Polyaniline emulsion as a passivator in styrene-acrylate waterborne coatings for the protection of carbon steel against corrosion

Abstract

T HE passivation effect of polyaniline (PANI) was utilized to enhance the protection efficiency of styrene-acrylate waterborne coatings against corrosion of carbon steel (CS). Styrene-acrylate emulsion (SACE) based on poly (styrene-co-butyl acrylate) was synthesized via a semi-batch emulsion polymerization while the PANI emulsion (PANE) was prepared by chemical oxidative polymerization of aniline in the micelles of sodium dodecyl benzene sulfonate. The coating formulations (Fs) were prepared by adding PANE to SACE at different weight solid ratios. The viscosity, density, solid content, particle size distribution, the shape of the particles, and stability of the blended emulsions were studied. The properties of the coatedfilms were evaluated such as hardness, impact resistance, flexibility, adhesion to the steel, glass transition temperature (Tg), and surface morphology. The effect of PANE in enhancing the protection efficiency of SACE film against corrosion of CS was estimated by visual corrosion test, weight loss measurements, and electrochemical Tafel polarization. The results showed an increase in the Tg from 23 o C for pure SACE film up to 36 o C for the film containing the maximum PANI content. SACE film loaded with 0.75% and 1% PANI exhibited the least corrosion current density of 0.07 and 0.11 µA/cm 2 , respectively. The formation of a passive layer on the coated-CS was recorded by the shift of corrosion potential for steel to the anodic direction.

Styrene/acrylate copolymer emulsions as strengthening agents for kraft bagasse pulp: A way for enhancing the mechanical properties of paper

“…Two types of styrene–acrylate copolymer emulsions were prepared, one of which was of a soft matrix (soft‐segmented poly(styrene‐ n ‐butyl acrylate) [S‐PSA]) and the other of a hard matrix (hard‐segmented poly(styrene‐ n ‐butyl acrylate) [H‐PSA]). The following successive steps 11,12 were used to prepare the copolymer emulsions by semicontinuous seeded emulsion polymerization: Pre‐emulsion process: In a beaker with a high‐speed Ultra‐Turrax homogenizer, 60 mL of distilled water, 6.96 g of Texapon N70, and a mixture of monomers comprising 86.5 g (0.675 mol) of n ‐butyl acrylate and either 64 g (0.614 mol) of styrene for S‐PSA or 85.9 g (0.825 mol) of styrene for H‐PSA, were added one at a time for 30 min at room temperature. Seeding process: Emulsion polymerization was done in a four‐necked round‐bottom flask with a nitrogen intake, a condenser, a mechanical stirrer, and a vacuum pump, and that was set up in a heating mantle. In a typical synthesis technique, the flask was filled with 96 mL of distilled water, 3.51 g of Tergitol NP30, 0.39 g of NaHCO 3 buffer, and 0.6 g of KPS.…”

Effect of Poly (aniline-co-o-toluidine) loaded on emulsion paints with different pigments on corrosion inhibition of mild steel

“…The absorption peak at 1573 cm-1 is assigned to the quinoid ring stretching. The peak observed at 1470 cm-1 corresponds to the presence of C=C stretching vibration in benzenoid ring [26,29,30]. The sharp peak at 815 cm-1 attributes the paracoupled phenyl ring in the copolymer.…”

“…Corrosion rate (CR) in millimeters per year (mm/y) was calculated from Faraday's law equation (2) [22,25,26] where K is a constant that defines the units of corrosion rate and equals to 3272 mm/y, EW is the equivalent weight in grams/equivalent, d is the density in g/cm3, A is sample area in cm2.…”

Effect of O2, N2, Ar, and Ar/O2 Plasma Treatment on Optical Properties of Polyaniline Films

“…The study of low-temperature plasma processing has been stimulated and excited by many current and potential applications. The demand for material quality and properties, and the increasing need for materials with new properties, are some of the factors that have given impetus to plasma induction and plasma-based technologies in the industry (1,2). Today, one possesses a whole gamut of industrial applications where the use of plasma-based technologies provides distinct advantages over other traditional technologies.…”