Amine terminated poly(ethylene glycol) benzoate modified epoxy networks

Purpose - To evaluate the efficiency of modifying epoxy resin using amine terminated poly(ethylene glycol) benzoate (ATPEGB) for improved toughness and to optimise the results of such a modification. Design/methodology/approach - For effective toughening, various compositions were made by incorporating different concentrations of ATPEGB. The impact and adhesive strengths of the unmodified and modified epoxy networks were characterised. Findings - The modification of epoxy resin using ATPEGB showed significant enhancement of impact and adhesive strengths over the unmodified one. The modification caused a chemical linkage between ATPEGB and resin which led not only to a phase separation but also to ensuring the intrinsically strong chemical bonds across the ATPEGB phase/resin matrix interface, which was the main cause to the improved impact and adhesive strengths. The optimum results were obtained at 12.5 phr (parts per hundred parts of epoxy resin) of modifier. Research limitations/implications - The modifier, ATPEGB, used in the present context was synthesised from poly(ethylene glycol) (PEG) of molecular weight 600. Besides, it could be synthesised from PEG of molecular weight 200, 400, 4,000, 20,000 etc. In addition, the efficiency of modification of epoxy resin using these could also be studied. Practical implications - The method developed provided a simple and practical solution to improving the toughness of cured epoxy. Originality/value - The method for enhanced toughness of cured epoxy was novel and could find numerous applications in surface coating and adhesive.