Effects of Nanoclay and Polyurethanes on Inhibition of Mild Steel Corrosion

Abstract

Sulfonated polyurethanes (SPU) were used as corrosion inhibitor for mild steel in acidic solution. The sulfonation of the > N-H groups of the urethane linkages was confirmed from Nuclear Magnetic Resonance (NMR) and Fourier Transform Infra Red (FTIR) spectroscopic techniques. The inhibition efficiency of sulfonated polyurethanes, prepared from two different routes, was investigated using different techniques. The effects of microstructure of polyurethane (PU), degree of sulfonation, time of immersion and temperature on the inhibition of corrosion were discussed. The disc-like nanoparticles, so-called nanoclay, either suspended or chemically attached to SPU chains (nanocomposites) dramatically enhanced the inhibition efficiency for mild steel in acidic medium. All the inhibitors retard the corrosion rate by getting themselves adsorbed on the corroding surface by following the Langmuir adsorption isotherm. The surface analysis of inhibited and uninhibited samples was performed using Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). Among the various inhibitors used, the nanocomposite of polyurethane was the most effective. Molecular modeling helped in determining the extent of packing of the SPU chains leading to better inhibition efficiency.

Morphology of polyurethanes at various length scale: The influence of chain structure

“…Segmented polyurethanes are intriguing class of thermoplastic elastomers1–4 which was initially developed as a replacement for rubber but now it is utilized in the production of high‐performance elastomeric product. It has potential use in biomedical tissue engineering,5, 6 molecular recognition,7 biocompatible materials, durable coating,8 and shape memory materials 9–12. Structure property correlation is the prime prospective arises due to thermodynamic incompatibility between the hard and soft segments.…”

Functionalized polythiophene for corrosion inhibition and photovoltaic application

“…The linear Tafel segments of the anodic and cathodic curves were extrapolated to obtain corrosion potential and corrosion current densities (). The inhibitor efficiency ) evaluated from the measured values using the following relationship Equation () 45 ; where, and are the corrosion current densities without and with inhibitors, respectively.…”

New Generation Fuel Cell Membrane Using Swift Heavy Ions

“…Interestingly, this band shifts to longer wave length (red shift) after grafting at 262 nm in grafted nanohybrid (NH‐g) which also corroborates the polystyrene grafting on PVDF chains (π→π * transition arising from benzene ring of polystyrene) ,. A broad peak at 381 nm in sulfonated nanohybrid (NH‐g‐s) is presumably due to n→π * transition of sulphonate group, against the peak observed at 374 nm for PVDF‐g‐s. However, it is apparent that two new peaks at 262 and 381 nm after grafting and sulfonation (in NH‐g‐s) against no peak for pure PVDF suggest the tagging of polystyrene and subsequent functionalization / sulfonation in PVDF chains.…”