Combination Effect of Organically Modified Montmorillonite and Nano‐Silica on Reducing the Fire Hazards of Intumescent Flame‐Retarded Epoxy Resins. Issue 4 (12th March 2020)

• Record Type: Journal Article
• Authors: Yan, Long; Xu, Zhisheng; Jia, Hongyu; Chu, Zhiyong
• Is Part Of: Journal of vinyl & additive technology. Volume 26:Issue 4(2020)
• Page Start: 490
• Page End: 501
• Publication Date: 2020-03-12
• Subjects: epoxy resin -- fire hazard -- intumescent flame retardant -- nano‐silica -- OMMT; Vinyl polymers -- Periodicals; Plastics -- Additives -- Periodicals; 668.4236
• DOI: 10.1002/vnl.21764
• Languages: English
• ISSNs: 1083-5601

Abstract

Abstract: The combination effect of organically modified montmorillonite (OMMT) and nano‐SiO2 on the fire behavior of intumescent flame‐retarded epoxy resins (EPs) was evaluated. The results from fire tests show that the combination of intumescent flame retardant (IFR), OMMT, and nano‐SiO2 exerts an outstanding synergistic effect on improving the flame retardancy and smoke suppression properties of EPs. For example, the IFR‐3 sample, filled with 27 wt% IFR, 1.5 wt% OMMT, and 1.5 wt% nano‐SiO2, achieves the limiting oxygen index value of 28.2% and passes the UL 94 V‐0 rating, and exhibits a 33.2% reduction in total heat release and 49.3% reduction in total smoke release compared to those of IFR‐0 filled with 30 wt% IFR. Thermo‐gravimetric analysis shows that the combination of IFR, OMMT, and nano‐SiO2 shows a notable improvement in the char‐forming ability of EPs. More importantly, the combination of OMMT and nano‐SiO2 exerts a better synergistic effect on the char‐forming and fire safety of the intumescent flame‐retarded EPs compared to the case of OMMT or nano‐SiO2 alone. This phenomenon is ascribed to the fact that the uniform dispersions of OMMT and nano‐SiO2 particles can facilitate the formation of a more compact and continuous intumescent char against the transmission of heat and combustible gases, thus effectively reducing the fire hazards of the EP composites. Research Highlights: Organically modified montmorillonite (OMMT)/nano‐SiO2 were well dispersed in EP matrix according to X‐ray diffraction and scanning electron microscopy analyses. OMMT/nano‐SiO2 shows a well synergism in reducing the fire hazards of the epoxy resin (EP) composites. Obvious improvement in char‐forming ability is achieved by addition of OMMT/nano‐SiO2 . The synergistic mechanism of OMMT/nano‐SiO2 in the EP composites was well proposed.