天然气管道内表面超疏水分子膜及其防腐性能

Super-hydrophobic molecular film on the inner wall surface of steel for natural gas pipelines and its corrosion resistance

采用硅氧烷的复配物作为改性剂,使天然气管道内壁表面形成致密的超疏水分子膜,以达到管道防腐的目的。从天然气管道上取得管材试样,对改性前后的试样表面进行红外光谱和接触角测试,利用不同酸度值的5%NaCl和5%NaCl-HCl水溶液,对改性前后的管道内壁表面进行腐蚀实验。结果表明:天然气管道内壁表面由多种FeOOH、α-Fe2O3、FeCO3及少量Fe3O4组成;改性后,管道内壁表面与硅氧烷发生化学反应,复配物的碳链分子以化学键形式与管道内壁表面联接,形成超疏水分子膜,接触角大于160°,具有良好的防腐性能。硅氧烷复配物易于雾化,在湿气输送管道及其他具一定湿度的天然气管道内壁缓蚀或防腐上,具有一定的发展潜力。

In this paper,the complex of siloxanes was used as the modifying agent to form a dense layer of anticorrosion film upon the inner wall surface of steel for natural gas pipeline by direct spraying process.The testing of infra-red spectrometry and contact angle revealed that the inner wall surface of steels which were taken from the field natural gas pipeline was composed of multiform FeOOH,FeCO3,α-Fe2O3 and a trace of Fe3O4.After being modified,the steel inner wall surface was coupled with a layer of super-hydrophobic f ilm with alkyl chains towards the surface by the chemical reaction of steel surface and siloxanes.The average contact angle of the super-hydrophobic film was over 160°.The results of corrosions around the modified steel inner surfaces by 5wt% NaCl aqueous solution with different acidities indicated that the formed super-hydrophobic f ilm was dense and stable,and had excellent anticorrosion properties.The complex of siloxanes used here is easily atomized and has a potential in corrosion inhibition or anticorrosion for wet gas transmission pipelines and natural gas pipelines with certain humidity.