| Polydimethylsiloxane (PDMS) was used as an ideal modifier in epoxy resin because of its low surface energy, excellent flexibility and thermal stability. PS-b-PDMS-b-PS is a new type of thermoplastic elastomers with excellent mechanical properties and surface properties. There is good miscibility between PS chain segment in PS-b-PDMS-b-PS and epoxy resin, so PS chain segment can improve the dispersion of PS-b-PDMS-b-PS in the matrix of epoxy resin.In this paper, PS-b-PDMS-b-PS was synthesized by coupling reaction under high purity argon, using dimethyldichlorosilane as coupling agent, n-Butyllithium as initiator, cyclohexane as solvent, tetrahydrofuran as polar additive.A solvent epoxy varnish was prepared by using E-44 epoxy resin, T-31 curing agent and dimethylbenzene/cyclohexanone mixture solvent. Increasing PS-b-PDMS-b-PS content in the modified epoxy coatings, water contact angles increased and the surface enegy values were decreased. It was also found that the flexibility of the modified epoxy coatings was improved remarkbly with the increasing of PS-b-PDMS-b-PS content. The contact angle, the water absorption, the flexibility, the pencil hardness and the adhesion force of the modified epoxy coatings with 10% PS-b-PDMS-b-PS content reached up to 114.2°, 0.060%, 0.5mm, 3H and 1 level respectively.The anticorrosion property of the modified coating was improved due to the addition of PS-b-PDMS-b-PS by accelerating corrosion test.A solventless epoxy varnish was prepared by using E-51 epoxy resin, R(B) curing agent and XY501B-3 reactive diluent. Compared to the contact angle of the unmodified coating, the contact angle of the modified epoxy coating with 1% PS-b-PDMS-b-PS content increased to 105.3°. And other properties of the modified solventless epoxy varnish coating were still very well.A modified epoxy colored paint was prepared by blending epoxy anti-corrosion coating 1 and PS-b-PDMS-b-PS. It was found that the contact angle of the modified epoxy coating with 10% PS-b-PDMS-b-PS content increased to 113.6°, and the surface enegy decreased by 19.34 mN·m-1, compared to the unmodified coating. The water absorption decreased significantly with the increasing of PS-b-PDMS-b-PS content. With 10% PS-b-PDMS-b-PS content, the water absorption, the pencil hardness and the adhesion force of the modified epoxy paint were 0.064%, 2H and 1 level, respectively. Accelerating corrosion test showed anticorrosion property of the modified coating was improved.Blending epoxy anti-corrosion coating 2 and PS-b-PDMS-b-PS, the result indicated that the hydrophobic properties of the modified epoxy anti-corrosion coating 2 were improved dramatically, and other properties were still very well. With 4% PS-b-PDMS-b-PS content, the contact angle, the pencil hardness and the adhesion force were respectively 107.3°, 2H and 1 level.
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