The use of heating microscopy in the study of intumescence in waste catalyst containing polymer systems

Estevão, Luciana R. M.; Nascimento, Regina Sandra Veiga

doi:10.1016/s0141-3910(01)00255-5

Cited by 15 publications

(9 citation statements)

References 18 publications

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“…This method has proved to be a useful experimental technique for performing intumescence studies, since the phenomenon can be observed and monitored continuously in situ [18]. The analyses were carried out in a Leitz heating microscope (Model 1A) using cubic samples with a side of 3 mm, which were heated from 30 to 700…”

Section: Methodsmentioning

confidence: 99%

Effect of clays on the fire-retardant properties of a polyethylenic copolymer containing intumescent formulation

Ribeiro¹,

Estevão

Nascimento³

2008

Science and Technology of Advanced Materials

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Organophilic clay particles were added to a standard intumescent formulation and, since the role of clay expansion or intercalation is still a matter of much controversy, several clays with varying degrees of interlayer distances were evaluated. The composites were obtained by blending the nanostructured clay and the intumescent system with a polyethylenic copolymer. The flame-retardant properties of the materials were evaluated by the limiting oxygen index (LOI), the UL-94 rating and thermogravimetric analysis (TGA). The results showed that the addition of highly expanded clays to the ammonium polyphosphate and pentaerythritol formulation does not significantly increase the flame retardancy of the mixture, when measured by the LOI and UL-94. However, when clays with smaller basal distances were added to the intumescent formulation, a synergistic effect was observed. In contrast, the simple addition of clays to the copolymer, without the intumescent formulation, did not increase the fire retardance of the materials.

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Section: Methodsmentioning

confidence: 99%

Effect of clays on the fire-retardant properties of a polyethylenic copolymer containing intumescent formulation

Ribeiro¹,

Estevão

Nascimento³

2008

Science and Technology of Advanced Materials

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“…The swelling process can be monitored in situ by heating microscopy (Estevão & Nascimento, ). This technique enables the observation not only of modifications in the volume of the specimens as a function of the temperature but also the integrity of the intumescent layer structure at high temperatures.…”

Section: Methodsmentioning

confidence: 99%

“…This technique is widely used in glass and ceramic studies, especially to monitor the sintering of the samples and the formation of metal alloys. However, the FLUMAT research group pioneered the use of this technique in the analysis of intumescent polymers (Estevão & Nascimento, ).…”

Section: Methodsmentioning

confidence: 99%

Microscopy as a tool to investigate the influence of ammonium polyphosphate particle size on the flame retardant properties of polymer composites

Silva

Martins

Estevão

et al. 2019

Microscopy Res & Technique

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The influence of ammonium polyphosphate (APP) particle size on the performance of an intumescent formulation and on the synergistic action of a series of montmorillonite samples with different d‐spacings for the production of flame retardant composites was investigated. The polymer matrix employed was poly(ethylene‐co‐butyl acrylate), EBA 30, and the intumescent formulation consisted of APP and pentaerythritol (PER). After being processed, the composites were submitted to scanning electron microscopy (SEM), thermogravimetric analysis, heating microscopy, and limiting oxygen index tests. The results indicate that the greater interaction between the APP and PER molecules, caused by the increase of the contact area promoted by the reduction of the APP particle size, could favor the esterification reaction between APP423 and PER, allowing the formation of a greater amount of char precursors in shorter period of time. In addition, the montmorillonite d‐spacings had a more pronounced influence on the clays synergistic action with the intumescent formulation containing the APP with smaller particle size. Microscopy has shown to be an important tool to investigate APP particle size effect on the fire retardancy. AFM results enabled the detection of nanometric particles in the sample containing the smallest particle size of APP. SEM micrographs showed that those nanometric particles were better dispersed in the matrix, interacting more effectively with the other components, a factor probably responsible for the superior fire retardancy results. Heating microscopy revealed that the material with smaller APP particle size did show some remaining structure at the temperature of 850°C.

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“…These experimental setups somehow define different scenarios with respect to a real fire and most of flammability and combustion tests, such as UL94, Cone Calorimeter, and Limiting Oxygen Index. The heating source is a furnace [5,6,8,12], and the char residue expansion measurements are performed under controlled temperature [5][6][7][8][9][10]12]. In some cases, the facilities may limit the free expansion of the char residue: indeed, the expansion takes place in a confined space, and the specimens are subject to a normal force so that the char residue is not completely free to expand [5,6].…”

Section: Introductionmentioning

confidence: 99%

An online acquisition method for monitoring the surface growth of flame retardant protective layers

et al. 2015

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SUMMARYThis paper describes the development of a video acquisition system aimed at monitoring the surface growth of flame-retarded polymers during flammability and combustion tests. The system minimizes the disturbances of the flames on the image sensors, thus gathering a video of the material surface. The device continuously records and quantitatively measures the carbonization front growth rate. The apparatus consists of a camera with customized lighting and dedicated software acquiring images of the burning specimen. The UL94 test procedure has been used during the development of the device and as test bed for the apparatus.

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The use of heating microscopy in the study of intumescence in waste catalyst containing polymer systems

Cited by 15 publications

References 18 publications

Effect of clays on the fire-retardant properties of a polyethylenic copolymer containing intumescent formulation

Effect of clays on the fire-retardant properties of a polyethylenic copolymer containing intumescent formulation

Microscopy as a tool to investigate the influence of ammonium polyphosphate particle size on the flame retardant properties of polymer composites

An online acquisition method for monitoring the surface growth of flame retardant protective layers

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