An efficient corrosion inhibitor of cassava starch graft copolymer for aluminum in phosphoric acid

• Published in: Chinese journal of chemical engineering Vol. 37; no. 9; pp. 222 - 231
• Main Authors: Deng, Shuduan, Li, Xianghong, Du, Guanben
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.09.2021; Yunnan key laboratory of wood adhesives and glue products,Southwest Forestry University,Kunming 650224,China%College of Chemical Engineering,Southwest Forestry University,Kunming 650224,China
• Subjects: Aluminum; Corrosion; Electrochemistry; Inhibitor; Phosphoric acid; Polymers; Electrochemistry; Phosphoric acid; Inhibitor; Corrosion; Polymers; Aluminum; Rice (Oryza sativa L.); Saline-alkaline stress; Abscisic acid (ABA); Endogenous ABA levels; OsABA8ox1-kd
• ISSN: 1004-9541; 2210-321X
• DOI: 10.1016/j.cjche.2020.08.013

Starch is one of the richest natural polymers with low-cost, non-toxic and biodegradable, but is seldom directly used as corrosion inhibitor due to its poor inhibitive ability and low water solubility. To solve this problem, cassava starch-acryl amide graft copolymer (CS-AAGC) was prepared through grafting acryl amide (AA) with cassava starch (CS), and it was firstly examined as an efficient inhibitor for 1060 aluminum in 1.0 mol·L−1 H3PO4 media. The adsorption behavior of CS-AAGC and its electrochemical mechanism were investigated by weight loss and electrochemical methods. Additionally, the inhibited aluminum surface was fully characterized by a series of SEM, AFM, contact angle measurements and XPS. Results confirm that CS-AAGC performs better inhibitive ability than CS, AA or CS/AA mixture, and the maximum inhibition efficiency of 1.0 g·L−1 CS-AAGC is 90.6% at 20 °C. CS-AAGC acts as a mixed-type inhibitor while mainly retards the anodic reaction. EIS has three time constants, and the polarization resistance is significantly increased in the presence of CS-AAGC. The micrograph of inhibited aluminum surface is of hydrophobic nature with low surface roughness and little corrosion degree. [Display omitted]