【作者】 金辉；

【导师】 张爱玲；

【作者基本信息】 沈阳工业大学 ， 材料物理与化学， 2007， 硕士

【摘要】 由于国际上已公认石棉是一种致癌物质,许多国家已逐步禁止石棉制品的生产和使用,但目前尚无一种能完全代替石棉的橡胶增强材料,因此寻找替代石棉材料已成为现代密封材料领域的一个重要研究方向。芳纶纤维由于具有高强度、高模量等优异性能,成为代替石棉的首选材料。但由于芳纶纤维表面光滑、无反应活性,导致与大多数基体之间的界面粘附性较差,影响复合材料力学性能的发挥,因此需要对芳纶表面进行改性处理。本文采用国产间位芳纶纤维作为代替石棉的增强材料,突破现有的芳纶改性方法,采用界面聚合法将芳纶纤维表面改性后与丁腈橡胶复合,制备成芳纶增强橡胶密封复合材料,并对材料的结构、性能、复合机理进行了研究。创新之处在于,改性后的芳纶形态为毛棒状,且具有液晶性能。采用NaOH/乙醇溶液对间位芳纶进行水解处理,使纤维表面水解生成活性-NH₂基团。利用界面聚合法,使水解后的芳纶纤维与介晶单体DDBA,液晶离聚物BY,癸二酰氯等发生接枝反应,分别制得DDBA改性芳纶纤维和DDBA、BY改性芳纶纤维。通过SEM、FTIR、DSC、POM等对改性前后芳纶的结构和性能进行了表征,结果表明,芳纶纤维经水解处理后,表面生成活性-NH₂,可以引发界面聚合反应的发生,实现芳纶的表面接枝;改性后的芳纶纤维,表面生成接枝聚合物,表面粗糙度明显增加,且具有液晶性能。将芳纶纤维与丁腈橡胶制备成芳纶纤维增强橡胶密封复合材料后,对材料的各项性能进行了测试,结果表明改性芳纶增强橡胶密封复合材料的各项性能均达到标准的要求,且均优于芳纶原料增强橡胶复合材料。研究了芳纶纤维的改性机理及芳纶纤维/橡胶界面复合理论,认为界面复合以机械互锁作用为主。更多还原

【Abstract】 Asbestos is a kind of cancerogen accepted internationally, so many countries are gradually forbidding the production and use of the asbestos products. But now, there is not a kind of rubber reinforced material which can take place of asbestos completely. Therefore, looking for the materials which replace asbestos becomes an important research direction in modern sealing material area. Aramid fiber is of the high strength and modulus and other excellent properties, so it becomes the preferred material to replace asbestos. Because aramid fiber’s surface is smoothing and lack of reactive activity, it is difficult to adhere to many kinds of matrixes, which affects the mechanics of composites. Thus the surface modification of aramid fiber is needed.In this paper, the domestic meta-aramid fiber as the material replacing asbestos and the method of interfacial polymerization are been used to complete the aramid’s surface modification. Combining with NBR, the composite material reinforced with aramid fiber have been synthesized. The structure, properties and mechanism are also been studied. It is novel that the morphology of modified aramid fibers is rigid-rod and the fiber has liquid crystalline properties.In the experiment, the -NH2 groups are introduced to the surface of meta-aramid fibers by treating the fiber surface with dilute sodium hydroxide solution. The modified aramid fibers which are grafted separately by DDBA, DDBA and BY are synthesized by interfacial polymerization of the DDBA, BY, sebacoyl dichloride and aramid fibers hydrolysed. The structure and properties of aramid fibers before and after modification are characterized by SEM, FTIR, DSC and POM. The results show that after hydrolyzing, the -NH2 groups are introduced to the surface of aramid, which can initiate interfacial polymerization to realize the modification of aramid; the surface of grafted aramid is very rough, and the modified fiber has liquid crystalline properties.Combining the aramid fiber with NBR, the composite material reinforced with aramid fiber has been synthesized. The properties of the material have been testing. The results show that the properties of the modified aramid/NBR composite material, which is superior to the raw aramid/NBR composite material, can meet the standard requirements. The mechanism of modification and adhesion are also been researched, and it is considered that mechanical interlocking is the main mechanism on the composite interface.更多还原