Polyaniline coated core-shell polyacrylates: Control of film formation and coating application for corrosion protection

• Published in: Progress in organic coatings Vol. 128; pp. 40 - 51
• Main Authors: Bertuoli, Paula T., Baldissera, Alessandra F., Zattera, Ademir J., Ferreira, Carlos A., Alemán, Carlos, Armelin, Elaine
• Format: Journal Article Publication
• Language: English
• Published: Lausanne Elsevier B.V 01-03-2019; Elsevier BV
• Subjects: Acrylic acid; Acrylic polymer; Acrylic resins; Acrylics; Adhesion tests; Aniline; Carbon steels; Contact angle; Core-shell; Core-shell Acrylic polymer Polyaniline X-ray photoelectron spectroscopy Corrosion; Corrosion; Corrosion prevention; Corrosió i anticorrosius; Emulsion polymerization; Enginyeria química; Espectroscòpia de fotoelectrons emesos per raigs X; Fourier transforms; Free radical polymerization; Free radicals; Image transmission; Light scattering; Mechanical properties; Microscopy; Nanoparticles; Optical properties; Organic chemistry; Phosphating (coating); Photoelectrons; Polyaniline; Polyanilines; Polymerization; Polymers; Polímers; Protective coatings; Scanning electron microscopy; Submerging; Thermogravimetry; Transmission electron microscopy; X-ray photoelectron spectroscopy; Àrees temàtiques de la UPC; Acrylic polymer; Corrosion; Polyaniline; Core-shell; X-ray photoelectron spectroscopy
• ISSN: 0300-9440; 1873-331X
• DOI: 10.1016/j.porgcoat.2018.12.007

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•Ease latex nanoparticles obtaining and ease control of PAni-DBSA shell thickness.•Free acrylic films with semiconducting properties and based in environmentally friendly waterborne formulations.•Acrylic coating with barrier and passivating properties after the addition of only 3 wt. % of PAni-DBSA conducting polymer.•The very low PAni-DBSA content does not alter the main physical-chemical properties of the pristine polymer.
Aqueous polymer colloidal nanoparticles, composed by poly(methyl metacrylate), butyl acrylate, and acrylic acid, as “core” (P(MMA/BA/AA)); and polyaniline (PAni) doped with dodecylbenzenesulfonic acid (DBSA), as “shell”, were prepared. The complete synthesis consisted of two-steps. In the first step P(MMA/BA/AA) particles were obtained in a semi-continuous process by free radical emulsion polymerization, followed by a second step where the chemical oxidative polymerization of aniline monomers upper the “core” surfaces occurred. Transmission electron microscopy images (TEM) and dinamic light scattering (DLS) confirmed the obtaining of spherical nanoparticles, which are stable for further free solid film preparation and coatings for metal protection. The free films were characterized by FTIR, Raman, UV–vis, X-Ray photoelectron spectroscopy (XPS), differential scanning calorimetry (DSC), thermogravimetry (TGA), optical and scanning electron microscopy (SEM), static contact angle, mechanical properties and water absorption. The metal protection was evaluated after check the adhesion properties and the impedance parameters. The presence of a low concentration of PAni-DBSA (3 wt. %) on the acrylic polymer altered the hydrophilicity and the water uptake properties of the coatings without affecting the capability of obtaining passive layers for the protection of phosphatized carbon steel surface against corrosion, even after almost 20 days of immersion in NaCl aggressive solutions.