Combination Of Flame Retardants Research Articles

Advancing building fire safety through heat resistant and flame retardant hybrid silicone sealant

Rapid urbanization and population growth have led to a significant transformation in the urban landscape, characterized by the proliferation of high-rise buildings. However, this urban development has brought about new challenges, particularly in terms of fire safety. The escalating risk of disasters, especially fires, underscores the critical importance of implementing effective fire safety measures across all building types, necessitating legislative reforms. Despite their crucial role in ensuring structural integrity, sealants have often been overlooked in building safety standards, resulting in a lack of comprehensive regulations. The research addresses these challenges by focusing on the development of fire-resistant silicone sealants designed to enhance the fire resistance of building materials. These sealants were formulated independently, incorporating three fire retardants and four heat-resistant agents. While metal oxide flame retardants generally exhibited excellent performance, excessive mixing led to surface deformation and reduced workability. Optimal combinations of flame retardants and heat-resistant agents were identified, with the FR2 specimen demonstrating promising fire resistance performance. Full-scale fire performance tests conducted on FR2 revealed a maximum temperature difference of 40.6 °C between heated and unheated surfaces over a 2-h period, indicating high thermal insulation performance. These findings validate the efficacy of the proposed method and offer significant enhancements to building safety, thereby mitigating fire damage in urban environments.

Flame Retardant Combinations with Expandable Graphite/Phosphorus/CuO/Castor Oil in Flexible Polyurethane Foams

A series of flexible polyurethane foams (FPUFs) were prepared with single and different combinations of flame retardants and additives. Expandable graphite (EG), phosphorous polyol (OP), copper (II) oxide (CuO), and/or castor oil (CAS) were added to FPUF during the foam preparation in a one-step process. The purpose of the study is to evaluate the synergistic effects of the flame retardants, additives, and the presence of bio-based content on the mechanical properties, flame retardancy, and smoke behavior of FPUFs. The combination of 10 wt % EG and 5 wt % OP in FPUF significantly improves the char yield. In the cone calorimeter experiment, the char yield is nearly three times higher than that with 10 wt % EG alone. The smoke behavior is additionally evaluated in a smoke density chamber (SDC). Comparing the samples with a single flame retardant, 10 wt % EG in FPUF considerably reduces the amount of smoke released and the emission of toxic gases. Replacing the amount of 10 wt % polyether polyol in FPUF with CAS maintains the physical and mechanical properties and fire behavior and enhances the bio-based content. The presence of 0.1 wt % CuO in FPUF effectively reduces the emission of hydrogen cyanide. As a result, this study proposes a multicomponent flame retardant strategy for FPUF to enhance the biomass content and address the weaknesses in flame retardancy, smoke, and toxic gas emissions. A starting point is disclosed for future product development.

It Takes Two to Tango: Synergistic Expandable Graphite-Phosphorus Flame Retardant Combinations in Polyurethane Foams.

Due to the high flammability and smoke toxicity of polyurethane foams (PUFs) during burning, distinct efficient combinations of flame retardants are demanded to improve the fire safety of PUFs in practical applications. This feature article focuses on one of the most impressive halogen-free combinations in PUFs: expandable graphite (EG) and phosphorus-based flame retardants (P-FRs). The synergistic effect of EG and P-FRs mainly superimposes the two modes of action, charring and maintaining a thermally insulating residue morphology, to bring effective flame retardancy to PUFs. Specific interactions between EG and P-FRs, including the agglutination of the fire residue consisting of expanded-graphite worms, yields an outstanding synergistic effect, making this approach the latest champion to fulfill the demanding requirements for flame-retarded PUFs. Current and future topics such as the increasing use of renewable feedstock are also discussed in this article.

TIN OXIDE DOPPED CaCO3 COATING ON PAPER FOR FLAME RETARDANCY AND PRINTABILITY PROPERTIES

"Valuable papers, such as checks, promissory notes, money or printing papers used in wallpaper laminates, must be resistant to burning. For this reason, different flame retardants are used in papers. However, generally, the flame retardants used negatively affect printability by creating a hydrophobic surface. For this reason, it is thought that the combination of flame retardants with a filler that will positively affect the printability of paper will be more suitable for such printable papers. For this purpose, this work aimed to obtain paper with good printability and delayed ignition properties by using calcium carbonate, which is a good paper filler, and tin oxide, which is a flame retardant. In this study, starch-based paper coating formulations containing calcium carbonate and tin oxide individually and in combination in equal amounts were prepared and applied on office paper. Color, gloss, contact angle and flame retardancy properties of the produced papers were determined using a spectrophotometer, a glossmeter, a goniometer and LOI, respectively. Prints were made on the the obtained papers with the IGT C1 offset test printing machine, and the color and gloss properties of the prints were determined. As a result, it was determined that the flame retardancy properties of the papers were significantly increased with the tin oxide filler, while the combination of calcium carbonate and tin oxide improved both the printability and flame retardancy properties."

Various Combinations of Flame Retardants for Poly (vinyl chloride)

AbstractVarious combinations of zinc borate (ZB), alumina trihydrate (ATH) and magnesium hydroxide (MH) were used to retard the flammability of PVC composite. Flame retardancy of samples were investigated with limiting oxygen index (LOI) test. Further testing was achieved to expose the individual and synergistic effects of flame retardant additives on heat stability, Vicat softening temperature, fusion time, microstructure, mechanical and thermal characteristics. Microstructural and thermal analyses were performed by scanning electron microscopy and TG/DTA respectively. The LOI results showed that, high levels of ZB-ATH combination provided the highest LOI value of 53.4%. Although ZB and its combinations improved the fire performances of composites, they caused a small reduction at tensile strengths. When compared with plain PVC, flame retardant composites had better thermal stability. In addition to the advantages of ZB, when test results were evaluated with a holistic approach ZB-ATH-MH combination was understood to be an effective flame retardant alternative with this research.

Combination of Phosphorous Flame Retardants and Aluminum Trihydrate in Multicomponent EPDM Composites

Ethylene propylene diene monomer (EPDM) rubbers with the flame retardants tris(2‐ethylhexyl)phosphate, ammonium polyphosphate, polyaniline, and aluminum trihydroxide were prepared and analyzed in this study. The homogenous dispersion of the fillers in the rubber matrix was confirmed by scanning electron microscope. To investigate the interplay of the different flame retardants, the flame retardants were varied systematically. The comprehensive study sought combinations of flame retardants that allow high loadings of flame retardants without deterioration of the physical and mechanical properties of the EPDM rubber. The eight EPDM rubbers were investigated via thermogravimetric analysis and pyrolysis gas chromatography coupled with a mass spectrometer (Py‐GC/MS) to investigate the potential synergistic effects. In the Py‐GC/MS experiments, 27 pyrolysis products were identified. Furthermore, UL 94, limiting oxygen index, FMVSS 302, glow wire tests, and cone calorimeter tests were carried out. In the cone calorimeter test the EPDM rubbers R‐1AP and R‐1/2P achieved an increase in residue at flameout of 76% and a reduction in total heat evolved of about 35%. Furthermore, the compounds R‐1AP and R‐1/2P achieved a reduction in MAHRE to about 150 kW m−1, a reduction of over 50% compared to the unprotected rubber R. POLYM. ENG. SCI., 60: 267–280, 2019. © 2019 The Authors. Polymer Engineering & Science published by Wiley Periodicals, Inc. on behalf of Society of Plastics Engineers.

CeO2-dolomite as fire retardant additives on the conventional intumescent coating in steel substrate for improved performance

Multiple combinations of CeO2-Dolomite as fillers and Intumescent Flame Retardant (IFR) ingredients were used to optimize the intumescent coatings designed for I-beam steel substrates. The influenced of fillers and various combinations of flame-retardants on the fire protective performance of the coatings were evaluated using vertical Bunsen burner fire test and various characterization techniques. Formula C and Formula F having 1:1 and 2:2 CeO2-Dolomite ratio, obtained the lowest substrate temperature around 150oC and 150.4oC, respectively after 90 minutes fire exposure. Also, the morphological structures of intumescent char observed by SEM-EDX, demonstrated that Formula C and Formula F stimulated the formation of homogeneous and more compacted surface structure. X-ray photoelectron spectroscopy (XPS) provide the binding energies of C and O constituents, it was observed that [-(C2H4)n-] was the most important free radical as it could promote the formation of aromatic carbon chain in the char surface. Finally, the findings of this study revealed that the selection of appropriate fillers and combinations of flame-retardant ingredients significantly influenced the morphological structure of the char layer, of which, Formula C and Formula F produced a char with higher thermal stability, resulting to a more fire resistive IFR coating during fire exposure.

Comparative study of toxicity for thermoplastic polyurethane and its flame-retardant composites

Toxic product in fire disasters is the most important reason for fire casualties. With wide application of polymer material, the toxic products in fire effluents are getting more and more diversified and complicated. Polyurethane is one of the most widely used materials. In this article, the fire toxicant release has been evaluated for thermoplastic polyurethane (TPU) and its flame-retardant composites. Ammonium polyphosphate (APP), aluminum hydroxide (ATH), and nano-montmorillonite (MMT) were combined into different flame-retardant combinations at certain ratios. Three kinds of flame-retardant combinations (APP-ATH, APP-MMT, and APP-ATH-MMT) were blended to reduce toxicity of TPU. The properties of thermal stability and decomposition were characterized by thermogravimetric analysis (TGA). TGA/infrared spectrometry, static tube furnace, and steady-state tube furnace were used to evaluate the toxic gases, including CO and HCN. Fractional effective dose (FED) was calculated based on the concentrations of CO, CO2, and HCN. The results showed that more than 50% toxicity effect in FED was accounted for HCN. The comprehensive toxicity of TPU was reduced in the samples with APP-ATH and APP-ATH-MMT. The yields of CO, CO2, and O2 consumption were indicated much lower in the samples with APP-ATH-MMT than the other two combinations.

Rapid mass calorimeter as a high-throughput screening method for the development of flame-retarded TPU

The rapid mass calorimeter (RMC) was used as a screening tool based on accelerated fire testing to assess flame-retarded thermoplastic polyurethane (TPU). The reliability of RMC results was proven with the cone calorimeter as reference fire test. The influence of melamine cyanurate (MC) concentration on the fire performance of TPU was investigated, along with some flame-retardant combinations such as MC with aluminium diethylphosphinate (AlPi), aluminium trihydrate (ATH), and melamine polyphosphate (MPP). The two-stage burning behaviour of TPU was investigated in detail; the first stage corresponds mainly to the hard segments' decomposition and has a much lower effective heat of combustion (EHC) than the second stage, in which mainly the soft segments decompose and an intensive liquid pool fire is observed in the cone calorimeter set-up. In addition to fire testing with the cone calorimeter, RMC, and UL 94 flammability tests, the decomposition of the materials was investigated using thermogravimetric analysis coupled with infrared spectrometry (TG–FTIR). TPU/MC/AlPi shows the most promising results, achieving V-0 classification in UL 94 and reducing the extreme peak heat release rate (PHRR) of the liquid pool fire from 3154 kW/m2 to 635 kW/m2. Using MC/AlPi/MPP enhances the latter PHRR reduction further. The decomposition products identified in the gas phase via TG–FTIR reveal specific MC–AlPi–MPP interactions, as they differ from products seen in systems with MC/AlPi or MC/MPP. Correlations between RMC and cone calorimeter results were examined and presented in the final part of the paper. Several characteristics correlate strongly, pointing out that RMC is a reliable high-throughput fire testing method to screen multicomponent flame-retardant solutions in TPU.

Rapid screening test for flame retardation of wood, and its applicability to thermoplastic polymer systems

ABSTRACTA rapid screening process was developed to investigate the flame‐retardant properties of new materials and compositions. Wooden tongue depressors (“sticks”) were coated in solutions/suspensions of compositions of interest and tested in a method similar to that of the UL‐94 vertical burn test. The concentration of additives applied to the wooden sticks, as well as the additive application and drying times influenced the burning performance of the sticks, a useful screening method for testing flame retardants applied to wood products. The most promising combination of flame retardants from the wooden stick tests were then compounded into polyolefins, which were tested according to the UL(94) vertical burn protocol. A strong correlation was found between UL(94) results for low density polyethylene, high density polyethylene and polypropylene, and the wooden stick flammability data. This test, therefore, shows promise as a simple, inexpensive, and rapid way to screen new materials and compositions for flammability. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46602.

Evaluation of Different Flame Retardant Combinations for Core/Shell Structured Wood-Plastic Composites by Using a Cone Calorimeter

The fire retardancy of coextruded wood-plastic composites (WPCs) containing melamine, ammonium polyphosphate (APP), natural graphite, expandable graphite and carbon nanotubes (CNTs) in the shell layer was characterized with a cone calorimeter test. A coextruded composite manufactured without any fire retardant (FR) in the shell layer was used as a reference. The incorporation of different combinations of FRs in the shell layers of WPCs reduced the peak heat release rate by 3-43%, depending on the FR combination. Other studied parameters, such as ignition time, total heat release and mass loss rate were improved after FR systems loading. The best improvement of flammability characteristics was observed with melamine/natural graphite combinations, whereas the melamine/expandable graphite system resulted only in slight improvement of the studied parameters. However, it should be noted that the amount of expandable graphite loading was 2-4 times lower than the amount of natural graphite loadings. Incorporation of 2 wt.% CNTs in the shell layer did not show any significant improvement in the studied parameters. The total smoke release and carbon monoxide production were increased with melamine/APP loading in the shell layer.

Estudo de sistemas retardantes de Chama sem Bromo para ABS

Este trabalho visa estudar e caracterizar o desempenho de aditivos retardantes de chama não bromados em copolímero de ABS. Foram estudadas combinações de retardantes de chama, como: o polifosfato de amônio (APP), a melamina, nanopartículas de dióxido de titânio e argila organicamente modificada com sal quaternário de fosfônio. Os materiais obtidos foram caracterizados por ensaios mecânicos (resistência ao impacto Izod e resistência à tração), análise termogravimétrica (TG), avaliação da morfologia e ensaio de retardância à chama. Os resultados obtidos indicaram uma redução de cerca de 48% na velocidade de propagação da chama dos compósitos com APP/melamina/TiO2/argila organofílica, em relação ao copolímero de ABS puro.

Protection mechanism of a flame-retarded polyamide 6 nanocomposite

Investigations have been performed to determine the causes of the synergistic effect observed when a combination of flame retardants (FR; aluminum phosphinate/melamine polyphosphate) and organomodified montmorillonite (o-MMT) is used in polyamide 6 (PA6). Structures obtained at different stage of degradation in cone calorimeter experiments for the PA6, PA6/FR, PA6/o-MMT, PA6/FR/o-MMT are compared. The evolution of the chemical species formed according to the stages of degradation together with the characterization of the resistance of the char have enabled to elucidate the mechanism of protection involved for PA6/FR/o-MMT. Infrared characterizations have demonstrated that the species formed are degradation products of the components of the formulation that are also observed for PA6/FR and PA6/o-MMT and do not explain the improved performances. However, the structure of the char with clay distinguishes itself with a very specific small closed-cells foamed structure exhibiting an enhanced char strength. A detailed comparison of the mode of protection involved when using FR and a combination of FR/o-MMT when submitted to fire is proposed.

Flame retardancy of thermoplastics polyurethanes

This study compares a wide range of potentially synergistic flame retardant combinations in thermoplastic polyurethanes, applying both additive and reactive formulations. After preliminary screening based on LOI and UL-94 results, the best additive and reactive systems were subjected to detailed (thermogravimetric, cone calorimetric, mechanical and rheological) analysis and were compared to the reference TPU and a flame retarded benchmark TPU system.

Flammability and Mechanical Properties of Sisal Fiber/Polypropylene Composites: Effect of Combination of Flame Retardants

Ammonium polyphosphate (APP) and zinc borate (Zb), as flame retardants were incorporated into sisal fiber/polypropylene (PP) composites. Ratios of APP to Zb were varied. Maleic anhydride grafted polypropylene (MAPP) was used to improve the interfacial adhesion between polypropylene and fillers. Flammability of the composites was examined using a horizontal burning test, a vertical burning test, and a limiting oxygen index test. Morphology and mechanical properties of the composites were also investigated. The composite containing 30 phr of APP and 10 phr of Zb exhibited better flame retardancy than the composites containing other ratios of APP to Zb. The combination of APP and Zb insignificantly changed mechanical properties of the composites. In addition, SEM micrographs of the composites revealed good distribution of flame retardants and sisal fiber in PP matrix.

Flammability, degradation and structural characterization of fibre-forming polypropylene containing nanoclay–flame retardant combinations

We have shown previously that the introduction of nanoclays can reduce the flammability of synthetic fibre-forming polymers like polyamides 6 and 6.6 only if used in conjunction with conventional flame retardants. In this work we report initial studies of the effects of dispersed nanoclays with low concentrations of selected flame retardants introduced into polypropylene on flammability, thermal degradation and X-ray diffraction behaviours. Flame retardants used include ammonium polyphosphate as a conventional char-former and a hindered amine stabiliser known to have flame retarding characteristics in polypropylene.

Flammability parameters of wood tested on a cone calorimeter

The effect of different loads of magnesium hydroxide as flame retardant on the flammability parameters of particleboard was studied. The effect of different flame retardant combinations was also compared. The flammability parameters were measured on a cone calorimeter at the uniform external irradiance of 50 kW m −2 for all modifications. The magnesium hydroxide improved the flammability parameters of particleboard and did not have negative effect on carbon monoxide production. From the different combinations of flame retardants the best retardant effects were measured for the combination of monoammonium phosphate and boric acid.

Action of various flame retardant combinations on the flammability of polypropylene

The flammability and smoke generated by burning of polypropylene is discussed. Alicylic chlorine- and bromine-containing compounds, an aliphatic-aromatic bromine compound, bicyclic thionophosphorinane, and a mixture of ammonium polyphosphate and nitrogen-containing heterocyclic polymers were used as flame retardants (FR). Synergistic and anatagonistic effects were observed by using Sb 2O 3, organotin compounds, zinc borate, talc and ferrocene together with the FR. Flammability was measured by the oxygen index test method (OI) simultaneously with the determination of smoke density. Mass losses caused by burning were also measured. Thermal degradation was studied by thermogravimetry (TG) and derivative thermogravimetry (DTG).

The Effects of Flame Retardant Combinations in PVC-Epoxidised Natural Rubber Miscible Blends: Antimony Trioxide in Combination with Halogen and Non-Halogen Based Additives

Effects of antimony trioxide in combination with halogen and non-halogen based additives in a matrix of PVC/ENR miscible blends were studied for processibility, miscibility of blend components, strength properties, thermal stability, and flammability. Flammability measurements were carried out by limiting oxygen index measurement. The impairments in processibility and strength properties were within tolerable limits. Additive combinations did not alter the miscibility of blend components. Thermal stability was greatly influenced. Synergistic flame retardation of zinc borate with Sb2O3 with and without decabromodiphenyl ether was explained by a vapor phase- condensed phase flame retardation mechanism. The antagonistic effect of phosphorus/antimony was greatly deactivated by a halogen additive and/or zinc borate.