Nano-synergies in conventional flame retardants

Abstract: In this master thesis the effects of adding nanoparticles to conventional flame retardants has been examined. The main part of the work has been carried out at Saab Barracuda AB (Barracuda) in Gamleby, and part of the work has been carried out at the Swedish Defense Research Agency (FOI) and Exova, both in Linköping, as well as The Faculty of Engineering in Lund. The work focuses on whether the addition of certain nanoparticles, carbon-nanotubes or nanoclay, can improve the flame retardancy of the already existing conventional flame retardants used by Barracuda. From the results, different conclusions are put forth regarding how the correlation between the addition of nanoparticles and the flammability characteristics could look like. A large number of samples \newline (~400) have been fabricated and subjected to tests such as the ISO 6941 standard, scanning electron microscopy, cone calorimetry and light microscopy in order to evaluate the fire retardancy and the possible explanations for the aforementioned. The main part of the samples were fabricated by coating a textile fabric with a mixture of either solely the flame retardant or a mixture by the flame retardant and nanoparticles. It is clear that adding carbon-nanotubes to the conventional flame retardants strongly improves variables such as burn time, and heat release rate. The addition of nanoclay can both improve as well as deteriorate the flame retardancy. The dispersion method for the nanoclay seems to play a vital role on the end result, and further tests are needed in order to make a comprehensive conclusion. The methodology from the thesis shows an easy, effective and commercially viable method for evaluating potential effects that the addition of nanoparticles have on conventional flame retardants. The results can be used by either Barracuda or by the flame retardant manufacturers to develop a more effective flame retardant. This thesis only examines two, out of many possible, nanoparticles, and the effects they have on two conventional flame retardants.