摘要

Organic-inorganic hybrid coatings of crosslinked epoxy and thiol silicates (TGST) were synthesized for the corrosion protection of low carbon steel via a waterborne sol-gel route. The coatings were synthesized in two stages; in the first step two separate aqueous formulations of epoxy and thiol decorated silica colloids were prepared and subsequently crosslinked in a 1:1 ratio in the second stage. The structure and rate of crosslinking was monitored using Raman spectroscopy. Formulation stability was measured based on viscosity changes and pot-life assessment. The novel material was characterized for its particle size using dynamic light scattering. Viscosity average molecular weight was calculated using Fikentscher's equation and using polyethylene oxide molecular weights as a calibration standard. The covalently bonded epoxy-thiol silicate thin-film coating was uniform and defect free. Accelerated corrosion resistance was tested by exposing the panels to standard salt solution tests. TGST showed a 96% improvement in corrosion inhibition over the non-crosslinked formulations in a corrosive environment. The synthesis and characterization of TGST using a simple approach, revealed key synthetic parameters for generating optimized sol-gel corrosion prevention materials.
[GRAPHICS]
Crosslinked epoxy-thiol decorated silicate coatings for corrosion prevention were synthesized.
Green, non-toxic formulations were prepared via a waterborne sol-gel route at room temperature.
Enhanced barrier properties showing 96% improved corrosion resistance of crosslinked coatings over the non-crosslinked formulations on low carbon steel were achieved.
Coatings were smooth, defect-free, and showed easy applicability to suit dip or spray coating.
The two-component coating system showed a commercially attractive pot-life.

  • 出版日期2018-8