Formulating flexible epoxy novolac coatings with cardanol-based flexibilisers
Monday, 20 March 2017
Indian researchers from National Chemical Laboratory have developed flexible epoxy novolac coatings with two different cardanol-based flexibilisers that show great potential in industrial applications.
The coatings were developed by reacting an epoxy novolac resin, poly[(phenylglycidyl ether)-co-formaldehyde] (PPGEF) with an amine curing agent, 4,4′-diamino-3,3′-dimethyldicyclohexyl methane (BMCHA), cardanol based reactive diluent (Cardolite NC-513) and two different cardanol-based flexibilisers (Cardolite NC-514 and Cardolite NC-547). The flexibiliser content was varied from 5 to 10% by weight of the resin.
Coated onto stainless steel panels
The coatings were coated onto stainless steel panels and tested for gloss, cross-hatch adhesion, falling weight impact resistance, flexibility, abrasion, scratch hardness, solvent scrub resistance, and chemical resistance. The thermo-mechanical properties were determined by TGA, DSC, DMTA, and tensile strength measurements. The cryofractured specimens were subjected to SEM analysis. The influence of structural differences of the two flexibilisers on the coating properties was investigated.
The study is published in: Journal of Applied Polymer Science, Volume 134, Issue 23, 15 June 2017