Improvement of the Protective Properties of Alkyd Coatings by Nanosized Phosphate Pigments

Abstract

UDC 620.193 Zinc phosphate nanoparticles with a thickness of ∼ 20 nm are synthesized by an ion-exchange reaction. We study the influence of the nature of reaction media and modifiers of the surface on their shapes and sizes. It is shown that acryl monomers are optimal modifiers of the surface. We investigate the anticorrosion activity of synthesized nanosized zinc phosphate in alkyd coatings on aluminum alloys by the method of electrochemical impedance spectroscopy. It is shown that nanosized zinc phosphate has better inhibiting properties than modified phosphate pigments and can be used in paint primer coatings.Corrosion-resistant paint coatings are extensively used for the protection of metallic structures against atmospheric corrosion. The primer layer containing inhibiting pigments plays the principal protective role in the composition of paint coatings formed on the metals. In this aspect, chromates prove to be especially efficient. However, they are extremely toxic and ecologically dangerous. At the same time, zinc phosphate is a wellknown nontoxic pigment [1, 2]. However, its anticorrosion efficiency is insufficient, especially in the initial stages of development of underfilm corrosion of the metal. This is explained by the low solubility of zinc phosphate in aqueous media. It was shown [3] that the corrosion resistance of primer paint coatings on aluminum alloys and galvanized steel increases as a result of the addition of micronized zinc phosphate instead of the phosphate pigment. This is probably caused by an increase in its specific surface area, inversely proportional to the size of particles of the pigment [4]. The anticorrosion activity of zinc phosphate in paint coatings can be increased by decreasing its particle sizes down to the nanorange. The methods used for the preparation of nanosized zinc phosphates were described in [5][6][7]. However, all these methods are power-consuming, technically complicated, and therefore, poorly applicable in the industry. The aim of the present work is to get nanosized zinc phosphate by using the improved procedures and study the influence of the conditions of synthesis on its size, shape, and anticorrosion properties. Materials and Methods for InvestigationsSynthesis of Nanozized Zinc Phosphate. We synthesized zinc phosphate in a glass reactor equipped with a mechanical stirrer at 20°С by an ion-exchange reaction in aqueous media. To modify the surface of obtained

Alkyl phosphonium‐based ionic liquids as promising additives for the corrosion protection of epoxy coatings in saline medium: Effect of the anion

“…All other results obtained with increased immersion time and those corresponding to the other systems presented two‐time constant and were modeled by a two‐time constant equivalent circuit. The addition of IL to the system caused an increase in the total resistance ( R T = R coat + R ct ) after several analyzed times, indicating an improvement in the anticorrosive property 50 . After the immersion time corresponding to 24 h, the systems loaded with 0.5 phr of [P 66614 ] 2 [ZnCl 4 ] and 0.5 and 1 phr of P 4442 [dep] displayed significantly higher R coat values than the neat ER coating, suggesting improved barrier properties.…”

“…The addition of IL to the system caused an increase in the total resistance (R T = R coat + R ct ) after several analyzed times, indicating an improvement in the anticorrosive property. 50 After the immersion time corresponding to 24 h, the systems loaded with 0.…”

Recent Progress in Synthesis and Applications of Zinc Phosphate Nanoparticles: A Review

“…The anticorrosion efficiency of nano-sized ZnP in primer paint coating was somehow inadequate due to its low solubility in water. However, surface modification of NPs with acrylate monomers (e.g., butyl acrylate and butyl methacrylate) helped to overcome the situation [104]. Electrochemical impedance spectroscopic (EIS) studies revealed that alkyd coated nano-sized ZnP exhibited better corrosion inhibition performance than commercially available inhibiting phosphate pigment.…”

Optimization of Parameters for Protection of Materials by Primer Application

“…The values of the anticorrosive pigment content previously studied by some authors ranged from 2.6% [16], 3.5% [17], 5% [18], and 6% [19] up to 10% [20], and those values were used in this experiment as a basis for the determination of the same input variable. The values of the dry film thickness reported in published studies ranged from 60 ± 6 µm [21], 100 ± 25 µm [13], 120 µm [22], 130 ± 5 µm [23], and 170 ± 10 µm [18] up to 190 µm [9]. Conditioning time, which defines the time interval required to achieve good cohesion force within the coating itself, as well as good adhesion force between the coating and the substrate material, also varied in previous studies.…”