The Use of Complex Additives for the Formation of Corrosion- and Wear-Resistant Epoxy Composites

Hindawi Advances in Materials Science and Engineering Volume 2019, Article ID 8183761, 5 pages https://doi.org/10.1155/2019/8183761 Research Article The Use of Complex Additives for the Formation of Corrosion- and Wear-Resistant Epoxy Composites Andriy Buketov ,1 Oleksandr Sapronov ,1 Mykola Brailo ,1 Danylo Stukhlyak,2 Serhii Yakushchenko ,1 Natalia Buketova ,1 Anna Sapronova ,1 and Vitalii Sotsenko 1 1 2 Department of Transport Technologies, Kherson State Maritime Academy, 20 Ushakova Ave., Kherson 73000, Ukraine Department of Computer Integrated Technologies, Ternopil Ivan Puluj National Technical University, 56, Ruska Str., Ternopil 46001, Ukraine Correspondence should be addressed to Serhii Yakushchenko; Received 18 February 2019; Accepted 3 June 2019; Published 20 August 2019 Academic Editor: Guoqiang Xie Copyright © 2019 Andriy Buketov et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The corrosion resistance and hydroabrasive resistance of the developed epoxy composite coatings are investigated in this paper. The analysis of the penetration index change after τ � 50–150 days of immersion in a water medium and 10% sulfuric acid solution is carried out. The optimal ratio of the modifier and nanodispersed (Si3N4, Al2O3, AlN, and TiN) and fibrous (viscose, polyamide, matka silk, rong, and cashmere) fillers in the epoxy binder is determined. It was allowed to slow down the process of electrochemical reaction on the metal surface. The penetration of aggressive media in such a coating during the time t � 150 days is 0.8–2.8%. It is 1.5–2 times lower than the similar indexes of the initial epoxy matrix. The rational combination of the fibrous filler (wool, acrylic PAN, and cashmere), modifier, and nanodispersed (Si3N4, AlF3, IH, and ZrH) filler in the epoxy binder is found, which allows to provide optimum indexes of wear rate. The wear rate under the action of a hydroabrasive of such a coating is I � 0.20%, which is 4 times lower than the similar indexes of the initial epoxy matrix. The wear mechanism of such coatings is caused by the physical and mechanical processes of microcutting and plastic deformation of the surface layer of the material. 1. Introduction Improvement in operational characteristics of technological equipment, which is used in various branches of industries, is possible by applying plasma, eutectic, and epoxy coatings [1–8]. At the same time, the introduction of additives in the epoxy binder improves the technological properties of polymers and also significantly affects the physical and mechanical properties, anticorrosion properties, and wear resistance of the equipment. Therefore, a rational combination of components in the epoxy binder will provide the necessary complex of the protective coatings properties in specific operational conditions [6–11]. The analysis of works [6–18] allows to state that epoxy composites are characterized by chemical stability and wear resistance in different operational conditions, wherein the adhesive strength of the polymers to the base and the cohesive strength of the material are main criteria that provide protective properties for a long time of operation. As it is known, acid solutions are the most aggressive medium for epoxy composites. Therefore, it is important from a scientific and practical point of view to develop new materials that can maintain their properties in different operating conditions. The aim of the work is to investigate the corrosion resistance and wear resistance of the developed epoxy composites. 2. Materials and Methods For the formation of epoxy composite materials (CM), as the main component of the binder, the epoxy diane oligomer ED-20 was used, which is characterized by high adhesion 2 and cohesive resistance, slight shrinkage capacity, and processability when applied on the surface of a complex profile. 2,4-Diaminotoluene (DAT) is used as a modifier. According to the results of previous studies, the modifier is added into a binder at the content of 1.00°pts. wt. per 100°pts. wt. of epoxy oligomer ED-20. The molecular formula of the modifier is C7H10N2. The molecular weight of DAT is 122.17 g/mol. The melting point is 98°C. The modifier is soluble in polar organic solvents (methanol, ethanol, acetone, and ethyl acetate) and is insoluble in water. Powders that are a mixture of nanodispersed compounds (MNDC) are used as nanodispersed fillers for experimental studies. They are as follows: Si3N4, Al2O3, AlN, and TiN (MNDC 1) with the dispersion d � 20–80 nm and Si3N4, AlF3, IH, and ZrH (MNDC 2) with the dispersion d � 30–40 nm. In addition, a mixture of discrete fibers (MDF) is used: MDF 1 (viscose, 37%; polyamide, 23%; matka silk, 18%; rong, 18%; cashmere, 4%) with parameters l � 0.5–1.0 mm and d � 18–25 μm and MDF 2 (wool, 60%; polyacrylonitrile (PAN), 30%; cashmere, 10%) with parameters l � 0.5–1.0 mm and d � 18–25 μm. Polyethylene polyamine (PEPA) curing agent, which allows to solidify the materials at room temperature, was used for cross-linking of epoxy compositions. PEPA is a lowmolecular-weight substance, which consists of the following interconnected components: [-CH2-CH2-NH-]n. To crosslink CM, the curing agent was added to the composition at the stoichiometric ratio of components (parts by weight): ED-20 : PEPA � 100 : 10. The epoxy composite, filled with particles of disperse filler, was formed using the following technique: preliminary dosage of ED-20 epoxy diane resin, heating the resin to a temperature of T � 80 ± 2°C, and its exposition at a temperature over time τ � 20 ± 0.1 min; dosage of disperse filler and its subsequent introduction into an epoxy binder; hydrodynamic combination of the oligomer ED20 + DAT + MNDC during the time τ � 10 ± 0.1 min; introduction of MDF; ultrasonic processing (USP) of the composition (epoxy binder, modifier, nanoparticles, and fibers) during the time τ U � 1.5 ± 0.1 min; cooling the composition to room temperature during the time τ � 60 ± 5 min; introduction of PEPA curing agent; and mixing of the composition over time τ � 5 ± 0.1 min. Subsequently, the CMs were solidified according to the following conditions: the formation of specimens and their exposition over time t � 12.0 ± 0.1 h at a temperature T � 20 ± 2°C, heating at a speed of υ � 3°C/min to a temperature T �120 ± 2°C, exposition of the specimens at a given temperature during the time t � 2.0 ± 0.05 h, and slowly cooling to a temperature T � 20 ± 2°C. In order to stabilize the structural processes in the matrix, the specimens were kept during time t � 24 h in air at a temperature T � 20 ± 2°C, followed by conducting experimental tests. The following properties of CM were studied: adhesion strength at break, elastic modulus and fracture stresses Advances in Materials Science and Engineering during the flexion, impact strength, (...truncated)