Intumescent ethylene-vinyl acetate copolymer: Reaction to fire and mechanistic aspects

Bourbigot, Serge; Sarazin, Johan; Samyn, Fabienne; Jimenez, Maude

doi:10.1016/j.polymdegradstab.2019.01.029

Cited by 38 publications

(39 citation statements)

References 28 publications

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“…Indeed, EG has a physical "worm" expansion due to the expansion of graphite, caused by the sublimation of inserted compounds trapped between the graphite layers. [12][13][14][15] On the opposite, ATH dehydrates endothermally upon heating coupled with a dilution effect (water evolution into the gas phase) and the formation of ceramic-like residue (alumina) acting as protective layer. 16 Four materials were prepared ( Table 1).…”

Section: Processingmentioning

confidence: 99%

Additive manufacturing of fire‐retardant ethylene‐vinyl acetate

Geoffroy

Samyn

Jimenez

et al. 2019

Polymers for Advanced Techs

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Thermocompression (with also extrusion and injection molding) is a classical polymer shaping manufacturing, but it does not easily allow designing sophisticated shapes without using a complex mold, on the contrary to 3D printing (or polymer additive manufacturing), which is a very flexible technique. Among all 3D printing techniques, fused deposition modeling is of high potential for product manufacturing, with the capability to compete with conventional polymer processing techniques. This is a quite low cost 3D printing technique, but the range of filaments commercially available is limited. However, in some specific 3D printing processes, no filaments are necessary. Polymers pellets feed directly the printing nozzle allowing to investigate many polymeric matrices with no commercial limitation. This is of high interest for the design of flame‐retarded materials, but literature is scarce in that field. In this paper, a comparison between thermocompression and 3D printing processes was performed on both neat ethylene‐vinyl acetate (EVA) copolymer and EVA flame retarded with aluminum triHydroxyde (ATH) containing different loadings (30 or 65 wt%) and with expandable graphite (EG), ie, EVA/ATH (30 wt%), EVA/ATH (65 wt%), and EVA/EG (10 wt%), respectively. Morphological comparisons, using microscopic and electronic microprobe analyses, revealed that 3D printed plates have lower apparent density and higher porosity than thermocompressed plate. The fire‐retardant properties of thermocompressed and 3D printed plates were then evaluated using mass loss calorimeter test at 50 kW/m2. Results highlight that 3D printing can be used to produce flame‐retardant systems. This work is a pioneer study exploring the feasibility of using polymer additive manufacturing technology for designing efficient flame‐retarded materials.

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Section: Processingmentioning

confidence: 99%

Additive manufacturing of fire‐retardant ethylene‐vinyl acetate

Geoffroy

Samyn

Jimenez

et al. 2019

Polymers for Advanced Techs

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“…These products blast off the graphite flakes and an entangled network of graphite worms is formed at the F o r P e e r R e v i e w surface of the material. 23 Nevertheless, the efficiency of this physical intumescence depends on expansion characteristics of EG, in particular the temperature at which the expansion begins. That is why the fire behavior of polypropylene blended with 10wt% EG was tested with five commercial EGs presenting different expansion temperatures (Table 1).…”

Section: Selection Of the Expandable Graphitementioning

confidence: 99%

Intumescent polypropylene: Interactions between physical and chemical expansion

et al. 2019

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To decrease the reaction to fire of a highly flammable plastic, polypropylene (PP), the concept of intumescence was applied. Two intumescent systems were designed, based on different mechanisms: physical expansion with expandable graphite (EG) and chemical expansion with modified ammonium polyphosphate (AP). Fire behavior of PP containing EG, AP or an AP/EG mixture with a total loading of 10wt% was evaluated by cone calorimetry at 35 kW.m-2. Thermocouples allowed measuring the temperature at the backside or inside samples over time and evaluating the thermal barrier of these intumescent materials. Two grades of AP (difference in composition) and several grades of EG (difference in expansion characteristics) were compared. Mixing AP and EG does not create a synergistic effect in studied conditions. Contrarily, the incorporation of small amount of EG in PP-AP modifies heat transfer in the coating, creating a strong anisotropy. Graphite worms are trapped vertically into the expanded AP, which increases the transverse heat conductivity (lower efficiency of the thermal barrier) and decreases the fire performance. This phenomenon disappears in thicker specimens. While a higher expansion volume of graphite worms improves fire performances of PP with only small amount of EG (1wt%), this effect is not noticeable with AP/EG mixtures.

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“…The literature presents the study of the influence of the intumescent mixture of APP/MA/PE on an increase in the flammability of co-polymers of the EVA [17,18] and SA types [19,20]. However, the results of these works do not make it possible to predict the firefighting efficiency of the studied polymers as a part of intumescent coatings.…”

Section: Literature Review and Problem Statementmentioning

confidence: 99%

Comparison of fire resistance of polymers in intumescent coatings for steel structures

Кalafat

Taran

Plavan

et al. 2020

EEJET

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Thermal destruction of fire-retardant intumescent coating of the composition of ammonium polyphosphate (APP)/melamine (MA)/pentaerythrite (PE)/titanium oxide (TiO 2)/polymer, which can be applied for fire protection of steel structures, was studied. The influence of polymers of different nature-ethylene-vinyl acetate (EVA), vinyl acetate versatate (VAVV), styrene acrylates, and vinyl toluene acrylate on the processes of formation of a coke layer and fire-retardant effectiveness of appropriate coatings was determined. Chemical transformations of polymers EVA and styrene acrylate in the intumescent system of ARR/MA/ PE/TiO 2 in the temperature range of 200-800 °С were studied. It was established that the processes of the thermal destruction of vinyl acetate polymer are more harmonized with chemical reactions of the components of the intumescent system than similar processes for acrylate aromatic polymers. Thermal-oxidation destruction of intumescent compositions at the temperatures of 200-800 °С was explored. It was shown that basic chemical processes with polymers of EVA and VAVV begin after 300 °С and flow in the temperature range of 350-600 °С. It was found that the noticeable degradation of the carbon-phosphorus frame of intumescent compositions with styrene acrylate polymers begins at 450 °С, which is almost by 150 °С below the temperature of degradation of the compositions containing vinyl acetate binders. The conducted fire tests demonstrate that intumescent compositions with the use of acrylate aromatic polymers are more effective at the low coating thickness in ensuring the fire resistance boundary of 30 min. In order to ensure higher values of fire resistance, it is necessary to use intumescent coatings containing vinyl acetate co-polymers as the polymer component. The study of the impact of polymers of intumescent coatings on the boundary of fire resistance of steel structures has scientific and practical significance for the development of differentiated fire protection means, oriented to the given class of fire resistance. Fire-retardant intumescent compositions examined in this study can be used as the basis for the formulations of materials for fire protection of building structures under conditions of a standard fire

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Intumescent ethylene-vinyl acetate copolymer: Reaction to fire and mechanistic aspects

Cited by 38 publications

References 28 publications

Additive manufacturing of fire‐retardant ethylene‐vinyl acetate

Additive manufacturing of fire‐retardant ethylene‐vinyl acetate

Intumescent polypropylene: Interactions between physical and chemical expansion

Comparison of fire resistance of polymers in intumescent coatings for steel structures

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