Halogen Free Flame Retardant Based on Organophosphorus Compounds for Expandable Polystyrene Produced by Supension Polymerization

摘要

Expandable polystyrene (EPS) has been widely used in many fields of engineering butrnpresent some inconveniences at higher temperatures. When exposed to a heat sourcernthe polymeric material decomposes forming volatile combustible products turningrnEPS an easily flammable material. During a long time, the halogen-based compoundsrnhave been incorporated as an additive flame retardant (FR) for different class ofrnpolymeric materials with a good efficiency. Nowadays, plastic industry is sufferingrnhard pressures from health organizations once combustion of halogen-basedrncompounds generates the formation of smoke with a number of negativerncharacteristics. Searching for an environmental safety FR option it was studied tworndifferent FR compounds, one of them based on organophosphorus compounds, whosernworks together to provide efficiency as good as the efficiency provided by halogenbasedrncompounds, like hexabromocyclododecane. Fire retardant effectiveness isrnobtained through the compounds synergies were each FR has to act in differentrnmechanism complementary. Both FRs are added in situ, during the polymerizationrnreaction. Good flame retardancy was obtained with the FR tested. Results demonstraterna reduction of more than 50% in the burning rate of EPS.