Green Recycling of Poly(ethylene terephthalate) Waste as Corrosion Inhibitor for Steel in Marine Environment

Abstract

Green recycling of poly(ethylene terephthalate) plastic waste, in this respect, PET waste was subjected to de polymerization process with tri methylene glycol (1,3-propandiol) in the presence of manganese acetate (1.0 % w/w to the total Wight of the reactants) as trans esterification catalyst, the product is Bis-(3-hydroxy-propyl)-terephthalate, BHPT, as a non-ionic surfactant was separated and characterized by FT-IR and 1HNMR and evaluated as corrosion inhibitor for carbon steel alloy in artificial marine environment using chemical and electrochemical techniques. Effect of inhibitor concentrations and reaction temperature were studied. The chemical techniques used in this work are gravimetric, thermometric and atomic absorption spectroscopy(AAS), whereas the electrochemical techniques are open circuit potential, potentiodynamic polarization. The corrosion inhibition efficiency increases with increasing inhibitor concentrations and decreased by rising temperature. The maximum corrosion inhibition efficiency 96.5% was afforded using 300 ppm of the used inhibitor derived from plastic waste. Potentiodynamic polarization curves indicate that the used system act as mixed inhibitor. The data of AAS show that the iron(iii) ions Fe+3 concentrations were decreased by increasing inhibitor concentration. All the used techniques are in good agreement to each other (±2 %) and shows that the used drug acts as green corrosion inhibitors for steel in marine environment.