Synergistic effects of zinc borate and aluminium trihydroxide on flammability behaviour of aerospace epoxy system

Abstract

Abstract. The flame retardancy of mono-component epoxy resin (RTM6), widely used for aerospace composites, treated with zinc borate (ZB), aluminium trihydroxide (ATH) and their mixtures at different concentrations have been investigated by morphological and thermal characterization. Cone calorimeter data reveal that combustion behaviour, heat release rate peak (PHRR) and heat release rate average (HRR Average) of RTM6 resin decrease substantially when synergistic effects of zinc borate and aluminium trihydroxide intervene. Thermogravimetric (TGA) results and analysis of the residue show that addition higher than 20% w/w of ZB, ATH, and their mixture greatly promotes RTM6 char formation acting as a barrier layer for the fire development. Depending upon the different used flame additives, SEM micrographs indicate that the morphology of residual char could vary from a compact amalgam-like structure, for the RTM6+ZB system, to a granular structure, characterized by very small particles of degraded resin and additive for the ATH.

Comparative study of boron compounds and aluminum trihydroxide as flame retardant additives in epoxy resin

“…Boron compounds considered as environmentally friendly are also used as a flame retardant agent either solely or with commercial flame retardants for their synergistic effect in epoxy resins . Formicola et al .…”

“…studied the synergistic interaction between ATH and ZnB in epoxy resin. It was concluded that the combination of two fillers at a lower specific content showed synergistic interaction . Jimenez et al .…”

Boron‐Based Flame Retardants in Non‐Halogen‐Based Polymers

“…Formicola et al reported the use of a combination of ATH and zinc borate in epoxy for aerospace application. Th eir Cone Calorimeter results demonstrated that zinc borate promotes the formation of a strong char via sintering with alumina and results in substantial decrease of pHRR, aveHRR of epoxy resin [68]. Synergy was observed when the total loading reaches 20% or higher at 1:1 ratio of zinc borate:ATH.…”

Alüminyum Eloksal Atıklarının Yangın Geciktirici Olarak Değerlendirilmesi

“…Organik bileşiklerin aksine, inorganik alev geciktiriciler ısı etkisiyle buharlaşmaz; bunun yerine H2O gibi zararsız, CO2 gibi daha az zararlı gazlar açığa çıkararak bozunurlar. En çok kullanılan inorganik alev geciktiriciler magnezyum hidroksit, aluminyum trihidrat ve çinkoborattır [7][8][9][10]. Ayrıca alev geciktirici maddelerin malzemeye katılması malzemenin fiziksel ve kimyasal özelliklerine etki edeceğinden katılma oranları önemlidir, belirlenmesi gerekir [11].…”