Epoxy resins are characterized by excellent properties such as chemical resistance, shape stability, hardness and heat resistance, but they present low flame resistance. In this work, the synthesized derivatives, namely hexacyclohexylamino-cyclotriphosphazene (HCACTP) and novel diaminotetracyclohexylamino-cyclotriphosphazene (DTCATP), were applied as curing agents for halogen-free flame retarding epoxy materials. The thermal properties and combustion behavior of the cured epoxy resins were investigated. The obtained results revealed that the application of both derivatives significantly increased flame resistance. The epoxy resins cured with HCACTP and DTCATP exhibited lower total heat release together with lower total smoke production compared to the epoxy materials based on conventional curing agents (dipropylenetriamine and ethylenediamine). Comparing both derivatives, the HCACTP-cured epoxy resin was found to provide a higher flame resistance. The designed novel class of epoxy materials may be used for the preparation of materials with improved flame resistance properties in terms of flame spreading and smoke inhibition.

Department of Chemistry Faculty of Science Masaryk University Kotlarska 267 2 611 37 Brno Czech Republic

Fire Research Institute Ministry of Interior of the Slovak Republic Roznavska 11 83 104 Bratislava Slovakia

Institute of Chemistry and Technology of Macromolecular Materials Faculty of Chemical Technology University of Pardubice Studentska 573 532 10 Pardubice Czech Republic

Institute of Theoretical and Applied Mechanics of the Czech Academy of Sciences Centre Telc Prosecka 809 76 190 00 Prague Czech Republic

The Institute of Technology and Business in Ceske Budejovice Okruzni 517 10 370 01 Ceske Budejovice Czech Republic

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