Preparation and Comprehensive Protective Performance Study of Thickened Magnolol Epoxy Resin Coatings

Abstract

The biomass raw material magnolol with a biphenyl structure was used to synthesize bio-based epoxy resin, and flexible polyetheramine curing agents(D230, D400, D2000 and T403) were used to cure the bio-based epoxy anti-erosion coating. The effects of polyetheramine molecular weight and functionality on the mechanical properties, corrosion resistance and anti-erosion protection performance of magnolol epoxy resin were explored, and the anti-erosion mechanism of magnolol epoxy coatings was proposed. Results showed that the magnolol epoxy coating cured with D230 maintained a high impedance value(1.25×1011 Ω·cm2) after 15 d of immersion in 3.5%(mass fraction) NaCl solution. The coating cured with T403 possessed a high tensile strength(26.59 MPa), low friction coefficient(0.373) and wear rate [0.018 3 mm3/(N·m)], while the magnolol epoxy coating cured with D2000 exhibited lower mass loss(244.74 mg) and volume loss(157 mm3) in the erosion test. Under the coupled erosion of solid/liquid/gas three-phase flow, the longer flexible segment of D2000 endowed the magnolol epoxy coating with better elasticity and flexibility, and therefore reduced the impact of the erosion medium, thus showing excellent anti-erosion performance.

Keywords

• thickened magnolol epoxy resin; polyether amine curing agents; mechanical properties; anti-erosion protection performance