Comparative Analysis of Flame Characteristics of Castor Oil and Some Other Inorganic Flame Retardants Used in Polyurethane Foam Systems

Abstract

The flame characteristics of castor oil based foam and that of polyether foam impregnated with inorganic flame retardants (FR) were investigated. The polyether foams were impregnated with measured concentration of Antimony trioxide and Sodium bromide, Ammonium dihydrogen orthophosphate, Diammonium hydrogen orthophosphate, and Castor oil containing zero flame retardant. Incorporating these flame retardants into polyurethane formulations gave variable flame characteristics such as ignition time, flame propagation rate, after glow, char rate, add-on and glow time. These properties were measured as a function of concentration and type of flame retardant incorporated into the formulation. Result showed that ignition time and Add-On showed significant increase in this sequence-Castor oil>Ammonium dihydrogen orthophosphate> Diammonium hydrogen orthophosphate>Antimony trioxide/Sodium bromide, at all the different concentrations, while flame-propagation rate and After-glow decreased in the same sequence for all the FR used at different concentrations. However the %Char increased in a reverse order Diammonium hydrogen orthophosphate>Ammonium dihydrogen orthophosphate>Antimony trioxide/Sodium bromide>Castor oil. These results show that castor oil is an effective flame retardant compared to the inorganic flame-retardants.