适用于深海压力-流体耦合环境的玄武岩有机防腐涂层的制备及性能研究

Preparation and Anticorrosive Performance of a Basalt Organic Coating for Deep Sea Coupled Pressure-fluid Environment

片状阻挡型无机填料可显著延长腐蚀介质在有机涂层中的扩散路径,被广泛应用于海洋防腐涂层领域。然而,在深海环境压力-流体耦合作用下,涂层中填料/树脂界面薄弱处往往因应力集中而导致涂层开裂。针对该问题,本工作选取玄武岩鳞片作为实验对象,根据其结构特性采用化学刻蚀方法在鳞片表面形成微结构;随后利用硅烷偶联剂改性玄武岩鳞片,降低了填料的表面能。通过以上处理可明显改善填料在有机树脂中的润湿性,增强了填料与树脂的界面结合能力。涂层失效行为结果表明,刻蚀-改性后玄武岩与树脂相容性好,偶联剂分子又参与涂层固化而进一步增加了涂层与填料间的界面结合力。实验进行240 h后,改性玄武岩环氧(EMB/E)涂层的阻抗模值(|Z|_(0.01 Hz))比未改性玄武岩(B/E)涂层的高一个数量级。玄武岩有机防腐涂层有效降低了压力-流体耦合环境对填料/涂层界面的劣化作用,在深海环境中可表现出更好的防护性能。

Sheet-like blocking inorganic fillers are widely used in the marine anti-corrosion coating field as their high aspect ratios significantly extend the diffusion path of the corrosive medium in organic coatings.However,under the coupling action of pressure-flow of seawater in the deep sea,the weak point at the filler/resin interface in the coating often cracks due to stress concentration.To address this issue,the purpose of this article is to study the feasibility of application of the modified basalt flakes,as a filler material,to enhance the adhesion of the filler/resin interface of organic coatings.Basalt flakes were firstly chemically etched to endow with peculiar surface morphology,which afterwards were modified with a silane coupling agent to reduce their surface energy.As a result,the wettability of the modified basalt flakes to the organic resin and the interfacial bonding between the modified basalt flakes and the resin are all significantly enhanced.The failure behavior of the coating under the coupling action of pressure-flow of seawater in a simulated deep sea condition showed that the etched-modified basalt filler had a good compatibility with the resin,and the surface coupling agent molecules could participate in the curing of the coating and further increase the interfacial bonding between the coating and the filler.After corrosion test in artificial seawater by couplingaction of pressure-flow conditions for 240 h,the impedance modulus(|Z|_(0.01 Hz))of the etched-modified basalt epoxy(EMB/E)coating was one order of magnitude higher than that of the unmodified basalt(B/E)coating.Therefore,the basalt organic coating effectively reduces the deterioration of the filler/coating interface under the coupling action of pressure-flow of seawater in simulated deep sea conditions.It can be expected to select the epoxy coating with modified basalt flakes as a candidate coating of better protective performance for engineering application in deep-sea environments.