氯离子触发的有机无机复合壁材微胶囊的制备及性能研究

发布时间：2018-01-08 00:03

  本文关键词：氯离子触发的有机无机复合壁材微胶囊的制备及性能研究　出处：《深圳大学》2015年硕士论文　论文类型：学位论文

  更多相关文章： 化学触发 自修复混凝土 复合壁材微胶囊 氯离子

【摘要】：氯离子是引起混凝土中钢筋锈蚀的主因。如果采用氯离子敏感微胶囊将氯离子吸收剂、钢筋阻锈剂或者修复剂预埋在混凝土中,就可以减缓氯离子在混凝土中的渗透,阻断其到达钢筋表面的扩散途径,提高了这些工程在高盐环境下的耐久性,产生巨大的经济效益和社会效益。本文设计和制备了氯离子触发离子的微胶囊。该微胶囊的壁材为嵌有不溶性金属无机盐颗粒的憎水性聚合物。在无氯水中,该微胶囊很稳定。在含氯离子的水中,囊壁上无机盐的金属离子因与氯离子络合,生成可溶性络合离子而离去,在囊壁上留下细孔,使水渗入,芯材溶胀而使微胶囊破裂,实现化学触发功能。选用硫酸铅和氯化亚铜为触发源,采用溶剂蒸发法,分别制备了以十六烷为芯材,嵌有硫酸铅的聚甲基丙烯酸甲酯为壁材的微胶囊(Hexadecane/Pb SO4-PMMA),和以环氧树脂E-51为芯材,嵌有氯化亚铜的聚苯乙烯为壁材的微胶囊(E-51/Cu Cl-PS)。研究了芯壁比、搅拌速率、乳化剂种类与浓度等对胶囊性能的影响,优化了这两种复合壁材微胶囊的制备工艺。利用光学显微镜(OM)、扫描电子显微镜(SEM)、傅里叶红外(FTIR)、差热分析仪(DSC)、热重分析仪(TGA)和X射线衍射(XRD)对微胶囊的形貌和结构进行了表征。结果表明,在制备过程中,原料配比、蒸发温度、搅拌速率、表面活性剂种类及用量等对微胶囊的形貌和结构都有很大的影响,其中乳化剂的种类和用量、搅拌速率,主要影响了微胶囊囊壁上金属无机盐颗粒的粒径大小、嵌入量分布和分布。实验优化了微胶囊的制备工艺,当芯壁比为1.5:1~1:1,搅拌速率为400rpm左右,表面活性剂为PVA,浓度为5%,蒸发温度为40℃,蒸发时间为2~3h时,获得微胶囊性能较佳。在该工艺条件下,金属无机盐颗粒在壁材中分散液很均匀,制得的微胶囊的平均粒径为150μm,且分布较窄。纳米压痕仪测得,Hexadecane/Pb SO4-PMMA微胶囊壁材的弹性模量为2.504Gpa,硬度为0.036Gpa;E-51/Cu Cl-PS微胶囊壁材的弹性模量为2.01Gpa,硬度为0.029 GPa。在模拟海水中的触发试验表明,Hexadecane/Pb SO4-PMMA微胶囊和E-51/Cu Cl-PS微胶囊壁在水溶液中对氯离子均有很好的响应,响应时间分别为5小时和1小时。若氯盐浓度增加,则响应时间缩短。
[Abstract]:Chloride ion is the main cause of corrosion of steel bars in concrete. If chloride ion sensitive microcapsules are used to pre-bury chloride ion absorbent, corrosion inhibitor or repair agent in concrete. It can slow down the penetration of chloride ions in concrete, block the diffusion of chloride ions to the surface of steel bar, and improve the durability of these projects in high salt environment. In this paper, we designed and prepared the microcapsule which is triggered by chloride ion. The wall material of the microcapsule is hydrophobic polymer with insoluble metal inorganic salt particles. The microcapsule is very stable. In the water containing chloride ions, inorganic salt metal ions in the capsule wall are complexed with chloride ions to form soluble complex ions, leaving fine pores in the wall of the capsule to make water permeate. When the core material was swelled, the microcapsule was broken and the chemical trigger function was realized. Using lead sulfate and cuprous chloride as trigger source, hexadecane as core material was prepared by solvent evaporation method. Hexadecane / Pb SO4-PMMAA and epoxy resin E-51 were used as core materials for microencapsulation of polymethyl methacrylate with lead sulfate as wall material. The effects of core wall ratio, stirring rate, type and concentration of emulsifier on the properties of the microcapsules were studied. The preparation process of these two kinds of composite wall microcapsules was optimized by optical microscope, scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR) and differential thermal analyzer (DSCS). The morphology and structure of microcapsules were characterized by thermogravimetric analysis (TGA) and X-ray diffraction (XRD). The types and dosage of surfactants have a great influence on the morphology and structure of microcapsules. The type and dosage of emulsifiers and stirring rate mainly affect the particle size of metal inorganic salt particles on the wall of microcapsules. The preparation process of microcapsules was optimized. When the core / wall ratio was 1.5: 1: 1: 1, the stirring rate was about 400rpm, the surfactant was PVA and the concentration was 5%. When the evaporation temperature is 40 鈩，

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