基于东北地区环境下复合水性防腐涂料的制备及性能

Preparation and properties of water-based composite anticorrosive coatings based on the environment in the Northeast China

摘要:

为应对东北地区的气温骤变和丰富降水易对金属设备造成的腐蚀问题，提升水性丙烯酸树脂（AP）中掺杂氧化石墨烯（GO）分散性和对金属的腐蚀防护能力，以六亚甲基二异氰酸酯（Tri-HDI)）、对苯二胺、聚乙烯吡咯烷酮（PVP）与3-氨丙基三乙氧基硅烷（APTES）对GO进行改性，提高GO的分散性、层间距和强度，得到强化分散型氧化石墨烯（Reinforced Dispersion Graphene Oxide，RDGO），最后利用湿式转移法将RDGO和AP复合，制备水性防腐涂料RDGO/AP。采用FTIR、Raman、XRD、SEM表征和TGA测试以及电化学和腐蚀实验，考察RDGO/AP涂层的物理特性和防腐蚀能力。结果表明，GO引入了新的C—N基团，RDGO呈二维晶体结构，层间距从GO的0.0761 nm扩大至0.1045 nm，避免了GO的团聚现象；RDGO的失重起点温度为259.16 ℃，具有良好的热稳定性。与AP涂层相比，RDGO/AP涂层水接触角（98°）增大了4°，硬度（4H）提升了2H，附着力（1级）提升了2级；经过在3.5%的NaCl溶液中浸泡14 d的腐蚀实验后，与AP涂层相比，RDGO/AP涂层的腐蚀电压提高了0.479 V，腐蚀电流密度降低了1.172×10-5 A/cm2，保护效率高达99.90%。RDGO/AP具有良好的防腐蚀能力的原因在于，RDGO与AP结合后，其表面的羰基基团易与AP中的氢原子发生接枝效应，提高了RDGO在丙烯酸树脂体系中的分散性，增强了界面的粘结力，提高了涂层的韧性和剪切强度，加了大RDGO与成膜基底的结合力，提升了涂层防腐效果。

Abstract:

To cope with the corrosion problem of metal equipment caused by sudden temperature changes and abundant precipitation in the Northeast region of China and to improve the dispersibility and corrosion protection ability of graphene oxide (GO) doped in waterborne acrylic resin (AP), GO was modified using hexamethylene diisocyanate (Tri-HDI), p-phenylenediamine, polyethylene pyrrolidone (PVP) and 3-aminopropyltriethoxysilane (APTES) to improve the dispersibility, layer spacing and strength of GO, and obtain reinforced dispersion graphene oxide (RDGO). Finally, RDGO and AP were combined using wet transfer method to prepare waterborne anti-corrosion coating RDGO/AP. The physical properties and corrosion resistance of RDGO/AP coating were investigated using FTIR, Raman, XRD, SEM characterization, TGA testing, as well as electrochemical and corrosion experiments. The results showed that GO introduced new C—N groups and RDGO exhibited a two-dimensional crystal structure. The interlayer spacing was increased from 0.0761 nm to 0.1045 nm, and thus the aggregation phenomenon of GO was avoided. The starting temperature for weight loss of RDGO was 259.16 ℃ and RDGO had good thermal stability. Compared with AP coating, the water contact angle (98°) of RDGO/AP coating increased by 4°, the hardness (4H) increased by 2H, and the adhesion (level 1) increased by 2 levels. After soaking in a 3.5% NaCl solution for 14 days, the corrosion voltage of RDGO/AP coating increased by 0.479 V and the corrosion current density decreased by 1.172×10-5 A/cm2 compared with AP coating. The protection efficiency of RDGO/AP coating was up to 99.90%. The reason why RDGO/AP had good corrosion resistance was that after binding with AP, carbonyl groups on the surface of RDGO were prone to grafting with the hydrogen atoms in AP, improving the dispersibility of RDGO in the acrylic resin, strengthening the interfacial adhesion, increasing the toughness and shear strength of the coating, and elevating the adhesion between RDGO and the film-forming substrate, thereby enhancing the anti-corrosion effect of the coating.