Self-healing Ability of Epoxy Vitrimer Nanocomposites Containing Bio-Based Curing Agents and Carbon Nanotubes for Corrosion Protection

Abstract

Epoxy is extensively used for anti-corrosion coatings on metallic materials. Conventional epoxy coatings have a permanent crosslink network that is unable to repair itself when cracks and damages occur on the coating layer. This study aims to develop self-healing epoxy vitrimer/carbon nanotube (CNTs) nanocomposite for coating. Two bio-based curing agents viz., cashew nut shell liquid (CNSL) and citric acid (CA) were employed to create covalent adaptable networks. The 0-0.5 wt% CNTs were also incorporated into epoxy/CNSL/CA matrix (V-CNT0-0.5). Based on the results of our study, thermomechanical properties of V-CNT nanocomposites increased with increasing CNTs content. The bond exchange reaction of esteri cation was thermally activated by near infrared (NIR) light. The V-CNT0.5 showed the highest self-healing e ciency in Shore D hardness of 97.37%. The corrosion resistance of coated steel with V-CNT0 and V-CNT0.5 were observed after immersing the samples in 3.5 wt% NaCl for 7 days. The corrosion rate of coated steel with V-CNT0.5 decreased from 9.53 x 10 2 MPY to 3.12 x 10 -5 MPY whereas an increase in protection e ciency of 99.99% was observed. By taking advantages of the superior self-healing and anti-corrosion properties, V-CNT0.5 could prove to be a desirable organic anti-corrosion coating material.

Green-synthesized silver nanoparticle coating on paper for antibacterial and antiviral applications

“…The use of nanotechnology to create nanomaterials has been quite common in coating applications because of the high surface area of nanoparticles with regard to their volume, low utilization of chemical agents, and less consumption of energy [ 8 , 9 ]. Among available nanomaterials, silver nanoparticles (AgNPs) are widely used because of their outstanding properties such as antimicrobial activities [ 10 , 11 ] and less toxicity for mammalian cells [ 12 , 13 ].…”

Stress Relaxation Behavior and Electrically Activated Dynamic Exchange in Carbon Nanotube-Modified Epoxy Vitrimers

“…Thus, the alteration of the stress relaxation behavior of the nanomodified dynamic vitrimers should be linked to changes of the chemical and/or physical interactions of the cross-link network and of the dynamic bonds upon the addition of CNTs. As discussed previously, the addition of fillers influences the stress relaxation of vitrimers because fillers could be linked with the vitrimer matrix and participate in the bond exchange reactions. , The level of surface functionality of nanofillers determines their participation in the exchange reaction, for instance, through their hydroxyl or amine groups . It has been shown recently that the hydroxyl group concentration in the networks dictated the rate of bond exchange in polycarbonate vitrimers .…”

“…As discussed previously, the addition of fillers influences the stress relaxation of vitrimers because fillers could be linked with the vitrimer matrix and participate in the bond exchange reactions. 37,38 The level of surface functionality of nanofillers determines their participation in the exchange reaction, for instance, through their hydroxyl or amine groups. 39 It has been shown recently that the hydroxyl group concentration in the networks dictated the rate of bond exchange in polycarbonate vitrimers.…”

Recyclable and Self-Repairable Epoxy Anticorrosion Coatings with Curing-Controlled Thermoplasticity

“…Kasemsiri et al developed a series of anticorrosion coatings based on a catalyst-free epoxy vitrimer cured by cashew nut shell liquid and citric acid. After being blended with carbon nanotubes (CNTs), the coatings could be repaired under the near-infrared (NIR) irradiation once damaged . Saed et al fabricated an epoxy-based virtimer-like coating with self-healing ability by incorporating cellulose-functionalized halloysite nanotubes .…”