通过分子结构设计,合成了一种阳离子型咪唑啉季铵盐钢筋混凝土迁移性阻锈剂,对其分子结构及其在含3.5%Cl-的模拟混凝土孔溶液中对钢筋的防腐蚀性能进行了研究,并初步探讨其阻锈机理.结果表明:合成产物与设计的分子结构一致,合成产率达95%;合成的咪唑啉季铵盐是一种阳离子型阻锈剂,在模拟混凝土孔溶液中具有良好的钢筋防蚀效果,其掺量为1.0%时,阻锈效果略低于掺2.0%无机阻锈剂亚硝酸钠的效果,优于掺量同为2.0%的醇胺类有机阻锈剂;腐蚀早、中期(1、7、14 d),掺1.0%的阳离子型咪唑啉季铵盐的阻锈效果较好,28d后,掺2.0%阳离子型咪唑啉季铵盐的阻锈效果较好;合成的阳离子型咪唑啉季铵盐阻锈机理主要为在钢筋表面吸附成膜并抑制其电化学反应过程中的阴极反应.
Cationic imidazoline quaternary-ammonium-salt was synthesized as a corrosion inhibitor of reinforced concrete by means of the molecular structure design. Then, its molecular structure and corrosion inhibition perfor- mance on the steel reinforcement in the simulated concrete pore solution with 3.5 % of NaC1 were characterized, and the corresponding corrosion inhibition mechanism was preliminarily discussed. The results indicate that ( 1 ) the synthesized product is consistent with the designed molecular structure, and the corresponding yield is up to 95% ; (2) the synthesized imidazoline quaternary-ammonium-salt is a cationic corrosion inhibitor with a good inhibition effect on the corrosion of steel reinforcement in the simulated concrete pore solution, specifically, the corrosion in- hibition effect of the salt with a dosage of 1.0% is slightly inferior to that of the inorganic corrosion inhibitor sodium nitrite with a dosage of 2.0%, while that of the salt with a dosage of 2.0% is superior to that of the alcohol-amine organic corrosion inhibitors with the same dosage; (3) the salt with a dosage of 1.0% displays a better corrosion inhibition effect in the early and middle stages (1, 7, 14d) , while the salt with a dosage of 2. 0% does after 28 days; and (4) the corrosion inhibition mechanism of the salt can be described as the adsorption and film-forming on the steel surface and the inhibition of the cathodic reaction of the steel reinforcement.