阻锈剂对聚合物水泥基涂层耐蚀性的影响机制  

Effect Mechanism of Corrosion Inhibitor on Corrosion Resistance of Polymer Cement-based Coating

作　　者：葛津宇 袁聪 胡家宇 周成洋 韦华[1] 韩雪松 GE Jin-yu;YUAN Cong;HU Jia-yu;ZHOU Cheng-yang;WEI Hua;HAN Xue-song(Materials&Structural Engineering Department,Nanjing Hydraulic Research Institute,Nanjing 210029,China;Jiangsu Huaishuxin River Administration Office,Huaian 223001,China)

机构地区：[1]南京水利科学研究院材料结构研究所,南京210029 [2]江苏省淮沭新河管理处,淮安223001

出　　处：《科学技术与工程》2023年第10期4331-4338,共8页Science Technology and Engineering

基　　金：新沂河海口枢纽水利科技项目(HKZJG-KY-01);中央级公益性科研院所基本科研业务费专项(Y422002)。

摘　　要：氯离子侵蚀严重威胁沿海地区钢筋混凝土构件的耐久性。提升钢筋的抗锈蚀能力可显著增强构件整体的耐久性能。对此,以丙乳与P·O 52.5水泥质量比1∶2的聚合物水泥基涂层为基础研究对象,通过单掺及复掺亚硝酸钠、钼酸钠以及单氟磷酸钠,制备复合涂层,基于电化学试验,探究各复合涂层对钢筋的阻锈机理,进一步分析无机阻锈剂对聚合物水泥基涂层耐腐蚀性能的交互影响。单掺试验结果表明,虽然涂层中丙乳的碱性基团为钢筋表面形成钝化膜提供了有利条件,但钼酸钠的加入会破坏生成的钝化膜的致密性。同样的,若仅少量单独掺入单氟磷酸钠,会导致其与水泥或钢基体反应所生成的Ca_(3)(PO_(4))_(2)与Fe_(3)(PO_(4))_(2)含量不足,无法保障钝化膜的顺利成型,因而单掺钼酸钠或单氟磷酸钠均无法显著提升复合涂层的阻锈性能。而亚硝酸钠可与锈蚀产物直接反应生成新钝化膜,可有效地延缓锈蚀发展,因此亚硝酸钠在单掺组分中表现出最佳阻锈性能。合理复掺条件下,亚硝酸钠与单氟磷酸钠对聚合物水泥基涂层抗锈蚀效果存在协调与兼容效应,并存在一定的增益互馈机制。一方面,涂层中单氟磷酸钠在阻锈过程中可参与生成Ca_(3)(PO_(4))_(2)与Fe_(3)(PO_(4))_(2)以确保Fe_(3)O_(4)钝化膜生成,另一方面,当钢基体由于涂层中单氟磷酸钠含量不足产生锈蚀后,涂层中的亚硝酸钠可与锈蚀产物反应生成Fe_(2)O_(3)与γFeOOH,为钢基体继续提供保护。其中,亚硝酸钠与单氟磷酸钠质量比为1∶3时,复合涂层表现出最佳阻锈性能;钼酸钠不适合掺入聚合物水泥基涂层。The durability of reinforced concrete members in coastal areas is threatened by chloride ion erosion seriously.The durability of the whole members can be significantly enhanced by improving the corrosion resistance of steel bars.Thus,the polymer cement-based coating that the mass ratio of acrylic emulsion to P·O 52.5 cement is 1∶2 was used as the basic research object,and the composite coating was prepared by single-doping and co-doping sodium nitrite,sodium molybdate and sodium monofluorophosphate.Based on electrochemical test,the rust resistance mechanism of each composite coating on steel bars was investigated,and the interaction effect of inorganic corrosion inhibitor on the corrosion resistance of polymer cement-based coating was further analyzed.The results of single-doping test show that,although the good conditions are provided by the basic reactive of acrylic emulsion in the coating for the formation of passivation film on the surface of steel bar,the compactness of the passivation film is weakened by adding sodium molybdate.Similarly,if only a small amount of sodium monofluorophosphate is added alone,Ca_(3)(PO_(4))_(2)and Fe_(3)(PO_(4))_(2)generated by the reaction between sodium monofluorophosphate and cement or steel matrix is insufficient,which can't guarantee the successful formation of passivation film.Therefore,the corrosion resistance of composite coating can't be improved by single-doping sodium molybdate or sodium monofluorophosphate significantly.And the new passivation film can be generated by the direct reaction of sodium nitrite with corrosion products,which can effectively delay corrosion.As a result,the best anti-corrosion performance of sodium nitrite among the single-doped components is showed.In the reasonable co-doping conditions,there is coordination and compatibility effect of sodium nitrite and sodium monofluorophosphate on corrosion resistance of polymer cement-based coating.And a certain mechanism of gaining mutual feeding exists.On the one hand,sodium monofluorophosphate in t

关 键 词：钢筋锈蚀 聚合物水泥基涂层 无机阻锈剂 电化学试验 

分 类 号：TU593[建筑科学—建筑技术科学]