Owing to their good corrosion performance

chemical resistance and adhesion to metallic substrates

as well as low shrinkage upon cure

epoxy resins (EPRs) have found an extensive application in anticorrosive coatings. Silicone- resin (SR) gels or chain-segments of good hydrophobicity have been introduced to cured EPR coating systems as EPR-filler coupling layers

primers of metallic substrates

dispersed or interpenetrating-polymer-network phases

copolymerizing component

etc.

via hydrolysis and condensation of organosilanes and/or addition-reaction to the EPRs of linear polysiloxanes or the organosilanes

to improve the corrosion performance of the modified EPR coatings through both the hydrophobic barrier and the gel-phase or cross-link (i. e.

cross-linking chain-segment) corrosion-inhibition mechanisms; the SR volume fraction also effects both enhancements of the aging and heat resistance of the coatings. The anticorrosive performance of cured EPR coatings is increased as well upon grafting

prior to cure

of organosilane small-molecules onto the EPR backbones via alcoholysis (i. e.

condensation) reaction under anhydrous catalysis between the alkoxyls of the former and the hydroxyls of the latter

due to the presence of water-digestion barrier during the service time of the coatings through hydrolysis of the unreacted alkoxy groups of the organosilane grafts. For SR-modified EPR coatings

a moderate content of ceramic (nano-oxide

clay

carbon

etc. ) fillers added may result in unique resin-ceramic two-phase morphology that produces structural hydrophobicity

inorganic-acid-salt ( chromate

phosphate

silicate

rare-earth-cerium-salt

molybdate

permanganate

etc. ) or organic-compound (8-hydroxyquinoline

chloranil

etc. ) conversion-coatings or - particles incorporated may function at resin-coating-metal interfaces as electrochemical convertive protection

and lower- electrode-potential

active metal (Mg

Zn

etc. ) powders loaded may serve at metallic-substrate surfaces as electrochemical cathodic protection; meanwhile

each of the three types of fillers added may further increase the corrosion-inhibition effect of the resin coatings. Tailoring and optimization of the structure and morphology of EPR-SR systems

synergistically coupled by incorporation of one or more modifying fillers

has become one of the necessary approaches to the corrosion- performance maximization of SR-modified EPR coatings.