Structure-Performance Relationships in Alkylene Oxide-Modified Epoxy Coatings

By Kenneth W. Anderson

Structure-performance relationships in advanced epoxy resins flexibilized with segments of polyalkylene oxide were studied in electrocoat formulations to determine the effects of alkylene oxide type, oxide block length, and total oxide loading on coating properties.

Corrosion resistance and flexibility/adhesion improve with the use of short oxide blocks and at the higher end of the oxide loading ranges studied, with propylene oxide being the preferred alkylene oxide. A two-stage procedure for copolymerization pro-vides further enhancement of corrosion resistance.

The structure-performance relationships found in this work are expected to apply to the use of similar resins in lower VOC waterborne, higher solids, and/or higher flow powder formulations.