ENHANCING THE ANTICORROSIVE AND ANTIMICROBIAL ACTIVITIES OF POLYURETHANE COATING USING 4-NITRO-O-PHENYLENEDIAMINE COUPLED WITH APTMS-SiO2

The research explores the synthesis and properties of polyurethane-urea coatings derived from castor seed oil (CSO), Toluene diisocyanate (TDI) and 4-nitro-o-phenylenediamine (4NPD) as a sustainable alternative to petrochemical-based polymers. Given the increasing environmental concerns and the need for biodegradable materials, this study focuses on utilising renewable plant biomass materials, particularly non-edible vegetable oils, to produce environmentally friendly polymeric coatings. The experimental approach involved the synthesis of poly(epichlorohydrin-triol) (PECH-triol) and its subsequent reaction with CSO and toluene diisocyanate (TDI) to form polyurethane. The inclusion of 4NPD and APTMS-SiO2 aimed to enhance the attendant properties of the resultant coatings. Comprehensive analyses were conducted to characterise the synthesised materials. Fourier Transform Infrared Spectroscopy (FT-IR) and Nuclear Magnetic Resonance (NMR) confirmed the successful incorporation of 4-nitro-o-phenylenediamine 4NPD and APTMS-SiO2 into the polyurethane matrix. X-ray Diffraction (XRD) analysis revealed the crystallinity of the coatings. The salt spray test shows that the more the nanomaterial, the higher it resists corrosion. The water contact angle demonstrates that the 3% APTMS-SiO2 is more hydrophobic than the others, while Thermogravimetric Analysis (TGA) demonstrated their thermal stability. Furthermore, antimicrobial tests showed significant activity against various bacterial and fungal strains. It is hereby concluded that 4NPD enhances the coating strength and adhesives. It was also observed that PUU-ASiO2 with 3% ASiO2 show a more substantial effect on the attendant property of Polyurethane-urea coatings

Development of functional graphene oxide-urethane coating systems from Ricinus communis seed oil

The surface-modified graphene oxide (GO) nanoparticles and their blending with a fixed percentage of trimethylopropane (TMP) in Ricinus communis seed oil were successfully prepared in a one-pot urethane reaction using 4,4′-diisocyanato dicyclohexylmethane (H12MDI) and methyl isobutyl ketone (MIBK) as the reaction solvent. The structural elucidation and surface morphology of pristine and hybrid composites of the polyurethane coating films were investigated with the aid of Fourier transform infrared spectroscopy (FT-IR), Energy-dispersive X-ray spectroscopy (EDX), Proton nuclear magnetic resonance (1H NMR), X-ray diffraction (XRD), and Scanning electron microscope (SEM). The presence of FT-IR absorption peaks at 790 cm−1 to 870 cm−1, 990 cm−1, and 1017 cm−1 confirms the following functional groups phenyl -CH bend, stretching phenolic -CO, and epoxyl -C-O-C, respectively in modified graphene oxide. An evaluation of the thermal stability of the coating films that were synthesised was carried out with the use of a thermogravimetric analyzer (TGA). It was seen that as the amount of modified graphene oxide in the urethane films increased, so did the water contact angle from 0% to 0.5%. Antimicrobial and anticorrosive properties of the materials were also evaluated