1Departamento de Engenharia Quimica e Engenharia de Alimentos, Universidade Federal de Santa Catarina 2Lehrstuhl Keramische Werkstoffe, University of Bayreuth
The latest technologies require materials with properties not found in conventional ones, such as thermal stability or resistance to light and heat. To overcome these limitations, hybrid polymers can be prepared by combination of different organic and inorganic materials to achieve optimized properties. Recently, silicon-containing compounds, including silicon carbonitride, are being studied in the preparation of hybrid polymers. These materials could act as flame retardants in condensed phase, creating a protective ceramic layer that hinders the flame spread. To make this new material useful in the industrial scale, melt processing technique is the most attractive preparation method, due to low costs and high productivity. In this work the hybrid blends processed containing inorganic polyssilazanes and organophosphorus flame retardants added as fillers in the polystyrene matrix was evaluated, to study the synergism between the compounds on the hybrid material thermal behavior. The effect of the fillers inclusion at the flame propagation retardancy and non-dripping effect was analyzed by UL94 vertical Burning, ASTM D-365 horizontal bunring and thermogravimetric analysis. The samples where prepared in a single screw extruder, with the zone temperatures and screw speed parameters previously studied, and the application of the retardancy tests followed the flammability tests criterias. The results revealed that the addition of ceramic precursor and organophosphorus compounds enhanced the thermal stability and flame retardancy of PS significantly. The synergistic effect of the fillers and the formation of a ceramic protective layer caused by the addition of precursor was observed in the final product.
