【作者】 李建；

【导师】 王玉林； 万怡灶； 黄远；

【作者基本信息】 天津大学 ， 材料学， 2005， 硕士

【摘要】 羟基磷灰石(HA)是人体和动物骨骼的主要无机成份,近二十年来,接近或类似于自然骨成份的无机生物医学材料的研究极其活跃,其中特别值得重视的是与骨组织生物相容性最好的HA活性材料的研究。为了探索生物性能和力学性能兼备的复合材料,本文提出HA复合材料的制备新思路:首先使用溶液法在较高浓度下制备HA粉体和HA纳米针晶,然后在合成的HA粉体的基础上探索制备两种新型HA复合材料(连续钛丝增强HA生物陶瓷复合材料和HA多孔坯体增强有机玻璃复合材料。)通过SEM、TEM、XRD、FTIR和EDS等现代分析方法,表征了HA粉体的形貌、物相组成,观察了HA陶瓷表面微观形貌和复合材料断口微观形貌,分析了界面反应产物和元素分布。本文研究了HA陶瓷烧结的影响因素,研究了Ti和HA之间的界面反应,并探讨了Ti丝增强HA复合材料和HA多孔坯体增强PMMA复合材料的制备工艺。通过溶液法制备HA纳米针晶时,反应体系和分散剂、溶液浓度、反应温度、pH值和陈化时间等因素对于HA粉体粒度和形貌有影响,通过对上述因素的控制可以获得HA纳米针晶。制备的HA粉体煅烧可得仅含HA和磷酸钙的生物陶瓷粉;升高pH值或延长陈化时间可以提高煅烧产物中HA的含量。使用钛(Ti)丝作为HA的增强相,采用铺层压制和注浆成型的方法制备了复合材料,在真空条件下烧结,获得了复合材料界面反应的初步结果。研究表明,注浆成型工艺可有效避免初始应力产生,Ti/HA复合材料由于反应过渡层的存在改善了热膨胀匹配,有效避免了基体裂纹的产生。EDS分析显示,Ti的远程扩散促进了HA基体分解和梯度过渡区的形成;Ti及其氧化物与HA界面反应剧烈,生成钛酸钙(CaTiO3)等界面反应产物。这类反应产物改善了界面结合和匹配,可作为金属-陶瓷复合材料的过渡层。界面反应层的厚度可通过钛丝的预处理得到控制。HA多孔坯体增强有机玻璃(PMMA)复合材料可以采用坯体预浸渍PMMA低粘度预聚体后,再原位聚合的方法制备,PMMA预聚体的粘度、原位本体聚合的温度是复合材料制备的关键因素。更多还原

【Abstract】 Hydroxyapatite(HA) is one of most important inorganic components. In recent20 years, the study of biomaterials like natural bone is active. HA was believed to bethe best materials for bone structure. In order to get a new material which should hasboth good mechanical properties and bioactivity, new methods of preparing HAcomposites are raised. At first, HA powders and needle-like HA crystals were madeby a wet precipitation method. The resulting powders were used to prepaere two kindsof new composites—titanium fiber reinforced HA composite and porous HA prepregreinforced PMMA composite.In this paper, microstructure was observed by SEM and TEM, phase structurewas analysed by XRD and FTIR, and element content was analysed by EDS.Influence of HA sintering was studed and interface reaction between Ti and HA wasalso inverstigated. New composite preparation approaches were discussed.HA powders were prepared by wet precipitation method in this paper. The effectof solution concentration, temperature, pH value and aging time affected thegranularity and morphology of HA powders. Bioceramic powders consisting of HAand Ca3(PO4)2 were received by calcining wet precipitated powders. Increasing pHvalue or prolonging ageing time was found to increase HA content in the resultedpowder mixture.A new titanium fiber reinforced hydroxyapatite biocomposite was fabricated byvacuum sintering and slip casting. Long fibers of titanium were incorporated in amatrix of hydroxyapatite to toughen the hydroxyapatite. The interface wasinvestigated for microstructure and chemical composition. Slip casting avoided theinitial stress and the interface reaction of titanium and hydroxyapatite eliminated thedifference of thermal expansion. Diffusion of titanium promoted the decomposition ofhydroxyapatite and formation of transition area. Titanium and its oxid reacted withhydroxyapatite, created products such as calcium titanate, and so on. The productsimproved interface combination and matching, which can be used as transition areafor metal-ceramic composites. The interface reaction layer can be controlled bytitanium surface treatment.HA porous prepreg reinforced PMMA composites were prepared byimpregnation method and in situ mass polymerization. Viscosity of PMMAprepolymer and temperature of in situ mass polymerization were critical to thepreparation of composites.更多还原