医用镁合金可降解高分子材料基复合材料表面改性研究

发布时间：2018-03-04 01:25

本文选题：纯镁　切入点：镁合金　出处：《华南理工大学》2013年硕士论文　论文类型：学位论文

【摘要】：镁合金因其良好的生物相容性、生物降解性以及力学相容性等优势，是理想的新型可降解生物医用金属材料。但由于人体生理环境具有较强的侵蚀性，镁合金植入后存在降解过快及一系列次生问题，因此对镁合金进行生物降解控制具有重要意义。本文以高纯镁（HP-Mg）和AZ91D镁合金为研究对象，选取聚左乳酸（PLLA）以及分别以MgO和Mg(OH)_2为增强相的PLLA基复合材料为涂层材料，对医用镁合金可降解高分子材料基复合材料表面改性技术进行了较为系统的探索研究。论文主要研究工作及结论如下：首先，对PLLA有机溶剂进行了筛选，从PLLA溶解速率、溶液涂覆效果（涂层均匀性、致密度及浸涂次数-涂层厚度函数关系）的角度优选出最佳溶剂配方，即环氧氯丙烷与丙酮混合体积比为2:1的均匀混合物。其次，利用项目组自有知识产权技术（发明专利申请号201210320035.4），以涂层防护性能为主要考核指标，实现了对PLLA浓度、浸涂次数和浸涂温度等主要工艺参数的优化；基于PLLA涂覆研究结果，对MgO/PLLA和Mg(OH)_2/PLLA复合材料涂覆技术进行了较为系统的研究，探明了MgO和Mg(OH)_2添加量对涂覆效果尤其是涂层耐蚀性的影响规律，锁定了其最佳添加量。最后，，对典型试样，包括阳极极化处理前后的空白试样，阳极极化处理前后最佳涂覆工艺条件制备的1）PLLA涂层试样、2）MgO/PLLA复合材料涂层试样和3）Mg(OH)_2/PLLA复合材料涂层试样进行了综合性能评价。基于测试介质颜色转变的耐蚀性快速检测、现代电化学动电位极化曲线测试以及体外生物降解行为研究结果表明：1）适量MgO或Mg(OH)_2增强相的添加均能显著提高PLLA涂层的降解防护性能；2）适量MgO或Mg(OH)_2增强相的添加有利于降低PLLA生物降解产生的酸化效应；3）阳极极化前处理有利于提高涂层的防护性能。涂层/基体结合力测试结果表明：1）涂覆状态下，PLLA涂层、MgO/PLLA和Mg(OH)_2/PLLA复合材料涂层与基体的结合力无明显差异，但阳极极化前处理对增强涂层/基体结合力有益；2）体外生物降解测试期间，复合材料涂层与基体的结合力远优于PLLA涂层。SEM分析结果表明：PLLA涂层及PLLA基复合材料涂层厚度均匀，结构致密。
[Abstract]:Magnesium alloy is an ideal new biodegradable biomedical material because of its good biocompatibility, biodegradability and mechanical compatibility. The degradation of magnesium alloy is too fast and a series of secondary problems exist after implantation, so it is very important to control the biodegradation of magnesium alloy. In this paper, high purity magnesium (HP-Mg) and AZ91D magnesium alloys were studied. Poly (L-lactic acid) and PLLA matrix composites with MgO and Mg(OH)_2 as reinforcing phases were selected as coating materials. The surface modification technology of medical magnesium alloy degradable polymer composites was studied systematically. The main research work and conclusions are as follows:. Firstly, the PLLA organic solvent was screened, and the optimum solvent formulation was selected from the angles of PLLA dissolution rate, solution coating effect (coating uniformity, density and the relationship between coating thickness and density). That is, the mixed volume ratio of epichlorohydrin and acetone is 2: 1. Secondly, using the intellectual property technology of the project group (invention patent application no. 201210320035.4) and taking the protective performance of the coating as the main evaluation index, the main technological parameters such as PLLA concentration, times and temperature of the coating are optimized. Based on the results of PLLA coating, the coating technology of MgO/PLLA and Mg(OH)_2/PLLA composites was systematically studied. The effect of the amount of MgO and Mg(OH)_2 on the coating effect, especially the corrosion resistance of the coating, was investigated, and the optimum amount of the coating was locked out. Finally, for typical samples, including blank samples before and after anodic polarization treatment, The comprehensive properties of the 1D PLLA / PLLA composite coating sample and the 3Mg-OHH + 2 / PLLA composite coating sample prepared under the optimum coating conditions before and after anodic polarization treatment were evaluated. Based on the rapid corrosion resistance test of the color transformation of the medium, the corrosion resistance of the coated sample was evaluated. The results of modern electrochemical potentiodynamic polarization curve test and biodegradation behavior in vitro showed that the addition of appropriate amount of MgO or Mg(OH)_2 reinforcements could significantly improve the protective performance of PLLA coatings on degradation and degradation. The addition of appropriate amount of MgO or Mg(OH)_2 reinforcements could significantly improve the degradation protection performance of PLLA coatings. Anodic pretreatment can improve the protective performance of the coating. The results of coating / substrate adhesion test show that the coating is coated with MgO / PLLA and Mg(OH)_2/PLLA composite coatings under the condition of 1: 1). There was no significant difference in adhesion with the matrix. However, during the in vitro biodegradation test, the adhesion between composite coating and substrate was much better than that of PLLA coating. The results showed that the thickness of PLLA coating and PLLA matrix composite coating were uniform. The structure is compact.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TG174.46

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