rigid polyurethane foam with phosphorus–nitrogen intumescent flame retardant.pdf

Original Article High Performance Polymers 25(7) 868–875 Preparation and properties of flame ª The Author(s) 2013 Reprints and permission: retardant rigid polyurethane foam with sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/0954008313489997 phosphorus–nitrogen intumescent flame retardant 1,2 1,2 1,2 Denghui Wu , Peihua Zhao , Mei Zhang and Yaqing Liu 1,2 Abstract Ethanolamine spirocyclic pentaerythritol bisphosphonate (EMSPB), a novel intumescent flame retardant, was synthesized and used to improve the flame retardancy of rigid polyurethane foam (RPUF). The effects of EMSPB on the flammability, thermal stability, and mechanical properties of RPUF were discussed, respectively. Scanning electron microscopy (SEM) and compression strength tests showed that the EMSPB had favorable compatibility with the RPUF matrix and did not deteriorate the mechanical properties of the RPUF. Flammability of RPUF systems containing various contents of EMSPB was investigated by vertical burning test (UL-94) and limiting oxygen index (LOI) test. Results indicated that when the content of EMSPB was 25 wt%, the LOI of flame retardant RPUF could reach 27.5%, and a UL-94 V-0 rating was achieved. Thermogravimetric analys