A brief review on fire retardants for polymeric foams

Wang, J. Q.; Chow, Wan Ki

doi:10.1002/app.21758

Cited by 100 publications

(87 citation statements)

References 18 publications

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“…It is thus thought that DMC and DMO are formed in related elementary reaction steps. Their respective yields will depend on the relative abundance of species I and II, which is determined by the competition between CO and CH 3 O À for a coordination site at the palladium centre in I. Further details of this methanol carbonylation process and factors that influence the rate and selectivity of these reactions will be subject of a separate publication.…”

Section: Discussionmentioning

confidence: 99%

“…Carbonylation reactions (7) are thought to proceed by displacement of the anionic CH 3 O À moiety by CO coordination and subsequent nucleophilic attack of methoxide on coordinated CO forming P 2 2 (II) which again gives P 2 Pd 0 upon reductive elimination of DMO. It is thus thought that DMC and DMO are formed in related elementary reaction steps.…”

Section: Discussionmentioning

confidence: 99%

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Carbonylation of Nitrobenzene in Methanol with Palladium Bidentate Phosphane Complexes: An Unexpectedly Complex Network of Catalytic Reactions, Centred around a Pd–imido Intermediate

Mooibroek

Schoon

Bouwman

et al. 2011

Chemistry A European J

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The reactivity of palladium complexes of bidentate diaryl phosphane ligands (P(2)) was studied in the reaction of nitrobenzene with CO in methanol. Careful analysis of the reaction mixtures revealed that, besides the frequently reported reduction products of nitrobenzene [methyl phenyl carbamate (MPC), N,N'-diphenylurea (DPU), aniline, azobenzene (Azo) and azoxybenzene (Azoxy)], large quantities of oxidation products of methanol were co-produced (dimethyl carbonate (DMC), dimethyl oxalate (DMO), methyl formate (MF), H(2)O, and CO). From these observations, it is concluded that several catalytic processes operate simultaneously, and are coupled via common catalytic intermediates. Starting from a P(2)Pd(0) compound formed in situ, oxidation to a palladium imido compound P(2)Pd(II)=NPh, can be achieved by de-oxygenation of nitrobenzene 1) with two molecules of CO, 2) with two molecules of CO and the acidic protons of two methanol molecules, or 3) with all four hydrogen atoms of one methanol molecule. Reduction of P(2)Pd(II)=NPh to P(2)Pd(0) makes the overall process catalytic, while at the same time forming Azo(xy), MPC, DPU and aniline. It is proposed that the Pd-imido species is the central key intermediate that can link together all reduction products of nitrobenzene and all oxidation products of methanol in one unified mechanistic scheme. The relative occurrence of the various catalytic processes is shown to be dependent on the characteristics of the catalysts, as imposed by the ligand structure.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Carbonylation of Nitrobenzene in Methanol with Palladium Bidentate Phosphane Complexes: An Unexpectedly Complex Network of Catalytic Reactions, Centred around a Pd–imido Intermediate

Mooibroek

Schoon

Bouwman

et al. 2011

Chemistry A European J

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“…They form a carbonaceous foam residue on the surface that acts as a heat insulator and a physical barrier to the transport of oxygen and pyrolysis products. (2,(9)(10)(11) Expandable graphite (EG) is a partially oxidized, intercalated form of graphite. It contains intercalated guest species (e.g.…”

Section: Introductionmentioning

confidence: 99%

Cone calorimeter study of polyethylene flame retarded with expandable graphite and intumescent fire-retardant additives

Kruger

Focke

Mhike

et al. 2014

Journal of Fire Sciences

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Polyethylene was flame retarded with an intumescent flame retardant at 27 wt.% and expandable graphite at 10 wt.% either on its own or in combination with 10 wt.% or 20 wt.% of the intumescent. Two grades of each flame retardant type were used. They differed primarily with respect to the onset temperature for exfoliation (commercially sourced expandable graphite types) or decomposition (intumescents). The latter were the highdecomposition-onset-temperature intumescent 3,5-diaminobenzoic acid phosphate and the commercially available low-decomposition-onset-temperature ethylenediamine phosphate. The fire performance of pressed sheets with a nominal thickness of 3.2 mm was tested in a cone calorimeter at a radiant flux of 35 kW m 2 . The best char yields were obtained with compositions containing 3,5-diaminobenzoic acid phosphate. Despite this, the best fire overall performance was realized using ethylenediamine phosphate, together with the lowexfoliation-onset-temperature expandable graphite. Formulations based on this intumescent compound ignited later, reached the peak heat release rate earlier, and also burned longer irrespective of the expandable graphite grade used. This can be attributed to the formation, at the burning surface, of a more cohesive char with better thermal and mass transfer barrier properties. This explains why compositions based on ethylenediamine phosphate as intumescent outperformed those containing 3,5-diaminobenzoic acid phosphate in terms of the peak heat release rate and other important fire indices.

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“…Melamine is successfully used in flexible PU foams and other polymers as a halogen-free flame retardant (FR) [1][2][3]. The melamine itself, upon combusting of a polymer, acts only as a blowing agent, which dilutes flammable volatile products, released upon the decomposition of a polymer at high temperature [4].…”

Section: Introductionmentioning

confidence: 99%

Effect of melamine phosphate on the thermal stability and flammability of bio-based polyurethanes

Yakushin

Sevastyanova

Vilsone

et al. 2016

IOP Conf. Ser.: Mater. Sci. Eng.

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Abstract. The effect of melamine phosphate (MP) on the thermal stability of bio-based polyurethane and the flammability parameters of wood samples with polyurethane coatings was studied. Thermogravimetric analysis and cone calorimeter test at a heat flux of 35 kW/m 2 were used for this purpose. The main characteristics of the thermal stability and flammability of the coating with addition of MP were compared with the characteristics of analogous coatings with addition of ammonium polyphosphate (APP), as well as APP in combination with melamine. It was found that the use of MP as an intumescent additive allows a considerable decrease of most of the flammability parameters of the polyurethane based on tall oil fatty acids, like APP. To reach the maximum effect, it is enough to load in the polyurethane 20% of MP. In contrast to APP, MP reduces also the smoke release of the samples. Using MP in combination with APP at definite weight ratios, it is possible to essentially reduce the flammability parameters of polyurethane coatings, such as PHRR, THR and MARHE.

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A brief review on fire retardants for polymeric foams

Cited by 100 publications

References 18 publications

Carbonylation of Nitrobenzene in Methanol with Palladium Bidentate Phosphane Complexes: An Unexpectedly Complex Network of Catalytic Reactions, Centred around a Pd–imido Intermediate

Carbonylation of Nitrobenzene in Methanol with Palladium Bidentate Phosphane Complexes: An Unexpectedly Complex Network of Catalytic Reactions, Centred around a Pd–imido Intermediate

Cone calorimeter study of polyethylene flame retarded with expandable graphite and intumescent fire-retardant additives

Effect of melamine phosphate on the thermal stability and flammability of bio-based polyurethanes

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