Radical induced cationic frontal polymerization for preparation of epoxy composites

Epoxy composites are usually prepared from two component formulations that have limited storage stability and require time and energy consuming post curing. Radical induced cationic frontal polymerization (RICFP) circumvents these drawbacks and allows the fast on demand curing of these materials. In this study, the most suitable reactive diluents for preparing composites based on highly viscous bisphenol-A-diglycidylether were identified. The results revealed that 1,6-hexanediol diglycidylether (HDDGE) and (3-ethyloxetan-3-yl)methanol (EOM) were most effective reactive diluents regarding viscosity and reactivity. Composite production with various types of fillers were successfully evaluated regarding their frontal polymerization parameters. It was possible to show that high filler contents of up to e.g. 74 vol% glass microspheres and 40 vol% short carbon fibres were able to be processed. In comparison with thermal curing techniques, the epoxy-based fibre reinforced polymer composites prepared by RICFP showed similar values in tensile measurement, but the manufacturing process was facilitated significantly.