Corrosion Resistance of Epoxy Coatings Modified by Bis-Silane Prepolymer on Aluminum Alloy

Abstract

In this communication, a bis-silane prepolymer was used to modify epoxy resin, aiming to enhance the corrosion resistance of epoxy coatings on aluminum alloy substrates. The bis-silane prepolymer was prepared by tetraethoxysilane (TEOS) and γ-glycidoxypropyl trimethoxysilane (GPTMS). The corrosion behavior of silane-epoxy coatings was studied. Compared with silane monomer-modified epoxy coatings, bis-silane-modified epoxy coatings have lower coating capacitance (Cc), higher charge transfer resistances (Rdl), and lower double layer capacitance (Cdl) during long-time immersion. It indicates that bis-silane-modified epoxy coating has stronger waterproof permeability and substrate corrosion protection ability. In addition, due to the leaching of the silane component and cross-linking reaction between different silanes during the immersion process, the bis-silane-modified epoxy coatings exhibit much stronger “self-healing” ability.

Effect of Water Uptake, Adhesion and Anti-Corrosion Performance for Silicone-Epoxy Coatings Treated with GLYMO on 2024 Al-Alloy

“…The introduced Model D (i.e., Figure 6 d) contains the diffusion impedance, which includes the diffusion capacitance ( ) and the diffusion resistance ( ). This diffusion behaviour is not the ideal Warburg impedance, resulting in dispersion coefficient n deviating from 0.5 [ 26 , 27 , 28 , 29 , 30 ].…”

“…Considering the system’s non-ideal capacitance characteristics, a constant phase element (CPE) is used to replace all capacitors in EECs to obtain a more accurate fitting result. The impedance of CPE is defined as follows [ 10 , 25 , 26 , 27 , 28 , 29 ]: where is the CPE-constant with the units of , the imaginary number, n the CPE-power ( ), and is the angular frequency ( , is the frequency). The CPE is a pure capacitance for n = 1, in which the derivation of n from the unit is due to the dispersion effect.…”

“…Electrochemical impedance spectroscopy (EIS) is a well-known electrochemical technique used to evaluate the performance of organic coatings. It has proven to be a powerful tool for obtaining specific parameters of coating/metal systems [ 14 , 15 , 25 , 26 , 27 , 28 , 29 , 30 ]. The coating resistance, capacitance and other parameters obtained from the equivalent circuit (EECs) can quantitatively reflect the corrosion resistance of the coating.…”

Comparison of Two-Component Silyl-Terminated Polyether/Epoxy Resin Model and Complete Systems and Evaluation of Their Mechanical, Rheological and Adhesive Properties

“…Consequently, there is a need to perform research on the development of new silyl-modified polymers and perspective hybrid systems based on silyl-modified polymers. However, there is shortage of detailed scientific information on SIL/EP systems, except for some research publications and patents [17][18][19]. In our previous publications, we have described some issues of the development of SIL/EP model systems (the systems which consisted only from pre-polymers and catalysts) without and with compatibilizers.…”

Epoxyorganosilane Finishing Compositions for Fibrous Fillers of Thermosetting and Thermoplastic Binders

“…According to [ 40 , 41 , 42 , 43 , 44 ], the modification of epoxy resin with organosilanes is mostly applied to improve the elasticity and corrosion resistance of the coating. Investigations dedicated to the modification of epoxy resin with organosilanes to use the compositions as fiber finishes are rare, and are of significant interest.…”