Expired drugs as vapor-phase corrosion inhibitors of copper in simulated marine atmospheric environment

模拟海洋大气环境中过期药品气相缓蚀剂对紫铜的缓蚀作用

Urea,paracetamol and glutamine(based on the expired drugs)were selected as vapor-phase corrosion inhibitors(VCIs)to study their corrosion protection effect on red copper in simulated marine atmospheric environment by using weight loss,electrochemical measurement techniques(specially designed electrochemical testing device for simulating marine atmospheric environments)and surface morphology characterization analysis(SEM/EDS,XRD,RAMAN,XPS).Weight loss results show that the three corrosion inhibitors have good corrosion inhibition effect on red copper,and the corrosion inhibition efficiency in the order of glutamine(83.62%)>urea(68.46%)>paracetamol(61.47%).Surface morphology characterization analysis provides evidence of adsorption of corrosion inhibitors molecules on the red copper surface,thus forming a protective film that blocked the red copper surface from the aggressive chloride ion attack.

铜制仪器设备在海洋大气环境中面临着严重的腐蚀问题,使用气相缓蚀剂能够有效抑制铜金属的腐蚀,延长铜制仪器设备的使用寿命。一些传统的高效铜缓蚀剂,如苯并三唑和噻二唑及其衍生物,难以生物降解,而且价格昂贵,在使用过程中受到限制。尿素、对乙酰氨基苯酚和谷氨酰胺中均含酰胺基团,可以和紫铜形成配合物吸附在紫铜表面。因此,本文选用这三种过期药品作为气相缓蚀剂,通过腐蚀失重、电化学性能测试和SEM/EDS、XRD、RAMAN、XPS等表征手段研究它们在模拟海洋大气环境中对紫铜的缓蚀作用。腐蚀失重实验结果显示,谷氨酰胺的缓蚀效率最高(83.62%),其次是尿素(68.46%)、对乙酰氨基苯酚(61.47%)。研制了一种模拟海洋大气环境中的电化学测试装置,利用其进行电化学测试,发现三种气相缓蚀剂的加入能显著降低紫铜的自腐蚀电流,且紫铜腐蚀电位变化均低于85 mV,说明三种气相缓蚀剂类型为混合型抑制剂。SEM/EDS、XRD、RAMAN、XPS表征分析证实了缓蚀剂分子中酰胺基团可以与Cu~(2+)螯合形成配合物,吸附在紫铜表面形成保护膜,有效阻止紫铜表面受到腐蚀介质的侵蚀。各项实验结果表明,所选取的三种过期药品气相缓蚀剂具有良好的缓蚀性能,可实现对铜制仪器设备的有效保护。