镁合金丝编织结构增强聚乳酸复合材料的制备及性能研究
发布时间：2018-09-06 06:38
【摘要】：聚乳酸的韧性差,降解产物呈酸性,缺乏骨结合力；镁合金强度高,但降解速率过快,研制各种镁合金与聚乳酸的复合材料是解决这些问题的有效途径。本文对镁合金丝进行二维编织,利用热压成型工艺制备出了镁合金丝编织结构增强聚乳酸复合材料,获得了最佳成型工艺参数,研究了编织角和镁合金丝体积分数对复合材料力学性能的影响,分析了镁合金丝表面微弧氧化处理对复合材料拉伸强度和剪切强度的影响,并对复合材料在模拟体液中的降解性能进行探索,结果如下：对比研究了两种不同镁合金丝编织结构增强聚乳酸复合材料的制备过程,确定了镁合金丝编织增强结构为二维二轴,且结构形式为1×1；在系统研究了热压工艺参数对复合材料弯曲强度影响的基础上,获得了复合材料的最佳成型工艺,即热压温度165℃C、热压压力2.6MPa和保压时间20min。编织角和镁合金丝体积分数对复合材料的力学性能有显著影响。编织角保持30°不变时,增大镁合金丝体积分数(0-12%),复合材料的拉伸强度、弯曲强度、横向剪切强度和冲击韧性增大,镁合金丝体积分数为12%时,分别是纯聚乳酸的1.6、1.8、1.6和2.8倍；镁合金丝体积分数保持10%不变时,增大编织角(15°-60°),复合材料的拉伸强度和弯曲强度减小,而横向剪切强度和冲击功呈现先增大后减小的趋势,并在45°时达到最大值,分别为75.6MPa和0.23J；通过与镁合金丝定向增强聚乳酸复合材料对比研究,发现采用镁合金丝编织结构强化有利于改善复合材料纵向剪切性能。镁合金丝微弧氧化处理可改善复合材料中两组元的界面结合性能,充分发挥镁合金丝的强化作用,编织角30°、镁合金丝体积分数12%的复合材料拉伸强度达到80.4MPa,比镁合金未微弧氧化的高13.7MPa；模拟体液浸泡4周过程中,纯聚乳酸的浸泡液pH值保持下降趋势,而复合材料浸泡液pH值先下降,1周左右会有所上升,并在4周时基本保持稳定。编织角30°、镁合金丝体积分数7%的复合材料和纯聚乳酸降解8周后的剩余弯曲强度分别为56MPa和31MPa,复合材料弯曲强度降低幅度小。复合材料中镁合金丝降解主要集中在微弧氧化陶瓷层膜上,丝材基体腐蚀不明显,而其聚乳酸组元分子量从5.5万下降到3.9万,但高于纯聚乳酸(3万),说明镁合金丝的存在能缓解聚乳酸的降解。
[Abstract]:The toughness of poly (lactic acid) is poor, the degradation products are acidic and lack of bone adhesion, and magnesium alloy has high strength, but the degradation rate is too fast. It is an effective way to solve these problems by developing various kinds of composite materials of magnesium alloy and polylactic acid. In this paper, two dimensional braiding of magnesium alloy wire was carried out, and the braided structure reinforced poly (lactic acid) composite was prepared by hot pressing process, and the optimum forming process parameters were obtained. The effects of braiding angle and volume fraction of magnesium alloy wire on the mechanical properties of the composites were studied. The effects of micro-arc oxidation on the tensile strength and shear strength of the composites were analyzed. The degradation properties of the composites in simulated body fluid were explored. The results were as follows: the preparation process of two different magnesium alloy wire braided structure reinforced PLA composites was studied. The braided reinforced structure of magnesium alloy wire is determined to be two dimensional biaxial, and the structure form is 1 脳 1. Based on the systematic study of the influence of hot pressing process parameters on the bending strength of the composite, the optimum molding process of the composite is obtained. The hot pressing temperature is 165 鈩，
本文编号：2225550
[Abstract]:The toughness of poly (lactic acid) is poor, the degradation products are acidic and lack of bone adhesion, and magnesium alloy has high strength, but the degradation rate is too fast. It is an effective way to solve these problems by developing various kinds of composite materials of magnesium alloy and polylactic acid. In this paper, two dimensional braiding of magnesium alloy wire was carried out, and the braided structure reinforced poly (lactic acid) composite was prepared by hot pressing process, and the optimum forming process parameters were obtained. The effects of braiding angle and volume fraction of magnesium alloy wire on the mechanical properties of the composites were studied. The effects of micro-arc oxidation on the tensile strength and shear strength of the composites were analyzed. The degradation properties of the composites in simulated body fluid were explored. The results were as follows: the preparation process of two different magnesium alloy wire braided structure reinforced PLA composites was studied. The braided reinforced structure of magnesium alloy wire is determined to be two dimensional biaxial, and the structure form is 1 脳 1. Based on the systematic study of the influence of hot pressing process parameters on the bending strength of the composite, the optimum molding process of the composite is obtained. The hot pressing temperature is 165 鈩，
本文编号：2225550
本文链接：https://www.wllwen.com/kejilunwen/cailiaohuaxuelunwen/2225550.html
