Enhanced flame-retardancy and controlled physical properties of flexible polyurethane foams based on a shear-responsive internal network

Rao, Jingyi; Fernández‐Ronco, María P.; Vong, Michel; Gaan, Sabyasachi

doi:10.1039/c7ra07083g

Cited by 9 publications

(4 citation statements)

References 45 publications

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“…In the case when solid additives are used, they need to be dispersed well for uniform functional properties [21]. It has been demonstrated that a proper dispersion of additives in the polyol is necessary for long-term storage stability of bridged DOPO polyol dispersions [22]. Thus in an attempt to improve the flame retardancy of EDA-DOPO in formulations B, pre-dispersion of EDA-DOPO in polyol using a planetary ball mill was performed.…”

Section: Resultsmentioning

confidence: 99%

Some Key Factors Influencing the Flame Retardancy of EDA-DOPO Containing Flexible Polyurethane Foams

et al. 2018

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The role of various additives (emulsifier, anti-dripping agent) and formulation procedures (pre-dispersion of solid additives in polyol via milling) which influence the flame retardancy of 6,6′-[ethan-1,2-diylbis(azandiyl)]bis(6H-dibenzo[c,e][1,2]oxaphosphin-6-oxid) (EDA-DOPO) containing flexible polyurethane foams has been investigated in this work. For comparison, the flame retardancy of two additional structurally-analogous bridged 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO)-based compounds, i.e., ethanolamine-DOPO (ETA-DOPO) and ethylene glycol-DOPO (EG-DOPO) were also evaluated together with EDA-DOPO in flexible PU foams of various formulations. The flame retardancy of these three bridged-DOPO compounds depends on the type of PU formulation. For certain PU formulations containing EDA-DOPO, lower fire performance was observed. Addition of emulsifier and polytetrafluoroethylene (PTFE) to these PU formulations influenced positively the flame retardancy of EDA-DOPO/PU foams. In addition, dispersion of EDA-DOPO and PTFE via milling in polyol improved the flame retardancy of the PU foams. Mechanistic studies performed using a microscale combustion calorimeter (MCC) and its coupling to FTIR showed no difference in the combustion efficiency of the bridged-DOPO compounds in PU foams. From MCC experiments it can be concluded that these bridged-DOPO compounds and their decomposition products may work primarily in the gas phase as flame inhibitors. The physiochemical behavior of additives in PU formulation responsible for the improvement in the flame retardancy of PU foams was further investigated by studying the dripping behavior of the PU foams in the UL 94 HB test. A high-speed camera was used to study the dripping behavior in the UL 94 HB test and results indicate a considerable reduction of the total number of melt drips and flaming drips for the flame retardant formulations. This reduction in melt drips and flaming drips during the UL 94 HB tests help PU foams achieve higher fire classification.

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Section: Resultsmentioning

confidence: 99%

Some Key Factors Influencing the Flame Retardancy of EDA-DOPO Containing Flexible Polyurethane Foams

et al. 2018

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“…König et al 24,25 synthesized new phosphorus ame-retardant methyl-DOPO in a exible polyurethane foam and then contributed to the gas-phase activity of ame inhibition. Gaan et al 26 and Rao et al 27 synthesized DOPO-based phosphonamidate additives and incorporated them in the polyurethane manufacturing process. The above-mentioned studies indicate that DOPO phosphonamidates exhibit better ame-retardant efficiency than the commercial ame retardants.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of a novel flame retardant based on DOPO derivatives and its application in waterborne polyurethane

Hui

Wang

et al. 2019

RSC Adv.

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“…The figure’s legend denotes the experiment’s timing, which runs from 0 (i.e., the beginning state of suspension) to the final position of suspension at 179 s of centrifugation. There is frequently a linear correlation between settling velocity and RCF [ 43 , 53 ], which lends credence to the idea that the particles are monodisperse and that Stokes’ equation may be utilized to analyze the samples. Overall, it appears that the shape and porosity of the particles may have a significant impact on the settling velocity of the particles [ 43 , 53 ], as will be demonstrated.…”

Section: Resultsmentioning

confidence: 99%

Colloidal and Sedimentation Behavior of Kaolinite Suspension in Presence of Non-Ionic Polyacrylamide (PAM)

Moud

2022

Gels

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Colloidal behavior of kaolinite particles in water was investigated in this manuscript, without and with the addition of a polymer flocculant (non-anionic polyacrylamide (PAM)), using diverse imaging techniques in addition to LUMisizer. The addition of PAM was found to be causing the formation of bridges among particles thus increasing their settling rates to the bottom of the container. To assess the size of flocs and the potential morphology of PAM around particles and their clusters, the state of flocs formation and polymer distribution was analyzed through various microscopical techniques, namely scanning electron microscopy (SEM) and transmission electron microscopy (TEM). SEM and TEM results revealed that, in the absence of PAM, the floc structure of the sediment was loose and irregularly distributed, while the presence of PAM made the sediment structures greatly denser. Later, using LUMisizer, dynamic light scattering (DLS) and the zeta potential of kaolinite, sedimentation, and colloidal behavior of suspension came under scrutiny. Using LUMisizer, the maximum packing and settling rates of the particles were experimentally obtained as roughly 44 vol%; settling rates were estimated in 63–352 µm/s when centrifugal force varied and, using maximum packing values, compressive yield was estimated to vary between 48–94 kPa. The results of this study are instructive in choosing appropriate polymers and operating conditions to settle clay minerals in tailing ponds. Additionally, the maximum packing of kaolinite particles was simulated with spherical particles with varied polydispersity to connect DLS data to the maximum packing values obtained using LUMisizer; the little discrepancy between simulation and experimental values was found to be encouraging.

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Enhanced flame-retardancy and controlled physical properties of flexible polyurethane foams based on a shear-responsive internal network

Abstract: The flame retardancy of FPUFs can be enhanced by the manipulation of the solid-polymer interface chemistry.

Cited by 9 publications

References 45 publications

Some Key Factors Influencing the Flame Retardancy of EDA-DOPO Containing Flexible Polyurethane Foams

Some Key Factors Influencing the Flame Retardancy of EDA-DOPO Containing Flexible Polyurethane Foams

Synthesis of a novel flame retardant based on DOPO derivatives and its application in waterborne polyurethane

Colloidal and Sedimentation Behavior of Kaolinite Suspension in Presence of Non-Ionic Polyacrylamide (PAM)

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