Study the Effect of the Untreated and Treated Fly Ash on the Mechanical Properties of the Polymer Composites Based on a Mixture of Bisphenol a and Bisphenol F Epoxy Resin Cured by Kingcure K11 Hardener Journal title: International Journal of Trend in Scientific Research and Development Authors: Bach Trong Phuc | Pham Duc Trinh | Nguyen Thanh Liem Subject(s): Biological Sciences, Computer and Information Science, Engineering, Mathematics, Agricultural Engineering, Management, Engineering, Multidisciplinary