碳纳米管的功能化及其对PMMA骨水泥热学和力学性能影响的研究分析

发布时间：2018-06-17 20:02

本文选题：PMMA骨水泥 + 碳纳米管　；参考：《山东大学》2015年博士论文

【摘要】：PMMA骨水泥是由粉末状的聚甲基丙烯酸甲脂(PMMA)和液态单质的甲基丙烯酸甲酯(MMA)发生聚合反应生成的一种高分子共聚物。PMMA骨水泥能牢固的固定人工移植体,并具有良好的手术可操作性,因此被看作是髋关节置换、膝关节置换及牙科等手术的“黄金标准”。但是,PMMA骨水泥的抗拉强度(24～50MPa)远低于其抗压强度(73-120MPa),导致骨水泥在承受较大荷载时容易出现脆性断裂。在循环荷载下,PMMA骨水泥壳与宿主骨的界面,或者骨水泥壳与移植体的界面,容易产生疲劳裂纹,引起疲劳性断裂。同时,PMMA骨水泥的聚合反应是一个高发热反应,平均每克甲基丙烯酸甲酯(MMA)释放大约554焦耳的热量,局部温度高达80-120℃,比人体正常的许可温度(50-60℃)高出30～40℃,容易造成骨水泥附近的人体组织的热坏死。碳纳米管(CNT)拥有优异的物理和力学性能而被认为是复合材料的理想增强相,已成为当前最吸引科学界眼球的材料。CNT能赋予复合材料许多新的功能,可以很好的代替碳纤维等传统材料,充当骨水泥材料的增强体,发展成具有导热性良好、抗弯以及耐疲劳等多项功能的碳纳米管／骨水泥(CNT/PMMA)复合材料。但是,碳纳米管间的范德华力使得碳管极易团聚缠绕在一起,不容易被均匀分散在骨水泥基体中,影响了与基体的界面结合强度,严重的限制了碳纳米管优异性能的发挥。如何将CNT均匀的分散到骨水泥基体中,成为首先要解决的关键问题。本文首先采用UV/Fenton 3步纯化法清除原始碳管携带的无定型碳和催化剂等杂质,然后采用绿色的功能化方法对碳纳米管进行修饰改性,即利用葡萄糖水热处理过程中形成的芳香族化合物成功的在碳纳米管的表面织上了一层纳米尺度的包覆层,改变了传统的聚合物单体的方法来对碳纳米管进行功能化。经过拉曼光谱表征,水热处理后的碳纳米管在1580cm-1处表现出特征强峰,证明碳纳米管的结构并未受到破坏。经傅里叶红外光谱表征,在碳纳米管红外光谱图上的1211 cm-1处、1601 cm-1处和1736 cm-1处均表现出强峰,分别代表碳纳米管表面成功的携带上了羟基(-OH),羰基(C=0)和羧基(-COOH)等功能性官能团。通过Origin 9.0和XPSPEAK 4.1软件对功能化前后碳纳米管表面的C元素和O元素的XPS精细谱图进行分峰处理,可以判断碳纳米管表面的C1s峰被分为五个峰,分别为C1-C5峰,其中C3峰(286.2eV)归属为羟基,C4峰(287.5eV)归属为酮羰基,C5峰(289.4 eV)为归属为羧基。碳纳米管表面的O1s峰分为01-03三个峰,其中,O1(531.5 eV)可归属为醌或酮羰基,02(532.6 eV)可归属为酯或酸酐中的O-C=O基团,而03(533.7eV)可归属为醚或酚中的C-O基团,结果表明CNT经葡萄糖水热法处理后,在其管壁上成功的枝接上了羟基,羰基和羧基等功能性官能团。通过TEM透射电镜扫描的图像,可以测得碳管表面成功的被织上了一层12nm～22nm厚的亲水性的碳包覆层。采用超声波震荡的方法将功能化的碳纳米管与MMA溶液混合均匀后,加入PMMA粉末以及BPO和DMPT等催化剂,发生聚合反应生成CNT/PMMA骨水泥。根据丙烯酸骨水泥的国际标准ISO-5833-2002的规定,测定了骨水泥在掺入碳管后的聚合最高温度、热坏死系数、固化时间和导热系数等热学性能参数。对测试数据进行方差分析(检验假设a=0.01),实验结果表明：碳纳米管能极大的改善骨水泥的热学性能。根据ASTM E399-06和ASTMF2118-01a的规范要求,对骨水泥的抗压、抗弯、断裂韧性和疲劳强度进行了测试,并借助于威布尔(Weibull) 3参数分析方法对骨水泥的疲劳寿命建立了预测模型。对Paris公式进行改进,进行了带有预制裂纹的CNT/PMMA复合骨水泥弯曲疲劳试验,得出疲劳裂纹扩展的重要参数C、m值,研究了掺加碳纳米管后骨水泥的疲劳裂纹的扩展规律。力学测试结果表明,当掺加质量分数3%的的碳管后,跟标准试件(未掺加碳管的骨水泥)相比,CNT/PMMA骨水泥的抗压强度增长幅度较小,但是抗弯强度、断裂韧性和疲劳寿命均有显著性的提高,疲劳裂纹的扩展速率明显趋缓。通过对碳纳米管的功能化处理,提高了碳纳米管与骨水泥之间的界面结合强度,优化骨水泥的热学和力学性能,获得了具有良好力学性能的碳纳米管／骨水泥复合材料。
[Abstract]:PMMA bone cement is a polymer copolymer of powdered polymethyl methacrylate (PMMA) and liquid monosaplastic methyl methacrylate (MMA). A polymer copolymer of high molecular weight,.PMMA bone cement can be firmly fixed, and has good operative maneuverability. Therefore, it is regarded as hip replacement, knee replacement and dentistry. However, the tensile strength of PMMA bone cement (24 ~ 50MPa) is far lower than its compressive strength (73-120MPa), which leads to brittle fracture of the bone cement when it bears large load. Under cyclic loading, the interface between the PMMA bone cement shell and the host bone, or the interface between the bone cement shell and the transplant, is easy to produce fatigue cracks. It causes fatigue fracture. At the same time, the polymerization of PMMA bone cement is a high fever reaction, with an average of about 554 joules per gram of methyl methacrylate (MMA). The local temperature is up to 80-120 degrees C, higher than the normal permissive temperature of the human body (50-60 degrees C) at 30~40 degrees C, which is easy to cause thermal necrosis of human tissues near the bone cement. CNT, which has excellent physical and mechanical properties, is considered to be the ideal enhancement phase of composite materials. It has become the most attractive material to attract scientific attention..CNT can give the composite a lot of new functions. It can replace the traditional materials such as carbon fiber, and act as an enhancement of bone water mud material. It has developed into good thermal conductivity and resistant to heat. Carbon nanotubes / bone cement (CNT/PMMA) composite materials such as bending and fatigue resistance, however, the Fan Dehua force between carbon nanotubes makes the carbon nanotubes very easy to be entangled together, not easily dispersed in the bone cement matrix, affecting the bonding strength with the matrix, which seriously restricts the excellent performance of the carbon nanotubes. How to disperse the CNT evenly into the bone cement matrix is the key problem to be solved first. Firstly, this paper uses the UV/Fenton 3 step purification method to clear the amorphous carbon and catalyst carried by the original carbon tube, and then modifies the carbon nanotubes by the green functionalization method, that is, using the glucose water heat treatment process. The formation of aromatic compounds successfully woven a layer of nano scale coating on the surface of carbon nanotubes, changing the traditional method of polymer monomers to function carbon nanotubes. Through Raman spectroscopy, the carbon nanotubes after hydrothermal treatment showed a strong characteristic peak at 1580cm-1, proving the structure of carbon nanotubes and the structure of carbon nanotubes. The FTIR was characterized by a strong peak at 1211 cm-1, 1601 cm-1 and 1736 cm-1 on the carbon nanotube infrared spectrum. The functional functional groups such as the hydroxyl group (-OH), carbonyl (C=0) and carboxyl (-COOH) on the surface of the carbon nanotube were successfully carried on the surface of the carbon nanotube. The functions of the Origin 9 and XPSPEAK 4.1 software were obtained. The C element and the XPS fine spectrum of the O element on the surface of the carbon nanotube are divided into five peaks, which can be divided into five peaks, respectively, the C3 peak (286.2eV) belongs to the hydroxyl group, C4 peak (287.5eV) belongs to the carbonyl group of ketone, and the C5 peak (289.4 eV) belongs to the carboxyl group. The O1s peaks on the surface of the carbon nanotubes are divided into those of the carbon nanotubes. 03 three peaks, in which O1 (531.5 eV) can belong to quinone or ketone carbonyl, 02 (532.6 eV) can belong to the O-C=O group in ester or anhydride, and 03 (533.7eV) can belong to the C-O group in ether or phenol. The results show that after CNT is treated by glucose hydrothermic method, the functional groups such as hydroxyl, carbonyl and carboxyl groups on the wall of the tube are successfully connected to the functional groups such as carboxyl and carboxyl groups. Through TEM, the functional groups such as carboxyl and carboxyl groups are attached to the wall of the tube. A layer of 12NM to 22nm thick hydrophilic carbon coating was successfully woven on the surface of the carbon tube by transmission electron microscopy. The functionalized carbon nanotubes were mixed evenly with the MMA solution by ultrasonic oscillation, and the PMMA powder and the BPO and DMPT catalysts were added to produce the CNT/PMMA cement. According to the international standard ISO-5833-2002 of acrylic bone cement, the maximum temperature, thermal necrosis coefficient, curing time and thermal conductivity of the cement after adding carbon tube are measured. The test data is analyzed by variance analysis (test hypothesis a=0.01). The experimental results show that carbon nanotubes can greatly improve the heat of bone cement. According to the specifications of ASTM E399-06 and ASTMF2118-01a, the compression, bending, fracture toughness and fatigue strength of bone cement were tested. The prediction model of fatigue life of bone cement was established by means of Weibull (Weibull) 3 parameter analysis method. The Paris common formula was improved, and the CNT/PMMA complex with prefabricated cracks was carried out. The important parameters C and m of the fatigue crack propagation are obtained by the bending fatigue test of the bone cement, and the fatigue crack propagation law of the cement with carbon nanotubes is studied. The mechanical test results show that the compressive strength of CNT/PMMA cement is increased compared with the standard specimen (unmixed tube bone cement) after adding the mass fraction of 3% carbon tube. The long range is smaller, but the flexural strength, fracture toughness and fatigue life are improved significantly, and the propagation rate of fatigue crack is obviously slowed down. Through the functionalization of carbon nanotubes, the interfacial bonding strength between carbon nanotubes and bone cement is improved, the thermal and mechanical properties of the bone cement are optimized, and good mechanical properties have been obtained. Able carbon nanotube / bone cement composite.
【学位授予单位】：山东大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TQ172.1;TQ127.11;TB383.1

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