%0 Journal Article
%T Two high
%A Peilong Wang
%A Xianling Fu
%A Xin Wang
%A Yongchun Kan
%A Yuan Hu
%J High Performance Polymers
%@ 1361-6412
%D 2019
%R 10.1177/0954008318762037
%X In this work, two kinds of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO)-based phosphonamidate flame retardants named 4,4¡ä-diamino-diphenyl methane (DDM)-DOPO and morpholine (MPL)-DOPO are successfully synthesized by the classic Atherton¨CTodd reaction, and their chemical structures are characterized by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). Epoxy composites containing DDM-DOPO or MPL-DOPO are prepared, which still retain relatively high transparency compared with pure epoxy resin (EP). Its fire behavior is studied in terms of vertical burning test (UL-94), limiting oxygen index (LOI), and cone calorimeter tests. The LOI values can achieve 30% and UL-94 test past V-0 rating for DDM-DOPO-modified epoxy composites with 0.25 wt% phosphorus content. The cone calorimeter results indicate that the modified epoxy composites can release less heat and smoke compared with pure EP. Also, thermal degradation behavior and flame-retardant mechanism of epoxy composites are investigated by thermogravimetric analysis and thermogravimetric analysis/infrared spectrometry. The results indicate that two DOPO-based phosphonamidates show a significant gaseous-phase effect on reducing the release of combustible volatiles
%K Epoxy resin
%K thermal degradation
%K flame retardancy
%K high efficiency
%K high transparency
%U https://journals.sagepub.com/doi/full/10.1177/0954008318762037