Flame retardance of a bio-based furan resin: Effects of added flame retardants

Abstract

A study of the flammability of a biobased furan resin via limiting oxygen index and UL-94 has shown its inherent flame retardant properties. In a cone calorimetric test at 50 kW/m2 external irradiance, however, it ignited within 50 s and burnt, producing 489 kW/m2 peak heat release and 24 MJ/m2 total heat release but minimal smoke production. The flame retardance of the furan resin was further improved by the addition of the phosphorus-containing inorganic flame retardants, ammonium polyphosphate (APP) and melamine polyphosphate (MPP), and their well known condensed phase activity was further supported by thermogravimetric analysis (TGA). The organic flame retardants, resorcinol bis(diphenyl phosphate) (RDP) and bisphenol-A bis(diphenyl phosphate) (BAPP) had no effect on flame retardance, and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) had only minimal effects in LOI and cone calorimetric tests, which was at variance to the results of TGA tests. This disconnect between the tests involving flaming combustion (LOI and cone calorimetry) and slow controlled heating (TGA) was attributed to the low flash points and high boiling points of the organic flame retardants, respectively.