于纤维与基体力学相容性不好（热膨胀系数的不匹配）导致了纤维附近许多裂纹的产生。 采用对氨基苯甲酸对碳纤维表面进行处理，并进行生物矿化，研究表明其上能够矿化出纳米级细粒状存在的HA，与在其它表面矿化出的HA在形貌上有所不同。在表面矿化处理后的碳纤维增强HA复合材料中，基体与纤维粘结较好，且未产生裂纹。表面矿化的HA复合材料能够获得比热压法制备的HA／碳纤维复合材料更好的力学性能。更多还原

【Abstract】 Hydroxyapatite(HA)/Carbon fibers composite is one kind of the excellent hard tissue implants. However, the significant difference in heat expansion coefficient and surface chemical properties between hydroxyapatite and C-fibers leads to the poor bonding strength of the C-fiber/HA interface, and to the appearance of cracks, which results in the low reliability of the mechanical properties of the composite. These reasons limited the application of the composite in the bearing position in human body. The technology of surface treatment and coating calcium phosphate layer on C-fibers have been used in this paper in order to fabricate more mechanically reliable C-fiber reinforced HA composite.The electrodeposition on the untreated and nitric acid treated carbon fibers was studied. Result shows that CaHPO4 2H2O(DCPD) was obtained as the kind of calcium phosphate coating on two kinds carbon fibers, but their construction and morphology are different. It also shows that the time of oxidization has significant influence on eletrodeposition kinetics. In this paper, carbon fibers treated by para-aminobenzoic acid were used for forming a bioactive coating on the surface of carbon fibers. Result shows that C-fibers were coated by a thick layer of nano HA particles, with the morphology of spheric or hemispheric shape.The chemical constitution, micromorphology and bending strength of the composites have also been discussed in the paper. And the result shows that electrodeposition layer on carbon fibers is unfavorable to the HA/C-fiber composite by inducing the decomposition of HA. The untreated C-fibers/HA composite has a fatal disadvantage in incomplete sintering. It has a weak bond between the carbon fibers treated by nitric acid and matrix, and it has a lot of cracks around the C-fibers due to the difference in heat expansion coefficient. On the contrast, it has a strong bonding strength between the biomieralized carbon fibers and matrix. The better bending strength can be obtained from the biomieralized C-fiber/HA composite than that of other C-fiber reinforced.更多还原