Development of Castor Oil Based Poly(urethane-esteramide)/TiO2 Nanocomposites as Anticorrosive and Antimicrobial Coatings

Castor oil based polyesteramide (CPEA) resin has been successfully synthesized by the condensation polymerization of N-N-bis (2-hydroxyethyl) castor oil fatty amide (HECA) with terephthalic acid and further modified with different percentages of 7, 9, 11, and 13wt.% of toluene-2,4-diisocyanate (TDI) to obtain poly(urethane-esteramide) (UCPEA), via addition polymerization. TiO2 (0.1, 0.2, 0.3, 0.4, and 0.5 wt%) nanoparticles were dispersed in UCPEA resin. The structural elucidation of HECA, CPEA, and UCPEA has been carried out using FT-IR, H-1-NMR, and C-13-NMR spectroscopic techniques while physicochemical and physicomechanical properties were investigated by standard methods. Thermal stability and molecular weight of UCPEA have been assessed by thermogravimetric analysis (TGA) and gel permeation chromatography (GPC), respectively. Furthermore, the corrosion behavior of UCPEA coatings on mild steel has been investigated by potentiodynamic polarization measurements in different corrosive environments (3.5 wt% HCl, 5 wt% NaCl, 3.5wt% NaOH, and tap water) at room temperature and surface analysis by scanning electron microscope (SEM) and energy dispersive X-ray (EDX). Theantibacterial activities of the UCPEA were tested against bacteria and fungi by agar disc diffusionmethod. The results of this study have revealed that UCPEA nanocomposite coatings exhibit good physicomechanical, anticorrosion and antimicrobial properties, which can be safely used up to 200 degrees C.