碳钢表面石墨烯基水性纳米复合涂层的制备及其腐蚀防护机理

Corrosion of carbon steel is easy to occur and causes huge losses to national economy. It is of great significance to conduct the study of corrosion protection methods for carbon steel. Protective coatings made of graphene or its composite materials for the metal not only significantly slow down the corrosion rate of metals, but also have more excellent mechanical properties and high strength compared with the traditional polymer coating. However, it is difficult to realize the industrialization of graphene coating for metals due to the tough preparation conditions and high cost. In this project, a polymer surfactant aided electrochemical approach was employed to produce aqueous dispersion of graphene. Aqueous solutions of polymer surfactant rich in styrene unit are used as electrolyte and aqueous dispersions of polymer-functionalized graphene are obtained by electrochemical intercalation/exfoliation of graphite via the π-π interaction between the styrene unit of polymer surfactant and π orbital of graphene. Graphene/organic composite water-based resin is obtained by solution blending or in situ polymerization method. Simple preparation of water-based nanocomposite coating based on graphene on carbon steel surface is realized by combination of graphene/organic composite water-based resin and corrosion inhibitor. Formation mechanism and synergistic corrosion resistant mechanism of water-based nanocomposite coating based on graphene are discussed and the results obtained would provide a new preparation approach and basic theory for developing a valuable and applicable anti-corrosion coating material for carbon steel surface.

碳钢易腐蚀，给国民经济造成巨大的损失，研究碳钢的腐蚀防护方法，具有十分重要的意义。石墨烯及其复合材料作为金属表面防护涂层不仅显著延缓金属的腐蚀速度，相比于传统的聚合物涂层，更具有优良的机械性能和很高的强度，但因其制备条件苛刻、成本高，难以实现工业化应用。本项目采用高分子表面活性剂辅助电化学法制备石墨烯水分散液，以富含苯乙烯单元的高分子表面活性剂水溶液为电解液，利用苯乙烯单元与石墨烯的π轨道之间的π-π相互作用，通过电化学法实现高分子对石墨的插层、剥离, 从而获得高分子功能化石墨烯水分散液；通过溶液共混或原位聚合方法制备石墨烯/有机复合水性树脂，将其与缓蚀剂复配，实现碳钢表面石墨烯基水性纳米复合涂层的简单制备；探讨石墨烯基水性纳米复合涂层的形成机理及协同耐蚀机理，为发展具有应用价值的碳钢表面防腐涂层材料提供新颖制备途径与基础理论依据。

为实现碳钢表面石墨烯基水性纳米复合防腐涂层的简单制备，本项目通过高分子辅助电化学法实现石墨烯水分散液高效、低成本的制备，采用溶液共混或原位聚合方法制备石墨烯复合涂层材料并作用于碳钢表面，探讨了石墨烯复合涂层的形成机理及协同耐蚀机理。主要研究结果如下：（1）以富含苯乙烯单元的水解苯乙烯-马来酸酐共聚物水溶液为电解液，石墨为电极，通过电化学法实现石墨烯片层的剥离和功能化，获得稳定的水解苯乙烯-马来酸酐共聚物功能化石墨烯水分散液。采用溶液共混法将其与水溶性有机硅改性树脂和缓蚀剂复配并作用于碳钢表面，复合涂层中均匀分布的功能化石墨烯与缓蚀剂通过协同作用显著提高了复合涂层的耐蚀性能；（2）采用原位化学氧化聚合方法制备出稳定的水解苯乙烯-马来酸酐共聚物功能化石墨烯/聚吡咯和水解苯乙烯-马来酸酐共聚物功能化石墨烯/聚苯胺复合材料水分散液，将其分别与水性有机硅氧烷改性树脂和聚氨酯复合，通过溶液共混法作用于碳钢表面形成复合涂层，能够有效提高涂层的耐蚀能力；（3）以天然高分子腐殖酸水溶液为电解液，石墨纸为阳极，在电解过程中实现石墨烯片层的剥离和功能化，获得稳定的腐殖酸功能化石墨烯，将其添加到聚氨酯涂层中，石墨烯优异的阻隔性能有效提高了复合涂层对碳钢的腐蚀防护；（4）通过分子设计合成出一种有机硅氧烷丙烯酸酯单体，采用半连续无皂乳液聚合方法制备了富含氨基和硅羟基的自交联有机硅氧烷改性丙烯酸酯乳液，将其与腐殖酸功能化石墨烯复合并作用于碳钢表面，能形成自修复防腐涂层。在项目执行期间，已发表论文5篇（SCI论文2篇，CSCD论文3篇），待发表3篇。申请国家发明专利2项。培养硕士研究生4名，其中3名已取得硕士学位，1名在读。本项目获得了高分子功能化石墨烯水分散液的高效制备技术，探讨了碳钢表面石墨烯基水性纳米复合涂层的形成机理和协同耐蚀机理，为发展具有应用价值的碳钢表面水性防腐涂层材料提供新颖制备途径与基础理论依据。