Synthesis of a phosphorus‐ and nitrogen‐containing flame retardant and evaluation of its application in waterborne polyurethane

In this study, flame-retardant polyamide 6 (PA6) fibers incorporated with hexaphenoxycyclotriphosphazene (HPCP) were prepared by melt spinning. The effects of HPCP on the mechanical, thermal, and flame-retardant property of PA6 fibers were investigated. The results indicated that PA6 fibers containing less than 15 wt % of HPCP possessed acceptable spinnability. HPCP resulted in a slight decrease in tensile strength and tensile modulus, however, an enhancement of the flexibility. Thermal decomposition temperature of PA6 fibers reduced about 22 C but the residue at 800 C increased. At the loading of 10 wt %, PA6 fibers reached a limiting oxygen index value of 28.6% and had no smoldering time in the vertical oriented burning. Residue analysis by Fourier-transform infrared and scanning electron microscope revealed that a condensed phase mechanism was involved in the decomposition of PA6/HPCP system. Pyrolysis-gas chromatography-mass spectrometry results demonstrated that HPCP not affected the composition of the pyrolysis gases, but mainly intensified the effusion of nonflammable gases, which is positive to flame retardancy. Therefore, the PA6/HPCP composite fibers would get access to satisfactory applications as flame-retardant materials.

Section: Resultsmentioning

confidence: 98%

Experimental investigation of mechanical, thermal, and flame‐retardant property of polyamide 6/phenoxyphosphazene fibers

Zhao

et al. 2019

“…72 In the gas phase, the material produces water (H 2 O) and carbon dioxide (CO 2 ) along with PO * species and suppress the production of flammable gasses such as ether and benzene. 75 A novel P-N containing FR, octahydro-2,7-di(N,N-dimethylamino)-1,6,3,8,2,7-dioxadiazadiphosphecine (21) as shown in figure 7 was synthesized in three steps. Due to this two-phase mechanism, EG/DEPA system exhibits excellent flame retardancy in RPUF.…”

Section: Polyurethanesmentioning

confidence: 99%

“…Further, phosphoric acid condenses into polyphosphoric acid to enable char formation via the carbonization process. 75 A novel P-N containing FR, octahydro-2,7-di(N,N-dimethylamino)-1,6,3,8,2,7-dioxadiazadiphosphecine (21) as shown in figure 7 was synthesized in three steps. In the first step, phosphorus oxychloride (POCl 3 ) reacts with dimethylamine hydrochloride in dichloromethane solution in the presence trimethylamine base.…”

Section: Polyurethanesmentioning

confidence: 99%

“…116 In many cases, it is claimed that P(O)-N compounds offer synergism and improved flame retardancy of cellulose. [116][117][118] A series of alkyl ester phosphoramidates derivative (69)(70)(71)(72)(73)(74)(75) as shown in figure 20 were synthesized and incorporated in cellulose fibers obtained from a different source (peat and cotton fibers).…”

Section: Cellulose Fibersmentioning

confidence: 99%

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

Nazir

Gaan

2019

Synthesis of organophosphorus compounds containing nitrogen as heteroatom and its application as a flame retardant (FR) have attracted much attention in the academic and industrial communities over the past decade. Such compounds are relatively easy to synthesize and offer advantages such as high thermal stability, which is useful for high temperature processing, improved char stability, density, and yield during the thermal decomposition of polymer, and release phosphorus species active in the flame inhibition process. Though a variety of phosphorus-nitrogen (P-N) compounds can be found in the literature, this review mostly summarizes the recent (since 2013) development in phosphorus (O)-nitrogen containing flame retardants which have been published in peer-reviewed journals. General strategies of synthesizing P(O)-N compounds as FRs from various phosphorus-based starting materials are highlighted in this review. Some of the most common classes of researched P(O)-N containing compounds as FRs include the phosphinamides, phosphonamides, phosphoramides, phosphoramidates, phosphorodiamidates, phosphonamidates and their thio counterparts which are usually obtained via a one-or two-step synthetic strategy. Incorporation of these compounds as FRs in various polymer systems such as polyurethane, epoxy resins, polyamides, cellulose, polylactide, poly(butylene terephthalate), polycarbonates, and acrylonitrile-butadiene-styrene are discussed in detail in this review. Special emphasis on the various fire and thermal performances of the new materials are also summarized. The mechanical performance of new materials and the influence of these additives on polymer processing are also briefly discussed.

“…Considering that APP has been well proved to be the most suitable acid and gas source up to now, many investigations have been done on the char‐forming agent by researchers, and they found that the introduction of some certain functional groups might achieve excellent char‐forming ability and then promote to develop the novel high‐efficient IFR . For instance, pentaerythritol octahydrogen tetraphosphate (PEPA) has proved to be an effective char‐forming functional group . Wang et al .…”

Section: Introductionmentioning

confidence: 99%

Synthesis of a novel char‐forming agent (PEIC): Improvement in flame retardancy, thermal stability, and smoke suppression for intumescent flame‐retardant polypropylene composites

Xiang

Yang

Hua

et al. 2019

A novel char-forming agent named PEIC was designed and synthesized combining pentaerythritol octahydrogen tetraphosphate (PEPA) and tris(2-hydroxyethyl) isocyanurate. PEIC was combined with the silica-gel-microencapsulated ammonium polyphosphate (OS-MCAPP), preparing intumescent flame-retardant polypropylene (PP) composites. The results of the limiting oxygen index (LOI) show that the composite containing 30 wt % IFR with OS-MCAPP:PEIC = 2:1 presents the optimal LOI of 32.7%. Meanwhile, the cone calorimeter tests show that its peak heat release rate is 432 kW m −2 , which decreases by 62.1% compared with that of pure PP, showing a high-efficient flame retardancy. The exhibited UL-94 V-0 rating for all the composites indicates that the IFR composed of PEIC and OS-MCAPP has high-efficient flame retardancy in PP. The analysis of residue char reveals that PEIC could improve the quality of char in compactness, intumescentia, and the degree of graphitization. Further, the effect of IFR on the mechanical properties of PP composites was also evaluated and discussed.