【作者】 李皓；

【导师】 万怡灶；

【作者基本信息】 天津大学 ， 材料学， 2009， 博士

【摘要】 三维编织纤维增强复合材料具有强度高、整体性好等优异特性,但以聚醚醚酮（PEEK）为基体的复合材料制备存在较大困难,鲜有报道;三维编织碳纤维增强聚醚醚酮(C_3D/PEEK)、三维编织碳纤维增强环氧树脂(C_3D/EP)复合材料等因表面惰性而难于进行涂覆处理,限制了应用,故有必要对其进行表面改性。本课题研究纤维混编加热压制备C_3D/PEEK复合材料的工艺,并对该材料及用传统RTM工艺制备的C_3D/EP和二维编织碳纤维增强环氧树脂(C_2D/EP)复合材料进行等离子体处理,以改善其表面物理与化学性能。通过对C_2D/EP复合材料表面进行等离子体处理、导电膜沉积或离子注入后进行硫酸铜电镀和纳米复合电镀,得到性能和结合力优异的金属镀层;通过对C_3D/PEEK复合材料进行细胞实验和钙磷层沉积实验,为获得具有优异生物特性的表面层提供实验依据。研究结果表明,以混编纤维预干燥2 h后370℃、0.5 MPa真空熔融热压可获得表面状态良好、纤维浸渍充分的C_3D/PEEK复合材料,合适的碳纤维体积含量和表面氧化处理可显著提高材料的力学性能。接触角测试及XPS、AFM结果证实,随等离子体处理时间延长,几种编织复合材料亲水性均明显改善,这与试样的表面粗糙度和活性基团数量增加有关,但处理时间过长会破坏表面已形成的活性基团。形貌分析表明,以适当工艺可在几种复合材料表面形成具有明显金属光泽的金属离子注入层。研究证实,树脂中掺杂1%聚苯胺导电纳米线可使C_2D/EP复合材料电镀速度加快;随导电物沉积时间延长,C_2D/EP复合材料表面导电性能逐渐增大,而适当的等离子体处理和金属离子注入都会对C_2D/EP复合材料的后续电镀起到良好作用。硬度测试及SEM分析表明,普通硫酸铜电镀液中掺杂一定量纳米SiO2可使镀层显微硬度提高,且随掺杂量提高硬度增加,掺杂后材料表面电镀层晶粒显著细化,镀层致密度提高。细胞实验证实,在1.0×10⁴ /ml和2.0×10⁴ /ml两种成骨细胞种植密度下,C_3D/PEEK复合材料表面细胞数量均随培养时间延长而明显增加,材料表面有形态良好的细胞存在,MTT实验表明材料无毒性。SEM和EDS结果表明,经等离子体处理、钛离子注入及碱液处理后的C_3D/PEEK复合材料浸入1.5倍SBF中一段时间后均有钙磷化合物层生成,且沉积28天后其球状颗粒相比7天时更多且更为细小、均匀,在几种不同的预处理方式中,碱处理的试样其沉积量和Ca/P原子比均最高。总之,以混编加热压制备的C_3D/PEEK复合材料及RTM制备的C_3D/EP和C_2D/EP复合材料经适当处理后表面更具活性,可大大方便后续处理,并可获得良好的金属化和生物活性化效果,扩展了该类编织复合材料的应用范围。更多还原

【Abstract】 Three-dimensional braided composites are excellent materials for surgery, aviation and other applications because of their good properties such as high specific strength. But the preparation of three-dimensional braided carbon fiber reinforced PEEK (C_3D/PEEK) composites is difficult and with few reports. C_3D/PEEK, three-dimensional braided carbon fiber reinforced epoxy (C_3D/EP), two-dimensional braided carbon fiber reinforced epoxy (C_2D/EP) composites, and so forth, are unsuitable to be deposited due to their low surface free energy, poor wettability and poor adhesion. As a result, surface modification of these composites will be greatly helpful to their applications.In this paper, the fiber commingled braiding and hot-pressing process for the preparation of C_3D/PEEK composites was studied. The effects of the plasma treatment on the chemical and physical changes of C_3D/PEEK, C_3D/EP and C_2D/EP surfaces were investigated. C_2D/EP composites were plasma treated, deposited with thin electric layers or ion implanted, and then copper plated with sulfuric acid based solution or composite plated in order to obtain copper or composite coatings with good adhesion and properties. The in vitro cytotoxicity experiment and deposition of Ca-P layer on C_3D/PEEK surfaces were carried out to evaluate the feasibility of more biomedicine applications of the composites.It was shown that C_3D/PEEK composites with excellent appearances and good interfacial adhesions could be prepared by vacuum hot-pressing at 370℃and 0.5 MPa after 2 h pre-dryness. The mechanical properties of composites could be evidently improved by optimization of fibre volume fraction and surface oxidation.Appropriate plasma treatment would increase the hydrophilities of composites because of the increased roughnesses and active groups. Metal ion implanted layers on composite surfaces could be obtained after ion implantation.The copper electroplating rate would be improved after plasma treatment, metal ion implantation, conductive polymer doping in epoxy resin matrix of the composites, or deposition of conductive layer on C_2D/EP surfaces. Crystalline grains of the coatings were markedly refined by nano-SiO2 in the acidic sulfate copper plating bath and the ceramic particles caused an increase in hardness of coatings.Osteoblast cells on C_3D/PEEK surfaces increased in amount with prolonged cell seeding time and presented a good shape. Ca-P layers were deposited on C_3D/PEEK composites, which had been immerged into 1.5 SBF after different pre-treatments. The globular grains of Ca-P layers after 28 d deposition were smaller and more uniform than that after 7 d deposition. Both the amount of Ca-P deposit and Ca/P atom ratio after alkali treatment were higher than that after the other pre-treatments.In conclusion, after appropriate surface modifications, C_3D/PEEK, C_3D/EP and C_2D/EP composites were well activated, roughened, metallized or bioactivated and thus would be employed for more applications.更多还原