Flame Retardancy of Lightweight Sandwich Composites

This study proposes an innovative solution to flame-retard a sandwich composite made of unsaturated polyester resin, glass fibre skins and polyester nonwoven core material. The strategy uses the core material as flame-retardant carrier, while the resin is also flame-retarded with aluminum trihydroxide (ATH). A screening of the fire-retardant performances of the core materials, covered with different types of phosphorous flame-retardant additives (phosphate, phosphinate, phosphonate), was performed using cone calorimetry. The best candidate was selected and evaluated in the sandwich panel. Great performances were obtained with ammonium polyphosphate (AP422) at 262 g/m2. The core material, when tested alone, did not ignite, and when used in the laminate, improved the fire behaviour by decreasing the peak of heat release rate (pHRR) and the total heat release (THR): the second peak in HRR observed for the references (full glass monolith and sandwich with the untreated core) was suppressed in this case. This improvement is attributed to the interaction occurring between the two FR additives, which leads to the formation of aluminophosphates, as shown using Electron Probe Micro-Analysis (EPMA), X-Ray Diffraction (XRD) and solid-state 31P Nuclear Magnetic Resonance (NMR). The influence of the FR add-on on the core, as well as the ATH loading in the matrix, was studied separately to optimize the material performances in terms of smoke and heat release. The best compromise was obtained using AP422 at 182 g/m2 and 160 phr of ATH.

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Flame-retardancy and smoke suppression characteristics of bamboo impregnated with silicate-intercalated calcium aluminum hydrotalcates

BioResources ◽

10.15376/biores.16.1.1311-1324 ◽

2020 ◽

Vol 16 (1) ◽

pp. 1311-1324

Author(s):

Yating Hua ◽

Chungui Du ◽

Huilong Yu ◽

Ailian Hu ◽

Rui Peng ◽

...

Keyword(s):

Heat Release ◽

Flame Retardant ◽

Flame Retardancy ◽

Flame Retardants ◽

Mass Loss Rate ◽

Fire Retardant ◽

Smoke Suppression ◽

Cone Calorimetry ◽

Before And After ◽

Carbon Monoxide Yield

Flame-retardant silicate-intercalated calcium aluminum hydrotalcites (CaAl-SiO3-LDHs) were synthesized to treat bamboo for retardancy, to overcome the bamboo’s flammability and reduce the production of toxic smoke during combustion. The microstructure, elemental composition, flame retardancy, and smoke suppression characteristics of the bamboo before and after the fire-retardant treatment with different pressure impregnation were studied using a scanning electron microscope (SEM), elemental analysis (EDX), and cone calorimetry. It was found that CaAl-SiO3-LDHs flame retardants can effectively fill and cover the cell wall surface and the cell cavity of bamboo without damaging the microstructure. As compared to the non-flame-retardant bamboo, the heat release rate (HRR) of the CaAl-SiO3-LDHs flame-retardant bamboo was significantly reduced, the total heat release (THR) decreased by 31.3%, the residue mass increased by 51.4%, the time to ignition (TTI) delay rate reached 77.8%, the mass loss rate (MLR) decreased, and the carbon formation improved. Additionally, as compared to the non-flame-retardant bamboo, the total smoke release (TSR) of the CaAl-SiO3-LDHs flame-retardant bamboo decreased by 38.9%, and the carbon monoxide yield (YCO) approached zero. Thus, the CaAl-SiO3-LDHs flame-retardant bamboo has excellent flame-retardancy and smoke suppression characteristics.

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Chain Extension and Synergistic Flame-Retardant Effect of Aromatic Schiff Base Diepoxide on Polyamide 6/Aluminum Diethylphosphinate Composites

Materials ◽

10.3390/ma12142217 ◽

2019 ◽

Vol 12 (14) ◽

pp. 2217 ◽

Cited By ~ 2

Author(s):

Tianxiang Liang ◽

Jianan Cai ◽

Shumei Liu ◽

Hualin Lai ◽

Jianqing Zhao

Keyword(s):

Schiff Base ◽

Flame Retardant ◽

Flame Retardants ◽

Polyamide 6 ◽

Chain Extension ◽

Cone Calorimetry ◽

The Matrix ◽

Flame Retarded ◽

Ul 94 ◽

Synergistic Flame Retardant

A way to suppress the deterioration in mechanical properties of polyamide 6 (PA6) is required, especially with high loading of flame retardants in the matrix. In this study, a novel aromatic Schiff base diepoxide (DES) was synthesized. It exhibited an efficient chain extension effect on PA6 and a synergistic flame-retardant effect with aluminum diethylphosphinate (AlPi) for PA6. The PA6 composite with 16 wt.% AlPi only passed UL-94 V-0 rating at 1.6 mm thickness, while the combination of 1.5 wt.% DES with 13 wt.% AlPi induced PA6 to achieve a UL-94 V-0 rating at 0.8 mm thickness. The tensile, flexural, and Izod notched impact strengths were increased by 16.2%, 16.5%, and 24.9%, respectively, compared with those of V-0 flame-retarded PA6 composites with 16 wt.% AlPi. The flame-retarded mechanism of PA6/AlPi/DES was investigated by cone calorimetry and infrared characterization of the char residues and pyrolysis products. These results showed that DES had a synergistic effect with AlPi in condensed-phase flame retardation by promoting the production of aluminum phosphorus oxides and polyphosphates in the char residues.

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Mechanically Sustainable Starch-Based Flame-Retardant Coatings on Polyurethane Foams

Polymers ◽

10.3390/polym13081286 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1286

Author(s):

Kyung-Who Choi ◽

Jun-Woo Kim ◽

Tae-Soon Kwon ◽

Seok-Won Kang ◽

Jung-Il Song ◽

...

Keyword(s):

Heat Release ◽

Flame Retardant ◽

Coating Layer ◽

Real Life ◽

Polyurethane Foams ◽

Layer By Layer ◽

Toxic Substances ◽

Cone Calorimetry ◽

Coating Agent ◽

Cone Calorimeter Test

The use of halogen-based materials has been regulated since toxic substances are released during combustion. In this study, polyurethane foam was coated with cationic starch (CS) and montmorillonite (MMT) nano-clay using a spray-assisted layer-by-layer (LbL) assembly to develop an eco-friendly, high-performance flame-retardant coating agent. The thickness of the CS/MMT coating layer was confirmed to have increased uniformly as the layers were stacked. Likewise, a cone calorimetry test confirmed that the heat release rate and total heat release of the coated foam decreased by about 1/2, and a flame test showed improved fire retardancy based on the analysis of combustion speed, flame size, and residues of the LbL-coated foam. More importantly, an additional cone calorimeter test was performed after conducting more than 1000 compressions to assess the durability of the flame-retardant coating layer when applied in real life, confirming the durability of the LbL coating by the lasting flame retardancy.

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Damage behavior of potting materials in sandwich composites with pinned joints

Science and Engineering of Composite Materials ◽

10.1515/secm-2013-0176 ◽

2015 ◽

Vol 22 (5) ◽

Cited By ~ 1

Author(s):

Cesim Atas ◽

Alper Basmaci

Keyword(s):

Core Material ◽

Sandwich Composite ◽

Composite Panels ◽

Sandwich Composites ◽

Resin Infusion ◽

Damage Behavior ◽

Mechanical Joints ◽

The Core ◽

Bottom Face ◽

Infusion Technique

AbstractThe damage behavior of the potting materials around a pinhole, being used in the mechanical joints of sandwich composites, is investigated experimentally. The sandwich composite panels used in the tests were manufactured by the vacuum-assisted resin infusion technique. Each of the top and bottom face sheets of the panels consisted of two woven E-glass/epoxy layers. As the core material, PVC foam (AIREX

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Development of Inherently Flame—Retardant Phosphorylated PLA by Combination of Ring-Opening Polymerization and Reactive Extrusion

Materials ◽

10.3390/ma13010013 ◽

2019 ◽

Vol 13 (1) ◽

pp. 13 ◽

Cited By ~ 1

Author(s):

Rosica Mincheva ◽

Hazar Guemiza ◽

Chaimaa Hidan ◽

Sébastien Moins ◽

Olivier Coulembier ◽

...

Keyword(s):

Heat Release ◽

Flame Retardant ◽

Ring Opening ◽

Coupling Reaction ◽

Reactive Extrusion ◽

Ring Opening Polymerization ◽

Hexamethylene Diisocyanate ◽

Cone Calorimetry ◽

Loss Cone ◽

Ul 94

In this study, a highly efficient flame-retardant bioplastic poly(lactide) was developed by covalently incorporating flame-retardant DOPO, that is, 9,10-dihydro-oxa-10-phosphaphenanthrene-10-oxide. To that end, a three-step strategy that combines the catalyzed ring-opening polymerization (ROP) of L,L-lactide (L,L-LA) in bulk from a pre-synthesized DOPO-diamine initiator, followed by bulk chain-coupling reaction by reactive extrusion of the so-obtained phosphorylated polylactide (PLA) oligomers (DOPO-PLA) with hexamethylene diisocyanate (HDI), is described. The flame retardancy of the phosphorylated PLA (DOPO-PLA-PU) was investigated by mass loss cone calorimetry and UL-94 tests. As compared with a commercially available PLA matrix, phosphorylated PLA shows superior flame-retardant properties, that is, (i) significant reduction of both the peak of heat release rate (pHRR) and total heat release (THR) by 35% and 36%, respectively, and (ii) V0 classification at UL-94 test. Comparisons between simple physical DOPO-diamine/PLA blends and a DOPO-PLA-PU material were also performed. The results evidenced the superior flame-retardant behavior of phosphorylated PLA obtained by a reactive pathway.

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Role of Copper Oxide on Epoxy Coatings with New Intumescent Polymer-Based Fire Retardant

Molecules ◽

10.3390/molecules25245978 ◽

2020 ◽

Vol 25 (24) ◽

pp. 5978

Author(s):

Riyazuddin ◽

Samrin Bano ◽

Fohad Mabood Husain ◽

Jamal Akhter Siddique ◽

Khadijah H. Alharbi ◽

...

Keyword(s):

Copper Oxide ◽

Heat Release ◽

Flame Retardant ◽

Cone Calorimeter ◽

Elevated Temperatures ◽

Fire Retardant ◽

Intumescent Flame Retardant ◽

Gravimetric Analysis ◽

Sem Images ◽

Major Drawback

Epoxy resins (EP) have been used as a thermos-setting material in the field of coating, casting, bonding agent, and laminating. However, a major drawback associated with its use is the lack of good flaming properties, and it is responsible for heavy smoke along with hazardous gases considerably limiting its uses in various fields. In this study, N-ethanolamine triazine-piperizine, a melamine polymer (ETPMP), was established as a new charring-foaming agent and was successfully synthesized with ethanolamine, piperizine, cyanuric chloride, and melamine as precursor molecules via the nucleophilic substitution reaction method. Elemental analysis and Fourier transform infrared (FTIR) spectroscopy analysis were applied to approve the synthesis of ETPMP and confirmation of its structure and characterization. The epoxy coating of intumescent flame retardant (IFR) was equipped by introducing ETPMP, ammonium polyphosphate (APP), and copper oxide (CuO) in multiple composition ratios. CuO was loaded at various amounts into the IFR-coating system as a synergistic agent. The synergistic action of CuO on IFR coatings was scientifically examined by using different analytical tests such as vertical burning test (UL-94V), limited oxygen index (LOI), thermal gravimetric analysis (TGA), cone calorimeter, and scanning electron microscope (SEM). The results showed that small changes in the amount of CuO expressively amplified the LOI results and enhanced the V-0 ratings in the UL-94V test. The TGA data clearly demonstrate that the inclusion of CuO can transform the thermal deprivation behavior of coatings with a growing char slag proportion with elevated temperatures. Information from cone calorimeter data affirmed that CuO can decrease the burning factors by total heat release (THR) together with peak heat release rate (PHRR). The SEM images indicated that CuO can enrich the power and compression of the intumescent char that restricts the movement of heat and oxygen. Our results demonstrate a positive influence of CuO on the epoxy-headed intumescent flame retardant coatings.

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Valorization of Industrial Lignin as Biobased Carbon Source in Fire Retardant System for Polyamide 11 Blends

Polymers ◽

10.3390/polym11010180 ◽

2019 ◽

Vol 11 (1) ◽

pp. 180 ◽

Cited By ~ 6

Author(s):

Neeraj Mandlekar ◽

Aurélie Cayla ◽

François Rault ◽

Stéphane Giraud ◽

Fabien Salaün ◽

...

Keyword(s):

Thermal Stability ◽

Condensed Phase ◽

Flame Retardants ◽

Fire Behavior ◽

Fire Retardant ◽

Ternary Blends ◽

Cone Calorimetry ◽

Polyamide 11 ◽

Twin Screw ◽

Flame Retarded

In this study, two different types of industrial lignin (i.e., lignosulphonate lignin (LL) and kraft lignin (DL)) were exploited as charring agents with phosphorus-based flame retardants for polyamide 11 (PA11). The effect of lignins on the thermal stability and fire behavior of PA11 combined with phosphinate additives (namely, aluminum phosphinate (AlP) and zinc phosphinate (ZnP)) has been studied by thermogravimetric analysis (TGA), UL 94 vertical flame spread, and cone calorimetry tests. Various blends of flame retarded PA11 were prepared by melt process using a twin-screw extruder. Thermogravimetric analyses showed that the LL containing ternary blends are able to provide higher thermal stability, as well as a developed char residue. The decomposition of the phosphinates led to the formation of phosphate compounds in the condensed phase, which promotes the formation of a stable char. Flammability tests showed that LL/ZnP ternary blends were able to achieve self-extinction and V-1 classification; the other formulations showed a strong melt dripping and higher burning. In addition to this, cone calorimetry results showed that the most enhanced behavior was found when 10 wt % of LL and AlP were combined, which strongly reduced PHRR (−74%) and THR (−22%), due to the interaction between LL and AlP, which not only promotes char formation but also confers the stability to char in the condensed phase.

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Development of Biodegradable Flame-Retardant Bamboo Charcoal Composites, Part I: Thermal and Elemental Analyses

Polymers ◽

10.3390/polym12102217 ◽

2020 ◽

Vol 12 (10) ◽

pp. 2217 ◽

Cited By ~ 2

Author(s):

Shanshan Wang ◽

Liang Zhang ◽

Kate Semple ◽

Min Zhang ◽

Wenbiao Zhang ◽

...

Keyword(s):

Heat Release ◽

Flame Retardant ◽

Residue Analysis ◽

Fire Retardant ◽

Protective Layer ◽

Growth Index ◽

Raw Material ◽

Bamboo Charcoal ◽

Limiting Oxygen Index ◽

Plastic Composite

In this study, bamboo charcoal (BC) was used as a substitute filler for bamboo powder (BP) in a lignocellulose-plastic composite made from polylactic acid (PLA), with aluminum hypophosphite (AHP) added as a fire retardant. A set of BC/PLA/AHP composites were successfully prepared and tested for flame-retardancy properties. Objectives were to (a) assess compatibility and dispersibility of BC and AHP fillers in PLA matrix, and (b) improve flame-retardant properties of PLA composite. BC reduced flexural properties while co-addition of AHP enhanced bonding between PLA and BC, improving strength and ductility properties. Adding AHP drastically reduced the heat release rate and total heat release of the composites by 72.2% compared with pure PLA. The formation of carbonized surface layers in the BC/PLA/AHP composites effectively improved the fire performance index (FPI) and reduced the fire growth index (FGI). Flame-retardant performance was significantly improved with limiting oxygen index (LOI) of BC/PLA/AHP composite increased to 31 vol%, providing a V-0 rating in UL-94 vertical flame test. Adding AHP promoted earlier initial thermal degradation of the surface of BC/PLA/AHP composites with a carbon residue rate up to 40.3%, providing a protective layer of char. Further raw material and char residue analysis are presented in Part II of this series.

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Combustion properties and pyrolysis kinetics of flame-retardant polyurethane elastomers

Journal of Thermoplastic Composite Materials ◽

10.1177/0892705715598361 ◽

2016 ◽

Vol 30 (2) ◽

pp. 255-272 ◽

Cited By ~ 4

Author(s):

Xilei Chen ◽

Lili Huo ◽

Jianbo Liu ◽

Chuanmei Jiao ◽

Shaoxiang Li ◽

...

Keyword(s):

Heat Release ◽

Flame Retardant ◽

Pyrolysis Kinetics ◽

Cone Calorimetry ◽

Polyurethane Elastomers ◽

Conversion Rates ◽

Combustion Properties ◽

Peak Heat Release Rate ◽

Fwo Method ◽

Kinetics Of

Flame-retardant polyurethane elastomers (PUEs) have been prepared using trichloroethyl phosphate (TCEP) as flame retardant. The combustion performances and thermal decomposition properties of PUEs were studied using cone calorimetry test and thermogravimetric analysis, respectively. Kissinger method and Flynn–Wall–Ozawa (FWO) method were adopted to discuss the pyrolysis kinetics of PUEs. The experimental results showed that TCEP has good flame-retardant effect for PUE. With the increase of TCEP, the peak heat release rate and total heat release values decrease. A good diagram of linear regression can be obtained from both Kissinger and FWO methods. The activation energy values of flam- retardant PUE can be calculated from FWO method at different conversion rates.

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Infrared Analysis on Pyrolysis Products of Flame Retardant Rigid Polyurethane Foam

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1033-1034.900 ◽

2014 ◽

Vol 1033-1034 ◽

pp. 900-906

Author(s):

Ze Jiang Zhang ◽

Li Jun Li ◽

Feng Li ◽

Jin He ◽

Zi Qiong Gan

Keyword(s):

Flame Retardant ◽

Polyurethane Foam ◽

Magnesium Hydroxide ◽

Hydrogen Cyanide ◽

Flame Retardants ◽

Fire Retardant ◽

Infrared Analysis ◽

Antimony Trioxide ◽

Stretching Vibration ◽

Flame Retarded

Infrared spectra of the pyrolysis gases of polyurethane foam flame retarded by MPOP, MP, MC, magnesium hydroxide, or antimony trioxide flame retardants was analyzed online by FTIR method. At 600°C, the polyurethane foam flame retarded by MPOP, MP, MC, magnesium hydroxide or antimony trioxide flame retardants released more hydrogen cyanide than the pure polyurethane foam, proved that the MPOP, MP, MC and magnesium hydroxide flame retardants could change the law that the polyurethane released hydrogen cyanide. At 600 °C, the peak of C=O stretching vibration at 1730cm-1did not appear for the flame-retardant polyurethane, indicating that the flame retardants can make the polyurethane rapidly carbonize and the fewer C=O intermediate was produced. The absorbent peaks of the fire-retardant samples at 1604cm-1, 1538 cm-1, 1250 to 1230 cm-1and 1450cm-1implied that the flame retardants could delay the oxidative decomposition of the polyurethane component at 600 °C, so that more components may be carbonized. When increasing the pyrolysis temperature, the perlite would make polyurethane foam release fewer hydrogen cyanide.

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