基于二氧化硅与机制砂的复合材料的制备及其性能研究

发布时间：2018-01-27 04:49

本文关键词： 二氧化硅机制砂润滑油添加剂净浆砂浆　出处：《合肥工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：鉴于纳米SiO2易于工业化生产,具有较好的耐热性、耐压性等特性,更适合应用于铁路、高速公路、桥梁等建筑领域。然而,纳米SiO2比表面积大、表面能极高,易于发生微粒之间的团聚,难以与基料很好结合,导致材料性能下降,影响纳米SiO2微粒所具有的功能得到应有的发挥。因此,本文通过纳米SiO2表面改性合成复合材料,提高纳米SiO2的分散性,减少团聚,有效的解决上述难题。水泥基复合材料以硅酸盐水泥为基体构成的复合材料,广泛应用于房屋、铁路、公路、桥梁等建筑领域。机制砂是一种理想的细骨料,但是机制砂颗粒粗糙,这势必减弱水泥基复合材料的流动性,增加需水量。因此,本文通过高亲水聚合物改性水泥基复合材料,减弱机制砂对水泥基复合材料的流动性影响,提高机制砂的分散性、减少团聚。主要工作内容如下：(1)利用丙烯酸和MPEG(2.甲基丙烯酸聚乙二醇单甲醚酯)高分子化合物修饰机制砂(AS)制备一种新型复合材料,合成的复合材料能有效的改善机制砂石粉在水泥中的和易性,同时提供一种以化学接枝代替传统的物理吸附的理论思路。首先利用硅烷偶联剂γ-(甲基丙烯酰氧)丙基三甲氧基硅烷(MPS)与机制砂石粉表面羟基反应,使机制砂石粉表面带有C=C化学官能团,然后与丙烯酸(AA)、MPEG高分子化合物共聚,生成的高分子化合物以化学键的方式链接在机制砂的表面。采用傅里叶变换红外光谱(FI-IR)、场发射扫描电镜、热重、X射线衍射手段表征了机制砂石粉的改性效果和结构。将合成的复合材料以不同的比例掺杂于水泥中,在净浆实验中研究合成材料与水泥的流动适应性和保持性。净浆实验表明,修饰后的机制砂石粉相比未修饰的机制砂石粉的可流动性及其保持性有较大改善,高分子化合物改性后的机制砂石粉于水泥中的流动适应性和保持性有显著的提高,该思路合成的新型材料对水泥基复合材料的理论研究有一定的现实意义。(2)超细二氧化硅由于其优良的摩擦学性能,在润滑油添加剂领域倍受关注。本文介绍了超细二氧化硅的表面结构特征、表面改性机理及常用的改性方法,着重介绍了醇酯法、硅烷偶联剂法及表面聚合物接枝改性法,并对其改性趋势作了进一步探究。最后概述了超细二氧化硅在润滑油中的应用,并展望了其在润滑油中的应用发展趋势。
[Abstract]:Because nanometer SiO2 is easy to industrialize and has good heat resistance, pressure resistance and so on, it is more suitable for application in railway, highway, bridge and other construction fields. However, nanometer SiO2 has a large specific surface area. The surface energy is very high and it is easy to reunite between particles, which makes it difficult to combine well with the base material, which leads to the deterioration of material properties, which affects the function of SiO2 nanoparticles to be played. In order to improve the dispersity and reduce the agglomeration of nano SiO2, the surface modification of nano SiO2 was used to synthesize the composite. Cement matrix composite composed of Portland cement is widely used in building, railway, highway, bridge and other construction fields. The machine-made sand is an ideal fine aggregate. However, the mechanism sand particles are rough, which will weaken the fluidity of cement matrix composites and increase water demand. Therefore, the high hydrophilic polymer is used to modify the cement matrix composites in this paper. The influence of machine-made sand on the fluidity of cement-based composites is weakened, and the dispersion of machine-made sand is improved. Reducing agglomeration. The main work is as follows: 1) A new composite material was prepared by using acrylic acid and MPEGG 2. Methacrylic acid poly (ethylene glycol monomethyl ether ester) modified macromolecule compound (ASA). The composite material can effectively improve the properties of machine-made sand and stone powder in cement. At the same time, it provides a theoretical idea of chemical grafting instead of traditional physical adsorption. Firstly, the silane coupling agent 纬-(methacrylol) propyl trimethoxy silane (MPS) is used. Reaction with hydroxyl group on the surface of machine-made sand and stone powder. The surface of the mechnical sand powder was made with Con C chemical functional group, and then copolymerized with acrylic acid (AA) and MPEG macromolecule compound. The resulting polymer compounds were linked to the surface of the machine-made sand by chemical bonds. Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (SEM) and thermogravimetry (TGA) were used. The modified effect and structure of the machine-made sand powder were characterized by X-ray diffraction. The synthesized composites were doped into cement in different proportions. The fluidity and maintainability of synthetic materials and cement were studied in the slurry experiment. The results showed that the fluidity and retention of modified machine-made sand and stone powder were much better than that of unmodified machine-made sand and stone powder. The flow adaptability and maintainability of the machine-made sand and stone powder modified by polymer compounds in cement were improved significantly. The new material synthesized by this method has a certain practical significance for the theoretical study of cement matrix composites. The ultrafine silicon dioxide has excellent tribological properties due to its excellent tribological properties. In this paper, the surface structure characteristics, surface modification mechanism and common modification methods of ultrafine silica are introduced, with emphasis on alcohol-ester method. The methods of silane coupling agent and surface polymer grafting modification were further explored. Finally, the application of ultrafine silica in lubricating oil was summarized. The development trend of its application in lubricating oil is prospected.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB332;TE624.82

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