无铬达克罗涂料中锌铝粉析氢规律的研究

发布时间：2018-02-03 07:43

  本文关键词： 锌铝粉 析氢规律 吐温80 烟酸 KH560　出处：《沈阳工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：达克罗是指由片状锌粉、片状铝粉、分散剂、铬酐和其它助剂等组成的新型防腐涂料,在金属腐蚀的防护方面发挥着重要的作用。但达克罗涂料中存在的Cr~(6+)具有高毒性和高致癌性,对自然环境造成巨大污染,是人类健康的巨大威胁。因此,无铬达克罗技术应运而生。由于失去了Cr~(6+)的钝化作用,锌铝粉在无铬达克罗涂料中出现严重的析氢现象,导致涂料储存时间明显缩短,涂层性能显著降低,这使无铬达克罗涂料的应用受到极大限制。为解决这一问题,本文以无铬达克罗涂料中的片状锌铝粉为研究对象,在无铬水性环境中,对锌铝粉的析氢规律进行了研究。旨在全面深入地认识无铬达克罗中片状锌铝粉的析氢规律,为新型环保无铬达克罗涂料的研制奠定基础。本文确定了以10mass%吐温80水溶液为腐蚀介质。研究了不同比例的锌铝粉(包括纯锌粉、锌铝9:1、8:2、7:3、6:4、5:5、4:6、3:7、2:8、1:9混粉、纯铝粉)在水性环境中的析氢腐蚀规律。同时,改变水浴温度分别为40℃、45℃、50℃,研究温度对各比例锌铝粉析氢腐蚀的影响。在腐蚀介质中加入烟酸,研究了烟酸作为钝化剂对不同比例锌铝粉(包括纯锌粉、锌铝8:2、6:4、4:6、2:8混粉、纯铝粉)析氢腐蚀的影响。通过改变烟酸含量(分别取1g/L、2g/L、3g/L),研究烟酸含量对烟酸抑制作用的影响。将水浴温度依次设置为40℃、45℃、50℃,研究温度变化对烟酸抑制作用的影响。在腐蚀介质中加入硅烷偶联剂KH560,研究了KH560对不同比例锌铝粉(包括纯锌粉、锌铝8:2、2:8混粉、纯铝粉)析氢腐蚀的影响。将水浴温度依次设置为40℃、45℃、50℃,研究温度变化对KH560抑制作用的影响。在腐蚀介质中同时加入烟酸和KH560,研究KH560和烟酸复配在不同温度下对锌铝粉析氢腐蚀的影响。结果表明,锌粉的析氢量最小,随着铝粉比例的增大,析氢量在不断递增,铝粉的析氢量最大。环境温度越高,析氢速度越大,析氢量也越大。烟酸在控制锌铝粉的析氢量和抑制析氢速度方面是一个效果很好的钝化剂,烟酸的含量越高,抑制效果越明显,当烟酸含量为3g/L时,即可发挥较为满意的抑制效果。另外,烟酸对锌铝粉析氢腐蚀的抑制效率随温度升高而不断降低。硅烷偶联剂KH560仅在反应前期能够抑制锌铝粉的析氢腐蚀,延长了析氢诱导阶段的时间。在反应中后期却增大了锌铝粉的析氢量。KH560与烟酸复配对锌铝粉析氢腐蚀的抑制效果远不及烟酸单独加入。
[Abstract]:Dacromet is a new anticorrosive coating composed of flake zinc powder, flake aluminum powder, dispersant, chromic anhydride and other additives. It plays an important role in the protection of metal corrosion, but the existence of Cr~(6 in Dacromet paint has high toxicity and carcinogenicity, which causes huge pollution to the natural environment. It is a great threat to human health. Therefore, chromium-free Dacromet technology emerged as the times require. Due to the loss of Cr~(6) passivation, zinc and aluminum powder in chromium-free Dacromet paint appear serious hydrogen evolution phenomenon. In order to solve this problem, the storage time and the properties of coatings are obviously shortened, which greatly limits the application of chromium-free Dacromet coatings. In this paper, the flake zinc-aluminum powder in chromium-free Dacromet coating was used as the research object, in the chromium-free water environment. The rule of hydrogen evolution of zinc-aluminum powder was studied in order to fully and deeply understand the rule of hydrogen evolution of zinc-aluminum powder without chromium-free Dacromet. In this paper, 10wt% Tween 80 aqueous solution was used as the corrosion medium. Different proportions of zinc and aluminum powder (including pure zinc powder and zinc aluminum 9: 1) were studied. At 8: 2, 7: 3, 6: 4, 5: 5, 6: 6, 3: 7, 7: 7, 2: 8, 8: 1: 9, pure aluminum powder, hydrogen evolution corrosion in aqueous environment. At the same time, changing the water bath temperature to 40 鈩，

本文编号：1486822