| 引用本文: | 安然,李柱,郭小平,刘栓,李想,王朴炎.石墨氮化碳复合环氧涂层的抗冲蚀性能[J].中国表面工程,2024,37(6):377~390 |
| AN Ran,LI Zhu,GUO Xiaoping,LIU Shuan,LI Xiang,WANG Puyan.Erosion Resistance of Graphite Nitride Carbon Composite Epoxy Coating[J].China Surface Engineering,2024,37(6):377~390 |
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| 摘要: |
| 海工装备暴露在腐蚀最为严重的浪花飞溅区，会遭受力学-化学 / 电化学腐蚀的耦合损伤，造成严重的金属腐蚀。涂装抗冲蚀涂层是减缓海工装备冲蚀磨损的重要手段。石墨氮化碳（g-C3N4）不仅具有良好的化学稳定性和力学性能，还具有类石墨烯的二维层状结构，可作为功能填料来提高有机涂层的综合防护性能。但 g-C3N4 易团聚，直接与环氧树脂复合会产生缺陷，导致涂层快速失效。采用磺化聚苯胺（SPANi）对 g-C3N4改性得到 g-C3N4@SPANi，并与厚朴酚基四官能环氧树脂（MTEP） 结合制备防腐和抗冲蚀涂料。采用拉伸应力应变、电化学阻抗和固 / 液 / 气三相流冲蚀机对环氧复合涂料的力学性能、防腐性能和抗冲蚀防护性能进行表征，发现在纯 MTEP 中添加 0.5wt.% g-C3N4@SPANi，其拉伸强度和断裂应变为 48.3 MPa 和 8.75%，分别比纯 MTEP 提高 68.8%和 19.05%，抗冲蚀试验后环氧复合涂层的质量损失和体积损失分别比纯 MTEP 降低了 68.41%和 66.39%，在 3.5wt.% NaCl 溶液浸泡 60 d 后环氧复合涂层低频阻抗模值为 3.25 GΩ·cm2 ，比纯 MTEP 低频阻抗模值 0.112 MΩ·cm2 提高四个数量级。环氧复合涂层防腐和抗冲蚀性能的提升，主要归功于 SPANi 在 g-C3N4 表面的接枝增加了 g-C3N4 表面粗糙度，同时 g-C3N4@SPANi 与环氧树脂兼容性好，提高了涂层的致密性和韧性，进而提高复合涂层的抗冲蚀性能。因此，通过利用 SPANi 对 g-C3N4 化学改性，能有效降低水分子向环氧涂层内部的渗透速率，为新型功能填料在环氧涂层中的应用提供新思路。 |
| 关键词: 石墨氮化碳 磺化聚苯胺 厚朴酚基四官能环氧树脂 涂层 冲蚀 |
| DOI：10.11933/j.issn.1007-9289.20240325001 |
| 分类号:TB332；TQ638 |
| 基金项目:国家重点研发计划项目（2023YFC2809901）；宁波市电力设计院有限公司科技项目（KJXM2022053）；大型火电厂烟气余热深度利用自洁板式换热器研发及工程应用（ZB23YQOFG037F） |
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| Erosion Resistance of Graphite Nitride Carbon Composite Epoxy Coating |
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AN Ran1，2，LI Zhu2，GUO Xiaoping2，LIU Shuan2，LI Xiang3，WANG Puyan4
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1.School of Chemistry and Chemical Engineering, Jiangxi University of Science and Technology,Ganzhou 341000 , China ；2.Key Laboratory of Advanced Marine Materials, Ningbo Institute of Materials Technology and Engineering,Chinese Academy of Sciences, Ningbo 315201 , China ；3.Zhejiang Baimahu Laboratory Co., Ltd., Hangzhou 311121 , China ；4.Ningbo Electric Power Design Institute Co., Ltd., Ningbo 315000 , China
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| Abstract: |
| As inland resources continue to be depleted, the exploration and exploitation of marine resources have expanded. However, the marine engineering equipment used in this process, including ships and deep-sea probes, undergoes corrosion, owing to the complex marine environment. Additionally, in the splash zone, the impact of seawater, oxygen, and hard solid particles causes erosion wear and chemical / electrochemical corrosion on metal equipment, which significantly reduces the service life of marine engineering equipment in marine environments. Protective coatings are applied to counteract the impact damage to marine engineering equipment. However, epoxy coatings, owing to their high cross-linking density and brittleness, are prone to delamination and failure upon impact with seawater. The curing process also generates significant shrinkage, which allows water to penetrate the coating and contact the metal substrate, thereby leading to corrosion. Therefore, enhancing the interfacial bonding strengths of epoxy coatings by incorporating functional fillers can effectively resist the adverse effects of seawater impact. Graphitic carbon nitride (g-C3N4) exhibits excellent chemical stability and mechanical properties, and its two-dimensional graphene-like layered structure effectively blocks seawater. Functionalizing g-C3N4 to improve its dispersibility and corrosion protection is beneficial. In this study, in situ polymerization was employed to graft and dope g-C3N4 surfaces with p-aminobenzenesulfonic acid (ASA) modified polyaniline (PANi) nanofibers, thereby resulting in a g-C3N4@SPANi composite functional filler. This filler was combined with a magnolia phenolic tetrafunctional epoxy resin (MTEP) to prepare anti-corrosion and anti-erosion coatings. The phase and structure of the fillers were analyzed using X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The microstructure of the fillers was examined using transmission electron microscopy, and the cross-sectional morphology of the coatings was assessed using cold field emission scanning electron microscopy. The mechanical properties, corrosion resistance, and impact protection performance of the epoxy composite coatings were characterized using tensile stress-strain, electrochemical impedance, and solid / liquid / gas triphase flow erosion tests. The results showed that adding 0.5wt.% g-C3N4@SPANi to pure MTEP increased the tensile strength and elongation to 48.3 MPa and 8.75%, respectively, constituting improvements of 68.8% and 19.05% over those of pure MTEP. After soaking in a 3.5wt.% NaCl solution for 60 days, the low-frequency impedance modulus of the epoxy composite coating was 3.25 GΩ·cm2 , which is four orders of magnitude higher than that of pure MTEP at 0.112 MΩ·cm2 . The results of an analysis of the corrosion potential (Ecorr) and self-corrosion current (icorr) through dynamic potential polarization curves revealed significant increases in Ecorr and reductions in icorr in the MTEP coating after the addition of 0.5wt.% g-C3N4@SPANi, thereby demonstrating excellent corrosion resistance. Erosion tests showed that the addition of 0.5wt.% g-C3N4@SPANi reduced the mass and volume losses of the MTEP coating by 68.41% and 66.39%, respectively, while significantly reducing the depths of erosion pits. This enhancement in the anti-corrosion and anti-erosion performance of the MTEP coating is primarily because of the increase in the roughness of g-C3N4that is caused by the grafting of sulfonated polyaniline, which also improves the compatibility of g-C3N4@SPANi with the epoxy resin, thereby enhancing the density and toughness of the coating as well as improving the impact resistance of the composite coating. This study proposes a novel modification method for graphitic carbon nitride (g-C3N4) using sulfonated polyaniline (SPANi) for surface modification, resulting in the production of a g-C3N4@SPANi composite functional filler. This modification method enhances the roughness of g-C3N4 by introducing sulfonic groups, thereby strengthening the interfacial bond with the epoxy resin. Therefore, chemically modifying graphitic carbon nitride with sulfonated polyaniline can effectively enhance the interface compatibility of g-C3N4 and enable it to be better dispersed in MTEP to thereby reduce the penetration rate of water molecules into MTEP coatings, improve the erosion resistance of MTEP coatings, and provide new insights for the application of novel functional fillers in epoxy coatings. |
| Key words: graphitic carbon nitride sulfonated polyaniline magnolol-based tetrafunctional epoxy resin coating erosion |
