Fortification performance of polyurethane coating in outdoor historical ironworks

Bulletin of the National Research Centre

Y. Reda¹  M. Abdelbar²  A. M. El-Shamy³ 

[1] Chemical Engineering Department, Canal High Institute of Engineering and Technology, Higher Institute of Engineering and Technology Tanta, Tanta, Egypt;Conservation Department, Faculty of Archaeology, Damietta University, 34511, Damietta El-Gadeeda City, Damietta Governorate, Egypt;Electrochemistry and Corrosion Lab., Physical Chemistry Department, National Research Centre, P.O. 12622, El-Bohouth St. 33, Dokki, Giza, Egypt;

关键词: Polyurethane coating;    Ironworks;    Surface characterization;    Corrosion control;    Conservation;   

DOI  :  10.1186/s42269-021-00532-y

来源: Springer

【 摘 要 】

BackgroundIronworks in the tomb of Suleiman Pasha Al-Faransawi (located in the old Cairo, Egypt) were exposed in the open-air are susceptible to various corrosion factors, which be contingent on the environmental conditions wherein the artifacts are displayed and the existence of a protective layer or not. Examinations and analysis were conducted to identify the structure and type of the alloys used in making the decorative ironworks, to identify the manufacturing technique and decoration, and to study the nature of rust compounds. This has been achieved by using metallographic microscopy, X-ray diffraction, and a carbon–sulfur analyzer. Many protection approaches have been worked such as varnishes, waxes, and oils, but they have had many disadvantages. The aim of this paper is to assess the competence of polyurethane coating by using electrochemical measurements (electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization) in the fortification of ironworks exposed in the outdoor environment.ResultsThe results confirmed that the decorative ironworks were manufactured from wrought and gray cast iron. The main corrosion products identified by XRD are goethite, akageneite, and maghemite. Lead oxide hydrate refers to old lead paints (red primer) which have been applied to protect the ironworks. Quartz and calcite are the products of heavy dust particles that covered the surface.ConclusionThe data proved that the polyurethane is acting as a good protective coating for the decorative ironworks exposed in an uncontrolled environment. The 2% is considered as the recommended dose for this polymer for the minimum corrosion rate of the ironworks.

【 授权许可】

CC BY