LAUSR

Abstract The cyclotriphosphazene-based multi-functional epoxy resin hexa-[4-(glycidyloxymethyl)phenoxy]-cyclotriphosphazene (HGPCP) was designed and synthesized from commercial available hexachlorocyclotriphosphazene (HCCP). The chemical structure of HGPCP was characterized by fourier transform infrared (FTIR) spectroscopy, 1H, 13C and 31P NMR spectroscopy. Curing reaction of HGPCP with diamino diphenyl methane (DDM), diamino diphenyl sulfone (DDS) was investigated by non-isothermal differential scanning calorimetry (DSC), two-parameter autocatalytic equations of Sestak-Berggren were constructed to described the curing reaction rate quantitatively. Glass transition temperatures (Tg) of HGPCP/DDM and HGPCP/DDS were 191 °C and 196 °C, respectively, which were higher than that of DGEBA/DDM (156 °C), and the cured HGPCP systems had better thermal stability than DGEBA thermoset. The flame retardant properties of HGPCP/DDM and HGPCP/DDS were investigated by limiting oxygen index (LOI), vertical burning test (UL-94), the results revealed that cured HGPCP thermoset successfully passed UL-94 V-0 flammability rating with LOI values above 30%, indicating that HGPCP possessed excellent flame retardancy. Furthermore, HGPCP/DDM and HGPCP/DDS both have higher tensile strength than DGEBA/DDM, while the failure strains were lower than DGEBA/DDM which may due to the much higher cross-linking densities.