Physical Recovery and Flame Retardant Research in Rigid Polyurethane Foam of Phenolic Foam
【Abstract】 Using waste phenolic foam powder particles as carbon source and ammonium polyphosphate( APP) as acid and gas source to form a new chemical expansion flame retardant composite system,which was added into the premix of rigid polyurethane foam,a new foam material with high flame retardancy was prepared by way of foaming process. In order to illustrate the effects, parts of the waste phenolic foam powders were carbonized at high temperatures. The effect of content of flame retardant particles on compressive strength,modulus of compressibility,oxygen index,thermal conductivity and burning surface appearance were studied. The results showed that the functional groups on the surface of PF particles participated in the polyurethane foaming reaction,thus improving the binding force of the particles’ interface and the compressive strength of the foam. After PF particles composite with APP were added into the polyurethane foaming system, the formed intumescent char layer through burning played a good flame retardant effect and the oxygen index of the foam was significantly increased.