An Investigation on Fire and Flexural Mechanical Behaviors of Nano and Micro Polyester Composites Filled with SiO 2 and Al 2 O 3 Particles

This study is aimed at developing a new type of unsaturated polyester based composite material with enhanced fire retardancy through polymer matrix modification with nano/micro oxide particles, such as silicon dioxide, carbon-coated silicon dioxide and aluminium oxide, in combination with common flame retardants systems. For this purpose, the design of experiments based on Taguchi methodology and analyses of variance were applied. Samples with different material and processing parameters resultant from L9 Taguchi orthogonal array were produced, and their fire and mechanical properties were assessed and quantified by vertical flammability tests (UL-94), flexural and Charpy impact tests. The effect of the sonication time of mixtures on final properties was also assessed. It was found that both material and processing parameters have different effects on the various analysed properties. The results revealed that addition of hybrid flame retardant systems introduced reasonable improvements in at least one fire reaction property; however, filler addition also led to decreases in some mechanical properties, most likely due to poor matrix-filler adhesion. Future studies are anticipated in order to improve mix design formulations towards further fire retardancy enhancement without significantly compromising mechanical properties.