改性木质素磺酸盐GCL2-D1的缓蚀机理  

Corrosion inhibition mechanism of modified lignosulfonate GCL2-D1

作　　者：易聪华[1] 邱学青[1] 杨东杰[1] 楼宏铭[1] 

机构地区：[1]华南理工大学制浆造纸工程国家重点实验室、化学与化工学院,广东广州510640

出　　处：《化工学报》2009年第4期959-964,共6页CIESC Journal

基　　金：广东省自然科学基金项目(8351064101000002);广东省科技攻关项目(2008B010600014);国家自然科学基金项目(20876064)~~

摘　　要：采用凝胶渗透色谱、化学滴定法、紫外差示光谱法、环境扫描电镜、交流阻抗谱、俄歇能谱等方法研究了改性前后木质素磺酸盐的结构特征和缓蚀性能,揭示了缓蚀作用机理。改性后木质素磺酸盐的分子量从11048提高到29381,磺酸基含量从9.04%提高到11.2%,羧基含量从5.81%提高到15.84%,在溶液中的构型由球状变为直链状,在金属表面吸附膜层S、Ca、C含量均增加,表明改性木质素磺酸盐在金属表面吸附点增多,吸附量增大。电化学测试结果表明改性木质素磺酸盐(简称GCL2-D1)属于混合抑制型缓蚀剂,腐蚀介质中掺加100mg·L-1 GCL2-D1能使腐蚀过程电荷传递电阻从564Ω增加至20680Ω,金属/溶液界面电容从2.84mF降低至0.041mF,说明改性后的木质素磺酸盐能够在金属表面形成致密的膜层,从而抑制金属腐蚀。The corrosion inhibition mechanism of modified lignosulfonate GCL2-D1 was studied by using methods of GPC, titration, differential UV-absorption spectrum, ESEM, EIS, etc. The results showed that the structure and corrosion inhibition properties of the lignosulfonate changed greatly after modification. The molecular weight changed from 11048 to 29381. The sulfonic content increased from 9.04% to 11.2%, and the carboxyl content increased from 5.81% to 15.84%. Through modification, the lignosulfonate extended itself in the solution from spherical shape to linear chains. When adsorbed on metal surface, the contents of S, Ca, and C had an obvious increase in the interracial film, indicating the increase of adsorption points and adsorption amount of the modified lignosulfonate GCL2-D1. Electrochemical analysis demonstrated that GCL2-D1 belonged to mixed inhibitor. When the dosage of GCL2-D1 was 100 mg·L^-1, the charge transfer resistance increased from 564 Ω to 20680Ω, and the interracial capacity between metal and solution reduced distinctly from 2.84 mF to 0. 041 mF. It indicated that the GCL2-D1 formed a compact film on the metal surface, resulting in inhibition of metal corrosion.

关 键 词：改性木质素磺酸盐 缓蚀机理 电化学 

分 类 号：TQ351.013[化学工程]