Development and potential performance of prepolymer in corrosion inhibition for carbon steel in 1.0 M HCl: Outlooks from experimental and computational investigations.

Diglycidyl amino benzene (DGAB) epoxy prepolymer was investigated using Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopy. Then, we highlighted the usefulness of DGAB epoxy prepolymer to improve the resistance of carbon steel (CS) in hydrochloric acid (1.0 M HCl) using weight loss (WL), electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), scanning electron microscope (SEM), atomic force microscopy (AFM), density functional theory (DFT) and complexation calculations, molecular dynamics (MD) and meansquaredisplacement (MSD) simulations. Highest inhibitory efficiencies for the WL, EIS and PDP methods at 10-3 M of DGAB are 90.8, 96.3 and 95.9%, respectively. SEM and AFM micrographs demonstrated that the epoxy prepolymer could effectively block the acid attack by chemisorption on the surface of the carbon steel, the high correlation coefficient and low Standard Deviation (SD) and low Sum of Squares (SS) value gave the best fit for Langmuir isotherm. PDP data suggested that the epoxy prepolymer could provide excellent corrosion performance and showed a mixed-type inhibitor with predominant cathodic effectiveness. Investigate of the inhibitory layer and the potential mechanism was conceptually evaluated using DFT, MD simulations, radial distribution function (RDF) and mean square displacement (MSD).

Development rheological and anti-corrosion property of epoxy polymer and its composite.

Epoxy polymer, namely, decaglycidyl pentamethylene dianiline of phosphorus (DGPMDAP) was synthesized in three steps. The synthesis of epoxy polymer DGPMDAP was investigated by nuclear magnetic resonance spectroscopy, rheological analysis, scanning electron microscope (SEM), stationary and transient electrochemical methods (PDP and EIS), respectively. The rheological properties of composite (DGPMDAP/MDA/TiO2) without and with different percentages of titanium dioxide (0%, 5%, 10% and 15%) increase with both the increase in frequency and with rate of load of titanium dioxide. Besides, SEM micrographs shows a good dispersion of the titanium dioxide charge in the composite (DGPMDAP/MDA/TiO2) elaborated. The results of PDP show that epoxy polymer DGPMDAP acts as mixed type inhibitor and reaches maximum corrosion inhibition efficiency reaches 92 % at 10-3 M. Besides, EIS results indicate that DGPMDAP act as good inhibitor for carbon steel in 1 M HCl solution and its efficiency reaches 91 % at 10-3 M of DGPMDAP. Furthermore, the adsorption of DGPMDAP on carbon steel surface obeyed Langmuir isotherm.

Textile finishing dyes and their impact on aquatic environs.

In the present review, we have been able to describe the different families of dyes and pigments used in textile finishing processes (Yarns, fabrics, nonwovens, knits and rugs) such as dyeing and printing. These dyes are reactive, direct, dispersed, indigo, sulphur and vats. Such that their presence in the liquid effluents resulting from the textile washing constitutes a serious risk, in the absence of their purification, for the quality of receiving aquatic environments. Indeed, the presence of these dyes and pigments can cause a significant alteration in the ecological conditions of the aquatic fauna and flora, because of the lack of their biodegradability. This has a negative impact on the equilibrium of the aquatic environment by causing serious dangers, namely the obvious dangers (Eutrophication, under-oxygenation, color, turbidity and odor), the long-term dangers (Persistence, bioaccumulation of carcinogenic aromatic products and formation of by-products of chlorination), mutagenicity and carcinogenicity.