title: Experimental and theoretical studies on inhibition of mild steel corrosion by some synthesized polyurethane tri-block co-polymers.
abstract: Polyurethane based tri-block copolymers namely poly(N-vinylpyrrolidone)-b-polyurethane-b-poly(N-vinylpyrrolidone) (PNVP-PU) and poly(dimethylaminoethylmethacrylate)-b-polyurethane-b-poly(dimethylaminoethylmethacrylate) (PDMAEMA-PU) were synthesized through atom transfer radical polymerization (ATRP) mechanism. The synthesized polymers were characterized using nuclear magnetic resonance (NMR) spectroscopy and gel permeation chromatography (GPC) methods. The corrosion inhibition performances of the compounds were investigated on mild steel (MS) in 0.5 M H2SO4 medium using electrochemical measurements, surface analysis, quantum chemical calculations and molecular dynamic simulations (MDS). Potentiodynamic polarization (PDP) measurements revealed that the polymers are mixed-type corrosion inhibitors. Electrochemical impedance spectroscopy (EIS) measurements showed that the polymers inhibit MS corrosion by adsorbing on MS surface to form pseudo-capacitive interface. The inhibitive effects of the polymers increase with increasing concentration and decrease with increasing temperature. The adsorption of both the polymers on MS surface obey the Langmuir adsorption isotherm and involves both physisorption and chemisorption mechanisms. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) analyses showed that the polymers formed protective film on MS surface and shield it from direct acid attack. Quantum chemical calculations and molecular dynamic simulations studies corroborate experimental results.
authors: Department of Chemistry, Hindu College, University of Delhi, Delhi, 110007, India.
authors: Sudershan
authors: S
authors: Kumar
authors: Department of Chemistry, Maharaja Agarsen College,University of Delhi, Delhi, 110007, India.
authors: Hemlata
authors: H
authors: Vashisht
authors: Department of Chemistry and Material Science Innovation &Modelling (MaSIM) Research Focus Area, Faculty of Agriculture, Science and Technology, North-West University (Mafikeng Campus), Private Bag X2046, Mmabatho 2735, South Africa.
authors: Lukman O
authors: LO
authors: Olasunkanmi
authors: Department of Chemistry and Material Science Innovation &Modelling (MaSIM) Research Focus Area, Faculty of Agriculture, Science and Technology, North-West University (Mafikeng Campus), Private Bag X2046, Mmabatho 2735, South Africa.
authors: Indra
authors: I
authors: Bahadur
authors: Department of Chemistry, Hindu College, University of Delhi, Delhi, 110007, India.
authors: Hemant
authors: H
authors: Verma
authors: Department of Chemistry, University of Delhi, Delhi, 110007, India.
authors: Gurmeet
authors: G
authors: Singh
authors: Centre of Research Excellence in Corrosion, Research Institute, King Fahd University of Petroleum and Minerals, Dhahran 31261, Kingdom of Saudi Arabia.
authors: Ime B
authors: IB
authors: Obot
authors: Department of Chemistry and Material Science Innovation &Modelling (MaSIM) Research Focus Area, Faculty of Agriculture, Science and Technology, North-West University (Mafikeng Campus), Private Bag X2046, Mmabatho 2735, South Africa.
authors: Eno E
authors: EE
authors: Ebenso