Highly flame retardant and bio-based rigid polyurethane foams derived from orange peel oil

Limonene dimercaptan (LDM), an orange peel oil-based derivative, and glycerol-1-allyl ether (GAE) were used to synthesize bio-based polyol (LDM-GAE) using one step photochemical thiol-ene reaction. The synthesized polyol was used to prepare flame retardant polyurethane foams using dimethyl methyl phosphonate (DMMP) as an additive flame retardant (AFR) and a new bromine containing reactive flame retardant (RFR) derived from 2,4,6-tribromophenol. Both flame retardants lead to rigid polyurethane foams with excellent physical-mechanical properties with a short self-extinguishing time (7.5 and 12.8 sec for DMMP and bromine-based foams, respectively) and with low weight loss after burning. The reactive bromine polyol lead to rigid polyurethanes with better physical-mechanical properties than those of foams based on AFR with phosphorous, but the flame retardant properties of foams prepared using AFR are superior to the foams prepared using bromine polyol (RFR). Low addition of DMMP is sufficient to reduce the flammability of polyurethane foam without compromising its physical-mechanical properties. These flame retardant rigid polyurethane foams based on limonene dimercaptan can be used in all applications of rigid polyurethane foams especially where flammability is an issue such as for insulation of buildings. POLYM. ENG. SCI., 58:2078-2087, 2018. (c) 2018 Society of Plastics Engineers