296 Electrochemical Comparing the Effect of Frula-Asafotedia and it s Nanocomposite with Chitosan on Cu Corrosion.

Corrosion of metals and alloys is an important industrial problem specialty in our country, Iran. Different organic and inorganic compounds containing N, O and S atoms are invest used as effective corrosion inhibitors [1]. Unfortunately, most of the organic inhibitors are toxic, very expensive and environmentally unfriendly. Therefore, recently some research is oriented to the development of green corrosion inhibitors with good efficiency and low risk of environmental pollution. Plant s extracts are containing mixtures of compounds such as N and S as constituent atom were studied as corrosion inhibitor and are biodegradable in nature [2]. In other hand, in recent years, there has been considerable interest in developing biodegradable nanoparticles and nanocomposites for increase inhibition efficiency. In present work, we synthesis nanocomposite of chitosan with essential oil of Ferula Asafotedia (F.Af) (anghouzeh in Persian). Then have studied the corrosion resistance of Cu plate in 3.5% salt solution in presence of Asafotedia (Af) alone and nanocompsite it with chitosan. F.Af is one of the most important species of Iranian Ferula which grows wildly in several areas of Iran. Af is the oleo-gum resin which is exudates from F.Af. The gums were also known as green corrosion inhibitors [3]. Chitosan (Ch) is a natural polymer easily extracted from the shells of crustaceans. The anticorrosive behavior of chitosan is attributed to the presence of hydroxyl and amino groups, but it exhibits low inhibition efficiency if it is used alone [4]. Chitosan is receiving a lot of interest in the encapsulation of bioactive compounds due to its biocompatibility, low toxicity and biodegradability. For synthesis of nanocomposite, after extract oil of Af using Clevenger, Chitosan/essential oil of Af (COA) nanocomposite, were prepared according to a procedure modified from the ones reported by Esmaeili et al [5], and was characterized with different techniques. Electrochemical corrosion behavior of sealed epoxy resin Cu specimen with 1 cm2 area were evaluated in 3.5 13th Annual Electrochemistry Seminar of Iran Materials and Energy Research Center (MERC), 22- 23 Nov, 2017 297 wt.% NaCl solution in absence and presence 1 g/l of As or COA nanocomposite with three electrode cell using a potentiostate/galvanostate model IVIUM. The corrosion resistance of solutions were analyzed by Tafel plot (Fig 1a) and electrochemical impedance spectroscopy (EIS) (Niquist plot, Fig 1b) measurements. Fig 1. Tafel plot (a) and Niguist plot (b) of Cu in 3.5% salt alone (0) and in presence of 1 g/l resin Asafotedia (Af), Chitosan nanoparticles (Ch-Np) and COA nanocomposite (COA-Nc). As observed in Fig. 1a shift of corrosion potential and decrease in current (Icorr) indicates the higher corrosion resistance property of the Cu specimen in presence of Af and COA composite. Also Fig 1b show that Cu in solution of Af and COA composite has larger charge transfer resistance (Rct) (diameter in the semicircle in middle frequency range) than 3.5% salt solution alone.