ACORUS CALAMUS L. (SWEET FLAG) IS A WETLAND PERENNIAL MONOCOT PLANT, IN WHICH THE SCENTED LEAVES AND RHIZOMES HAVE BEEN TRADITIONALLY USED MEDICINALLY AGAINST DIFFERENT AILMENTS LIKE, FEVER, ASTHMA, BRONCHITIS, AND COUGH AND MAINLY FOR DIGESTIVE PROBLEMS...

USE OF INHIBITORS IS ONE OF THE MOST PRACTICAL METHODS FOR PROTECTION AGAINST CORROSION ESPECIALLY IN ACID SOLUTIONS TO PREVENT UNEXPECTED METAL DISSOLUTION AND ACID CONSUMPTION [1]. DIFFERENT ORGANIC AND INORGANIC COMPOUNDS HAVE BEEN STUDIED AS INHIBITORS TO PROTECT METALS FROM CORROSION ATTACK. THESE NATURAL ORGANIC COMPOUNDS ARE EITHER SYNTHESIZED OR EXTRACTED FROM AROMATIC HERBS, SPICES AND MEDICINAL PLANTS. PLANT EXTRACTS ARE VIEWED AS AN INCREDIBLY RICH SOURCES OF NATURALLY SYNTHESIZED CHEMICAL COMPOUNDS THAT CAN BE EXTRACTED BY SIMPLE PROCEDURES WITH LOW COST AND ARE BIODEGRADABLE IN NATURE. THEUSE OF THESE NATURAL PRODUCTS SUCH AS EXTRACTED COMPOUNDS FROM LEAVES OR SEEDS AS CORROSION INHIBITORS HAVE BEEN WIDELY REPORTED BY SEVERAL AUTHORS [2]. THE INHIBITION EFFECT OF ACORUS CALAMUS CRUDE EXTRACT WAS INVESTIGATED FOR COPPER CORROSION IN 0.5M HCL MEDIUM. POTENTIODYNAMIC POLARIZATION AND ELECTROCHEMICAL IMPEDANCE WERE EMPLOYED FOR THIS STUDY. RESULTS SHOWED THAT CRUDE EXTRACTS REDUCED THE CORROSION RATE SIGNIFICANTLY AT ALL CONCENTRATIONS. POLARIZATION MEASUREMENTS INDICATED THAT THESE GREEN INHIBITORS ACTED THROUGH MIXED TYPE INHIBITION. THE INHIBITION EFFICIENCY OF COPPER IN 0.5 M HCL INCREASES BY INCREASING THE CONCENTRATION OF ACORUS CALAMUS. INHIBITION EFFICIENCY UP TO 95% HAS BEEN ACHIEVED FOR 1.6 G/L ACORUS CALAMUS AT 25OC. ACORUS CALAMUS IS EFFECTIVE IN REDUCING CORROSION OF COPPER IN THE TEMPERATURE RANGE OF 25-65OC. POLARIZATION STUDIES SHOWED THAT ACORUS CALAMUS ACTS AS A MIXED-TYPE INHIBITOR WITHOUT MODIFYING THE MECHANISM OF HYDROGENEVOLUTION.