Fluorosilane emulsifying chlortrifluoroethylene ternary copolymerization design towards strong adhesion, anti-corrosion, fluorescent waterborne fluorocarbon coatings for tinplate substrate

Abstract

Waterborne fluorinated ethylene and vinyl ether copolymer (FEVE) coatings are progressively replacing solvent-based FEVE coatings because of their environmental friendliness. However, their practical application is limited due to the poor adhesion, waterproofing, and corrosion resistance, as well as the environmentally unfriendly nature of the small emulsifiers used. Here, a novel waterborne FEVE coating with excellent adhesion, anti-corrosion, and fluorescent properties was developed using amphiphilic fluorosilane oligomer (PFSQ) as microreactors and chlorotrifluoroethylene (CTFE), isobutyl vinyl ether (IBVE), and glycidyl methacrylate (GMA) as copolymer monomers. The introduction of fluorosilane significantly enhances the hydrophobicity of the coating (the water contact angle increased from 69.3 ± 2.4° to 131.4 ± 1.1°). The epoxy groups in the GMA units of terpolymer facilitate bonding of the coating to the substrate, enhancing the adhesion of the coating to the tinplate substrate (the lap shear strength increased from 0.47 ± 0.04 to 0.92 ± 0.01 MPa). Moreover, the interaction between the epoxy groups of GMA and the silicon hydroxyl groups of PFSQ in the synergistic network leads to the intrinsic luminescence of the coating. In addition, the coating exhibits superior corrosion resistance. The molecular structure design provides a new idea for the development of multifunctional waterborne FEVE coating.