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

Abstract

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. © 2018 Society of Plastics Engineers

Castor‐oil derived nonhalogenated reactive flame‐retardant‐based polyurethane foams with significant reduced heat release rate

“…This could be due to the low thermal stability of P‐O‐C and P‐C bonds within the FR polyol . In principle, phosphorus compound contributes to flame retardancy in two distinct ways, namely, condensed phase and gas phase . At higher temperature, thermal decomposition of P‐O‐C and P‐C bonds result in phosphinic acid within the condensed phase of the foams, causing transesterification reaction accelerating dehydration of the foams and forming intumescent barrier char structure .…”

“…14,16,31 In principle, phosphorus compound contributes to flame retardancy in two distinct ways, namely, condensed phase and gas phase. 32 At higher temperature, thermal decomposition of P-O-C and P-C bonds result in phosphinic acid within the condensed phase of the foams, causing transesterification reaction accelerating dehydration of the foams and forming intumescent barrier char structure. 14,31,32 Barrier char layered over the surface of the foams, prevents the direct contact of the oxygen, thermal energy and combustible media providing flame retardancy.…”

Recent Advancement in Plant Oil Derived Polyol‐Based Polyurethane Foam for Future Perspective: A Review

“…Zhang et al . Synthesized flame‐retardant CO‐based PUF by incorporation of soy protein isolates (SPI) into polyol.…”

“…Liquefaction process was applied at different temperatures and the effect of all external parameter investigated, the mechanical response and thermal stability of prepared foam were improved. Recently, Zhang et al . synthesized highly flame‐retardant PUF using orange peel oil using one‐step photochemical thiolene reaction.…”

“…PUs are widely used in the synthesis of foams, coatings, adhesives, films, and elastomers, and among them, PUF has the largest market share—quantitatively more than 50%, currently. PUFs are used in various applications including thermal insulation in automotive, construction, footwear, acoustic, furniture, and packaging for the transportation of goods, and building insulation to reduce noise pollution . Currently, 95% of PUF industries are using the petroleum‐based polyols (polypropylene glycol and polyethylene glycol [PEG]) and isocyanates (diphenylmethane diisocyanate [MDI], toluene diisocyanate) for synthesizing PU .…”