Epoxy adhesives for metal-polymer lap-joint applications
In a new work, epoxy formulations containing phenolic resin, recycled tire powder, and clay nanoplatelets were optimised based on L9 Taguchi experimental design approach.
The main effects of phenolic resin (X1 (wt.%), for thermal stability), recycled tire powder (X2 (wt.%), economically reasonable for toughening), and clay nanoplatelets (X3 (wt.%), for modulus enhancement) on mechanical properties of epoxy adhesives including tensile strength, Young’s modulus, and toughness, were studied by taking into account signal-to-noise ratio (S/N) as well as the analysis of variance (ANOVA).
Improvement of thermal stability
It was found that at X1 level of 50 wt.%, X2 level of 10 wt.%, and X3 level of 2 wt.% an increase of about 39% was observed in the single-lap shear strength compared to blank epoxy adhesive formulation. Scanning electron microscopy revealed crack mechanism in the form of deviation of crack growth pathway when encountered with large platy nanoclays. Thermal stability of epoxy was also improved by 16% based on degradation peak temperature monitoring.
The study is published in: Progress in Organic Coatings Volume 136, November 2019, 105291.
