Phosphoramidate-Containing Flame-Retardant Flexible Polyurethane Foams

Abstract

In this study, we have investigated the structure–flame-retardant (FR) efficacy relationships of phosphoramidates (PRs) on flexible polyurethane foam (FPUF). FPUFs that contain model monosubstituted secondary PRs, monosubstituted tertiary PRs, and trisubstituted secondary PRs were prepared and evaluated for FR efficacy and thermal decomposition characteristics. The fire test results indicate that methyl ester PRs exhibit better FR behavior, compared to analogous phenyl ester derivatives at equal weight percentage in polyurethane (PU) foams. Within the same class of PRs, the monoallyl derivatives exhibited the highest level of flame retardancy. The multiallyl PR derivatives did not offer any advantage, in terms of improved flame retardancy. Evolved gas analysis from the thermal degradation of PU foams indicates that the PRs are volatilized in the first stage of thermal decomposition and are primarily active in the gas phase with the exception of the triallyl-PR derivative, which is primarily active in the condensed phase.

Effect of Meltable Triazine-DOPO Additive on Rheological, Mechanical, and Flammability Properties of PA6

“…Thus, the value of T 5 was of about 386˝C, the decomposition process registered a single stage with a reduction of 20˝C in the value of T max (430˝C), while the char yield had a value of 0.9 wt %. Similar data, regarding the influence of the additive on thermal stability, were obtained for different polymers and FR based on DOPO derivatives [26][27][28]. The incorporation of various DOPO-based FR additives led to a decrease in thermal stability of the corresponding polymers.…”

“…Melamine also destabilizes PA6 and increases the dripping behavior of the polymer; therefore, the fuel source is removed from the combustion zone [22]. Concerning the phosphorous-containing flame retardants, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and its derivatives could be an attractive FR solution for PA6 due to their relatively higher thermal stability [25][26][27][28]. DOPO and its derivatives are known to predominantly act by a gas-phase mechanism, through the formation of PO¨radicals, which might also be assisted by a condensed-phase activity via the incorporation of specific functionalities at the DOPO moiety [25,29].…”

Recent developments in P(O/S)–N containing flame retardants

“…29,30 More recently, one pot two-step approach has been employed to convert P─H bonds to P(O)-N bonds. 23,36,[38][39][40] and P(O)─Br via N-bromosuccinimide. 23,36,[38][39][40] and P(O)─Br via N-bromosuccinimide.…”

“…12 Such interactions lead to the reduction of the load of FRs in the material and improved FR efficacy. 22,23 Recently, gas phase species such as phosphorus nitride (PN) and other PN species have been detected during the thermal decomposition of dimethyl phosphoramidate. 19,20 The use of phosphorus-nitrogen (P-N) compounds as FRs are extensively studied, and their FR effect in many cases is attributed to P-N synergism.…”

Recent advances in “living”/controlled radical polymerization of phosphorus-containing monomers and their potential applications

“…Conventional radical (co)-polymerization can be suitable for most kinds of monomers and has low operational cost, which are desirable for industrialized production [18]. Quittmann et al [19] introduced the synthesis of a novel phosphonated dimethacrylate 1 (Scheme 1) and studied its homo photocuring kinetics.…”