%0 Journal Article
%T Water-Soluble and Biodegradable Pectin-Grafted Polyacrylamide and Pectin-Grafted Polyacrylic Acid: Electrochemical Investigation of Corrosion-Inhibition Behaviour on Mild Steel in 3.5% NaCl Media
%A R. Geethanjali
%A A. Ali Fathima Sabirneeza
%A S. Subhashini
%J Indian Journal of Materials Science
%D 2014
%R 10.1155/2014/356075
%X Pectin-g-polyacrylamide (denoted as Pec-g-PAAm) and pectin-g-polyacrylic acid (denoted as Pec-g-PAA) were synthesized using pectin, acrylamide, and acrylic acid as starting materials. The grafted polymers were characterized using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analyser (TGA), and scanning electron microscopy (SEM). The corrosion inhibition behaviour of the grafted polymers on mild steel in 3.5% NaCl was evaluated electrochemically through Tafel polarization and impedance studies. The corrosion inhibition performance of both the polymers was found to be around 85%. 1. Introduction The importance of mild steel is well known owing to its cost, process-ability, and weld-ability when used for infrastructures in marine environments like ship hulls, oil rings, off-shore platforms, coastal facilities and sheet piling, and so forth. The mild steel is preferred over stainless steel in chloride environments, because the cost of stainless steel good enough to resist corrosion is far too great. There are several advantages in selecting the mild steel, but it still suffers uniform or generalised corrosion, which is of considerable economic importance. The corrosion inhibition mechanism involves strong adsorption of inhibitor molecules on the active sites of metal and thereby preventing cathodic and anodic reactions of the metal. Polymers are selected for corrosion inhibition because of the superior performance when compared with their monomer analogues in active adsorbing on the corrosive sites of the metal [1]. The improved performances of the polymeric materials are ascribed to their multiple adsorption sites for bonding with the metal surface. The polymer provides two advantages: a single polymeric chain displaces many water molecules from the metal surface, thus making the process entropically favourable and the presence of multiple bonding sites makes the desorption of the polymers a slower process [2]. Research activities in recent times are geared towards revealing green corrosion inhibitors to replace the toxic inorganic and organic compounds. Naturally occurring substances have been found to readily satisfy this need. Apart from being readily available, cheap, and a renewable source of materials, naturally occurring substances are eco-friendly and ecologically acceptable [3]. Xu et al. [4] synthesized polyaspartic acid-melamine (PASPM) grafted copolymer and evaluated its CaCO3 and Ca3(PO4)2 scale inhibition performance and dispersion capacity for ferric oxide. The PASPM copolymer efficiently inhibited CaCO3 scale and
%U http://www.hindawi.com/journals/ijms/2014/356075/