Influence of Different Flame Retardants on Fire Behaviour of Rigid Polyurethane Foams Blown with n-Pentane

One of the most currently used blowing agents for rigid Polyurethane foam is n-pentane because, unlike CFC-11, it has 0 ODP (Ozone Depletion Potential) and low GWP (Global Warming Potential), but unfortunately it is flammable. The assessment of the influence of different flame retardants (FR) to improve flame retardancy behaviour of polyurethane (PUR) and polyisocyanurate (PIR) foams is therefore very important, as these materials are often used in application fields which require a certain level of flame retardancy. In particular, our investigations focused on the use of both additive and reactive type phospho-halogenated products and phosphorus based halogen-free compounds, keeping in mind that the FRs must accompany the future trends, meeting all the new environmental requirements. The results obtained using small-scale tests show that good results in terms of burning behaviour can be achieved by using FR compounds with high phosphorus content both in PUR and PIR-PUR systems. Physico-mechanical properties of the foams were only slightly influenced by the addition of these FR compounds.