【作者】 刘文斌；

【导师】 屈树新；

【作者基本信息】 西南交通大学 ， 材料学， 2005， 硕士

【摘要】 本研究针对具有优良生物相容性的羟基磷狄石（HA）力学性能不足,不能解决临床承力部位的替换或修复的问题,采用加入韧性相明胶改善HA材料的力学性能。 本研究在湿法合成的基础上加入gelatin,解决两相均匀分布,研究并优化制备HA/gelatin复合材料,以及gelatin交联的最佳工艺参数;实验结果表明反应过程中pH应控制在gelatin的等电点之间,本实验选择pH=9,所制备的复合材料既利于HA的生成,又有利于gelatin在反应过程中的沉积;利用戊二醛（GA）对复合材料浆料gelatin进行交联,优化加入GA的量和浓度以及gelatin交联的最低浓度,实验结果表明gelatin和GA的最低浓度为5%（wt%）,GA与复合材料浆料间的体积比为15:100,交联效果最佳;制备经GA交联gelatin的HA/gelatin复合材料,自制的成型设备可以保证样品在干燥过程中不出现开裂,干燥前后样品保持形状能力较佳; 本实验采用XRD分析样品的相成份,利用SEM观察样品断面的微观结构,利用FT-IR来确定样品中HA中的Ca²⁺和gelatin中COO^-之间化学结合的存在;通过TG-DTA对样品gelatin的含量进行测量以及两相的结合;采用万能力学试验机测试样品的力学性能,利用模拟体液（SBF）的体外模拟实验考察样品的降解,以及样品中HA和gelatin诱导类磷灰石在其表面的沉积。 XRD结果表明HA/gelatin复合材料,无机相为HA,没有其它磷酸钙的出现,gelatin的加入不会对HA的生成产生影响,但gelatin的存在,使得HA主极大衍射峰的半高宽加大,HA晶粒尺寸细小,gelatin的含量越多,晶粒尺寸越细小;同时gelatin由于与HA的结合,导致HA晶胞畸变,所对应的衍射峰位置位移。SEM观察所形成的gelatin纤维网状结构,阻碍了样品在干燥过程中的收缩,因此在样品断面出现了一些细小的裂纹。从红外图谱中1339cm^-1的红移可知,HA更多还原

【Abstract】 The study aims at the poorer mechanical property hydroxyapatite(HA) biomaterials although they possess the excellent biocompatibility. It is difficult to be used as bone replacement at the loading site in clinic. In the present study, the mechanical property of hydroxyapatite has been improved by adding plastic phase gelatin.Hydroxyapatite/Gelatin was synthesized by adding gelatin solution into the reactive solution when HA was formed. The homogenous composite was obtained due to two phases were co-precipitated in reactive solution. The optimal technical parameter to prepare HA/gelatin composite, crosslink of gelatin and formed and dried were obtained. The results suggested that pH played an importuned role during synthesis of HA/gelatin composite. It is benefit to co-precipitation of HA and gelatin when the pH value of reactive was about equipotential point of gelatin. In the present study, pH=9 was chosen. The lowest concentration of crosslinkage, glutaraldehyde (GA), and the lowest concentration of gelatin in the slurry of HA/gelatin were all 5% (wt%). The volume proportion of GA and the slurry of HA/gelatin was 15:100. The composite do not craze and distort in the drying process using homemade moulding equipment.The phase components were analyzed by X-Ray Diffraction (XRD). The microstructure of composite was observed by Scanning Electronic Microscopic (SEM). The chemical bonding between hydroxyapatite and gelatin were analyzed by Fourier-transformed infrared spectrophotometry FT-IR and Differential Thermal Analysis (DTA). The content of gelatin in the composite was calculated from TG data. The mechanical properties ofcomposites were tested using Instron Material Testing Machine. The in vitro biodegradation of composites were investigated in stimulated body fluid (SBF). It has found that a layer of apatite was formed on the composite surface when they were immersed in SBF.The XRD results demonstrated that the inorganic phase of hydroxyapatite/gelatin composites was HA in the present experiment. HA crystal grains sizes become smaller due to adding gelatin. Its sizes was more thinner, the more gelatin was added. The chemical bonding between HA and gelatin gave rise to the HA crystal lattice aberrance, which were determined by the increase of diffraction angle of various. SEM observation showed that there were some thin cracks on the fracture section of composites. It maybe gelatin fibrous prohibited the composite shrinkage. The FT-IR results of red-shift of 1339cm"1 confirmed the chemical bonding between HA and gelatin. TG results showed that the content of polymer of HA/gelatin-9+GA was more than that of HA/gelatin-9 and HA-9. It indicated that the gelatin content in composite increased with the adding of GA to promote the net-like gelatin formation. The gelatin content of HA/gelatin-9+GA was 32% (the experiment design is 33.3%). The exothermic peak of HA/gelatin-9+GA composite moved to 500°C to 600°C, which was higher to precipitate that of HA/gelatin-9. It confirmed that there were more stable structure in HA/gelatin composite when GA was added. The mechanical measurement showed that the compressive strength of HA/gelatin-9 was the highest among the three specimens. But HA and HA/gelatin-9 behaved the brittle fracture. HA/gelatin-9 +GA behaved the plastic fracture although their compressive strength decreased. In vitro experiment showed that HA/gelatin-9 and HA-9 were更多还原