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

Abstract

National Fire Protection Association encounters one structural fire every 66 s. Rigid polyurethane foam is one of the principal components used in constructional and household applications. In this work, a reactive flame retardant (FR) was synthesized using a facile one‐step thiol–ene reaction by reacting mercaptenized castor oil (MCO) and diethyl allyl phosphonate (DEAP). The obtained MCO–DEAP polyol was used for the preparation of polyurethanes having different weight percentages of phosphorus (P). Addition of FR polyol showed no adverse effect on the cellular structure of the foams and maintained the compressive strength. All the foams showed closed cell content greater than 95%. Horizontal burning test (HBT) was performed before and after the migration test to understand the stability of the FR within the foams. Foams showed no relative weight loss before and after the migration test and maintained equivalent results for HBT. For 1.5 wt % P foams, low extinguishing time of 3 s and weight loss of 4% was observed. The cone calorimeter test showed a reduction in the peak heat release rate from 313 to 158 kW m−3, the total heat release from 18 to 8 MJ m−2, and O2 consumption from 12 to 6 g. Our results suggest that MCO–DEAP polyol could act as an essential FR for rigid PU foam ensuring fire safety. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47276.

Novel Biobased Polyol Using Corn Oil for Highly Flame-Retardant Polyurethane Foams

“…In order to counter this issue, compounds such as additive and reactive flame retardants consisting of halogenated and non-halogenated compounds or, inorganic metal oxides, and hydroxides are added within the foam matrix during the synthesis [8,19,20]. Reactive flame retardants consist of compounds with functional groups that can readily get bonded within the foam matrix [6,8,9,21]. In practice, separate synthesis for such flame retardants could add to the cost of the final foams, while additive flame retardants consist of simple compounds and require very little concentrations to impart flame retardancy [7].…”

The Prospering of Macromolecular Materials Based on Plant Oils within the Blooming Field of Polymers from Renewable Resources

“…A castor oil-based mercaptan, 1,3,5-triethylene-1,3,5-trimethylcyclotriazane (TCC), and a phosphorus-containing flame-retardant molecule (AD) were compounded via photo-initiated thiol-ene click reaction (DMPA photoinitiator under 365 nm light) to create a flame-retardant coating on wood surfaces [ 56 , 57 ] ( Figure 8 ). In a similar way, diethyl allyl phosphonate A was inserted via thiol-ene reaction into a commercial mercaptanized castor oil, and the ensuing polyol was used for the preparation of rigid polyurethanes with different weight percentages of phosphorus and with promising flame retardancy properties, ensuring fire safety for construction and household applications [ 58 ].…”

Flame Retardancy of Bio-Based Polyurethanes: Opportunities and Challenges

“…The authors explained this improvement by formation of phosphinic acid during the combustion and formation of a protective char layer on the surface of the foam. Bhoyate et al [93] also examined the effect of a bio-based mercaptenized castor oil polyol, modified with DEAP in the PU. Surprisingly, similar results have been obtained in cone calorimetry tests.…”