FLAME-RETARDANT RIGID PU FOAM WITH A NOVEL REACTIVE PHOSPHORAMIDATE AND EXPANDABLE GRAPHITE

摘要

A novel reactive phosphoramide named diethyl-N,N-bis(2-hydroxyethyl) phosphoramide (DEPA) and expandable graphite (EG) were combined together to flame retard rigid PU foam (RPUF) via free box-foaming.DEPA could be introduced to PU molecular chain with chain extension reaction of double hydroxyl.The LOI value of RPUF achieved 30.4％ when 8 wt％ EG and 16 wt％ DEPA were incorporated.Meanwhile, this flame retardant system obtained the lowest peak heat release rate (pHRR, 139.9 kW/m2) in the samples studied.Thermogravimetric analysis (TGA) results show that EG/DEPA system enhanced the residue chars of RPUF.DEPA and EG showed obvious synergetic flame retardant in RPUF.