陶瓷粉体表面改性及其树脂基复合材料的组织与性能研究

【作者】 尤姝黎；

【导师】 杨振国；

【作者基本信息】 复旦大学 ， 材料学， 2008， 硕士

【摘要】 陶瓷/树脂基复合材料综合了有机材料的优点（质轻、耐冲击、韧性好、易加工等）和无机材料的特性（高强高硬度、热稳定性好、抗腐蚀等）。因此,陶瓷/树脂基复合材料受到了科学家的广泛关注,应用于许多领域。在本课题中,详细地研究了三种复合材料体系:纳米Si02/拼混树脂复合材料、纳米Al₂O₃/拼混树脂复合材料和TiB₂-Al₂O₃/拼混树脂复合材料的制备方法、固化工艺和复合材料的力学及热性能;同时,还研究了三种粒子的表面改性对复合材料结构和性能的影响。首先,采用偶联剂γ-氨丙基三乙基硅烷（KH550）、γ-（2,3-环氧丙氧基）丙基三甲氧基硅烷（KH560）和γ-甲基丙烯酰氧丙基三甲基硅烷（KH570）对纳米SiO₂表面改性,采用透射电子显微镜（TEM）、热失重分析仪（TGA）和冲蚀试验机考察了不同偶联剂的改性效果,包括对复合材料的形貌、耐冲蚀性和热稳定性的影响。结果发现,选择KH560对纳米SiO₂表面改性可获得最好的基体分散性和热稳定性。并采用KH550和KH560对TiB₂-Al₂O₃表面改性,利用扫描电子显微镜（SEM）和粒度分析仪比较了两种偶联剂的改性效果,选择KH560作为TiB₂-Al₂O₃的表面处理剂。其后,通过对凝胶时间的考察,研究了加入纳米粒子（SiO₂和Al₂O₃）后对固化工艺的影响。发现,第一,纳米粒子的加入可以减少固化剂用量,降低固化温度。第二,少量纳米粒子的加入会延缓固化反应速度,导致复合材料凝胶时间较纯树脂变长;而随着纳米粒子的含量增大,羟基增多,复合材料凝胶时间较纯树脂缩短,固化速度加快。第三,与纳米Al₂O₃相比,纳米SiO₂的反应活性更高,制备得到的复合材料凝胶时间更短。第四,探讨了偶联剂改性的反应机理。之后,采用粒径分析仪和TEM,观察了改性前后三种陶瓷粉体的水合粒子和两种纳米粒子在拼混树脂基体中的分散性。结果表明,改性后粒子的水合粒径较小,即表面改性改善了粒子在溶剂中的分散性。从改性前后的纳米Al₂O₃/拼混树脂复合材料TEM照片中可以看出,改性改善了粒子在树脂基体中的分散性。最后,研究了复合材料的各种力学性能和耐热性。从测试结果可知,改性后粒子对复合材料的弯曲性能起到增强作用。其中在相同粒子含量（3%）条件下,TiB₂-Al₂O₃粉体对于复合材料的弯曲性能增强效果最为明显。从正冲（90度）和斜角冲击（45度）考察了复合材料的耐冲蚀性能,发现纳米粒子的加入改善了复合材料的冲蚀性能,且纳米Al₂O₃在增强材料耐冲蚀性能方面胜过纳米SiO₂。TGA试验的结果也表明,改性纳米粒子的加入也改善了复合材料的热稳定性。更多还原

【Abstract】 Organic-inorganic hybrid composites combine both the advantages of organic polymer（lightweight,good impact resistance,flexibility and good process ability,etc.） and inorganic materials（high mechanical strength,good chemical resistance,thermal stability,etc.）.Thus,this kind of composites attracts more and more interests of scientists,and has been widely applied in various fields.In this study,three kinds of organic-inorganic hybrid composites were prepared, which included curing technology,nanosilica/resin composites,nanoalumina/resin composites and TiB₂-Al₂O₃/resin composites.They were studied in detail,including the preparation methods,mechanical and thermal properties.Meanwhile,the effects of surface modification on the structure and properties were studied.Firstly,Three kinds of coupling agents were used to modify the surface of the silica, and they were（γ-aminopropyl） triethoxysilane（KH550）,（γ-glycidoxypropyl） trimethoxysilane（KH560）,（γ-Methacryloxypropyl）trimethoxysilane（KH570）, respectively.Some characterization and analysis of the nanosilica treated by different kinds of coupling agents and the microstructure and heat resistant property of composites were performed by FTIR,Transmission electron micrograph（TEM）,TGA and erosion testing machine.The results showed that the nanosilica treated by KH560 got the best dispersion in the matrix and thermal stability.Secondly,influences of inorganic nano-fillers（silica and alumina） on curing process were studied by gel times.The results displayed that the fill of nano-particles reduced the amount of curing agent and curing temperature.Nano-particles can be reduced by adding the amount of curing agent,lower curing temperature.The gel times of resins containing few nano-fillers were longer than those of corresponding unfilled resin.With the increase of content of the nano-fillers,the hydroxy functional groups increase,and the gel times of composites were shorter than those of corresponding unfilled resin.Compared with nano-alumina,nanosilica has the higher reactivity and a shorter gel times.The mechanisms by which the inorganic fillers make the gel times of resin longer were studied.Thirdly,particle size analyzer and TEM were used to investigate the particle size dispersions of three inorganic particles（nanosilica,nano-alumina and TiB₂-Al₂O₃） and the dispersions of two nano-fillers in the resin matrix.The results displayed that after surface modification,hydration sizes of particles were smaller,that is,surface modification improved the dispersion of particles in the solvent.Seen from the TEM photographs of nano-alumina/resin composites and surface treated nano-alumina/resin composites,surface modification also improved the dispersion of particles in the resin matrix.At last,the mechanical properties and thermal properties were inspected.The bending test showed that after modification,nano-fillers played a strengthened role to composites.When the particle content was three percent,the enhancing effect of borides was best in the three fillers.The erosion resistance properties were tested,and the impact angles were 90 or 45 degrees.The result displayed that nano-fillers improved the erosion properties of resin,and nano-alumina showed erosion resistant properties better than nano-silica.TGA results showed that nano-fillers improved thermal stability of resin.更多还原