Effects of silane-modified multiwalled carbon nanotubes and 9,10-dihydro-9-oxa-10 phosphaphenanthrene-10-oxide on the flame retardancy and mechanical properties of bismaleimide resin

In this article, the multiwalled carbon nanotubes modified by γ-aminopropyltriethoxysilane (MWCNT-APTES) and 9,10-dihydro-9-oxa-10 phosphaphenanthrene-10-oxide (DOPO) were added into the 4,4′-bismaleimidophenyl methane (BDM)/2,2′-diallyl bisphenol A (DBA) resins to prepare the flame retardant resins. Morphological observations reveal that the MWCNT-APTES is homogeneously dispersed in the matrix. The impact strength of the resin is improved by adding MWCNT-APTES. Meanwhile, BDM/DBA containing DOPO/MWCNT-APTES achieves vertical burning (UL-94) V-0 rating and a higher limiting oxygen index. Thermogravimetric analysis and scanning electron microscopy measurements have demonstrated that MWCNT-APTES resulted in the increase in char yield and the formation of the thermally stable carbonaceous char. The results of Raman show that the MWCNT-APTES can enhance the graphitization degree of the resin during combustion. All the investigations show that the combination of DOPO and MWCNT-APTES is an effective additive to develop high-performance resins with attractive flame retardance and mechanical properties.