Epoxy resins: Effect of extent of mixing on properties

Inhomogeneities observed in cured epoxy resins by several workers appear to be related to the effectiveness of mixing the reactants. This mixing effectiveness also has an effect on the softening temperature Tg, of DETA cured resins, of as much as 10°C. Improved mixing of both DETA and Versamid 140 cured systems resulted in substantial ultimate strength improvement, in agreement with other recent results. Samples were mixed by hand, by a concentric cylinder mechanical mixer, and by application of an electrical filed between the cylinders of the mechanical mixer while mechanical mixing was in progress.