Crespo et al 2018b - Revision history

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Scipediacontent: Scipediacontent moved page Draft Content 464980580 to Crespo et al 2018b

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Scipediacontent moved page Draft Content 464980580 to Crespo et al 2018b

Scipediacontent: Created page with "== Abstract == This work presents a comparison in the production of electrical conductivity polyester resins by doping it with two types of carbonous fillers; carbon nanotube..."

2022-03-31T15:43:47Z

Created page with "== Abstract == This work presents a comparison in the production of electrical conductivity polyester resins by doping it with two types of carbonous fillers; carbon nanotube..."

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== Abstract ==

This work presents a comparison in the production of electrical conductivity polyester resins by doping it with two types of carbonous fillers; carbon nanotubes (CNT) and carbon black (CB). These polyester resins are used to obtain electrical conductivity powder gel coat. This type of coating reduces cycle times in the manufacture of composites due to the fact that significantly decrease curing time of the gel coat and eliminate secondary operations for the application of the final coating in the composite.
Electrical conductivity with different fillers content and percolation thresholds obtained in the simulation phase are detailed. The results obtained in the simulation are validated at the pilot plant level taking into account the influence of the loading percentage on the resin processing. Finally, a comparison between the results obtained with the different percentage of CNT and CB is made.
The results of the simulation show that the value of the percolation threshold is much lower in the case of CNT (about 3% in the case of CNT versus 35% in the case of CB). The experimental results indicate the strong dependence of the electrical properties on the production process obtaining variations of up to two orders of magnitude in the experimental results using the same percentage of CNT but different type of polyester resin.

== Full document ==
<pdf>Media:Draft_Content_464980580native-articles-116.pdf</pdf>

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 Different samples were obtained with three different types of unsatured polyester resins and two different types of carbonous fillers; CNT and CB. Due to processing problems, mainly high viscosity of the mixture, the maximum quantity of CNT that can be incorporated in the electrically conductive powder gel coat was 3% and the maximum quantity of CB was 15%. According to this, the samples obtained were represented in <span id='cite-_Ref481655483'></span>[[#_Ref481655483|table 1]].
-<div id="_Ref481655483" class="center" style="width: auto; margin-left: auto; margin-right: auto;">[[File:Crespo_et_al_2018b-image15.png|centre|657x657px]]<span style="text-align: center; font-size: 75%;">'''Table 1. '''Experimental samples obtained</span></div>
+<div id="_Ref481655483" class="center" style="width: auto; margin-left: auto; margin-right: auto;">[[File:Crespo_et_al_2018b-image15.png|centre|657x657px]]
 Formulation with Tg value below 40 <sup>o</sup>C are rejected due to the fact that this parameter is related to storage stability and these samples will be not suitable for industrial applications. From processing point of view, formulations containing resin Y are the ones that have a better performance (viscosity, temperature during processing, laminate obtained after extrusion...).

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 The percolation threshold of the different conductive fillers was simulated to validate the results obtained in extrusion trials. Electrical conductivity of unsaturated polyester resin was simulated with Digimat-FE software, to complete the simulation different parameters were defined such as microestructure definition, the mesh or voltage gradient. <span id='cite-_Ref481654527'></span>[[#_Ref481654527|Figure 2]] is a graphic representation of the methodology employed.
 <div id="_Ref481654527" class="center" style="width: auto; margin-left: auto; margin-right: auto;">
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 Simulation results for other percentages of CB between 15 and 60% of CB were obtained to determine percolation threshold. The conductivity values of the Digimat-FE simulation were represented versus the carbon black content in order to visually analyze the optimum carbon black content for polyester (see <span id='cite-_Ref481653426'></span>[[#_Ref481653426|figure 9]]). The optimum carbon black content is 40% as the conductivity dramatically improves from 35% to 40%. The interconnections between carbon black particles appear at this percentage increasing the conductivity in three orders of magnitude.
+[[File:Crespo_et_al_2018b-image12.jpeg|centre|600x600px]]
-[[Image:Crespo_et_al_2018b-image12.jpeg|600px]]
 <div id="_Ref481653426" class="center" style="width: auto; margin-left: auto; margin-right: auto;">
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 <div id="_Ref481655249" class="center" style="width: auto; margin-left: auto; margin-right: auto;">
 <span style="text-align: center; font-size: 75%;">'''Figure 10. '''UP - 1% CNT system simulation results.</span></div>
+[[File:Crespo_et_al_2018b-image14-c.png|centre]]
-[[Image:Crespo_et_al_2018b-image14-c.png|600px]]
 <div id="_Ref481585347" class="center" style="width: auto; margin-left: auto; margin-right: auto;">
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 Different samples were obtained with three different types of unsatured polyester resins and two different types of carbonous fillers; CNT and CB. Due to processing problems, mainly high viscosity of the mixture, the maximum quantity of CNT that can be incorporated in the electrically conductive powder gel coat was 3% and the maximum quantity of CB was 15%. According to this, the samples obtained were represented in <span id='cite-_Ref481655483'></span>[[#_Ref481655483|table 1]].
-<div id="_Ref481655483" class="center" style="width: auto; margin-left: auto; margin-right: auto;">
+<div id="_Ref481655483" class="center" style="width: auto; margin-left: auto; margin-right: auto;">[[File:Crespo_et_al_2018b-image15.png|centre|657x657px]]<span style="text-align: center; font-size: 75%;">'''Table 1. '''Experimental samples obtained</span></div>
-<span style="text-align: center; font-size: 75%;">'''Table 1. '''Experimental samples obtained.</span>''' [[Image:Crespo_et_al_2018b-image15.png|600px]] '''</div>
 Formulation with Tg value below 40 <sup>o</sup>C are rejected due to the fact that this parameter is related to storage stability and these samples will be not suitable for industrial applications. From processing point of view, formulations containing resin Y are the ones that have a better performance (viscosity, temperature during processing, laminate obtained after extrusion...).
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 <div id="_Ref481656096" class="center" style="width: auto; margin-left: auto; margin-right: auto;">
-<span style="text-align: center; font-size: 75%;">'''Table 2. '''Electrical conductivity (S/cm) - UP resin – 3% CNT. Experimental results.</span></div>
+<span style="text-align: center; font-size: 75%;">'''Table 2. '''Electrical conductivity (S/cm) - UP resin – 3% CNT. Experimental results</span></div>
 <div class="center" style="width: auto; margin-left: auto; margin-right: auto;">
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 As it is illustrated in <span id='cite-_Ref481656096'></span>[[#_Ref481656096|table 2]] and in <span id='cite-_Ref481659574'></span>[[#_Ref481659574|figure 12]], values obtained differ by to two orders of magnitude. This can be explained due to processing changes according to the type of resin employed having a strong influence in final electrical path in the composite.
+[[File:Crespo_et_al_2018b-chart1.svg|centre|600x600px]]
-[[Image:Crespo_et_al_2018b-chart1.svg|600px]]
 <div id="_Ref481659574" class="center" style="width: auto; margin-left: auto; margin-right: auto;">

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+<span id="_GoBack"></span>
-−
-<div class="center" style="width: auto; margin-left: auto; margin-right: auto;">
-A. Crespo, B. Monje, R. Llorens,</div>
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-<div class="center" style="width: auto; margin-left: auto; margin-right: auto;">
-S. Viamonte, N. Lardiés.</div>
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-<div class="center" style="width: auto; margin-left: auto; margin-right: auto;">
-<span style="text-align: center; font-size: 75%;">AIMPLAS, Calle Gustave Eiffel, 4. 46980 Paterna. Valencia, ESPAÑA</span></div>
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-{| style="width: 87%;border-collapse: collapse;"
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-|  colspan='2'  style="vertical-align: top;"|<big>Propiedades eléctricas en resinas de poliéster: comparativa del uso de nanotubos de carbono (CNT) y negro de carbono (CB)</big>
-|-
-|  style="border-bottom: 1pt solid black;vertical-align: top;"|<span style="text-align: center; font-size: 75%;"> [[Image:Crespo_et_al_2018b-image1.png|54px]] </span>
-|  style="vertical-align: top;"|
-|-
-|  style="border-top: 1pt solid black;border-bottom: 1pt solid black;vertical-align: top;"|<span style="text-align: center; font-size: 75%;">Historia del artículo:</span>
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-<span style="text-align: center; font-size: 75%;">Recibido 5 de Mayo 2017</span>
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-<span style="text-align: center; font-size: 75%;">En la versión revisada 5 de Mayo 2017</span>
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-<span style="text-align: center; font-size: 75%;">Aceptado 31 de Mayo 2017</span>
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-<span style="text-align: center; font-size: 75%;">Accesible online 21 de Junio 2017 </span>
-|  rowspan='4' style="vertical-align: top;"|<span style="text-align: center; font-size: 75%;">Este trabajo presenta una comparativa en la obtención de resinas de poliéster con propiedades de conductividad eléctrica mediante el dopaje de las mismas con dos tipos de carga carbonosas: nanotubos de carbono (CNT) y negro de carbono (CB). Estas resinas se utilizan en la obtención de un gel coat en polvo con propiedades de conductividad eléctrica. Este tipo de recubrimiento permite reducir los tiempos de ciclo en la fabricación de composites disminuyendo sensiblemente el tiempo de curado del gel coat y eliminando operaciones secundarias para la aplicación de la capa final de recubrimiento de la pieza. </span>
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-<span style="text-align: center; font-size: 75%;">A lo largo del documento se detallan los valores de conductividad eléctrica y los umbrales de percolación obtenidos en la fase de simulación. Los resultados obtenidos en la simulación son validados a nivel de planta piloto teniendo en cuenta la influencia del porcentaje de carga en el procesado de la resina. Finalmente, se establece una comparativa entre los resultados obtenidos con las distintas cargas de CNT y CB. </span>
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-<span style="text-align: center; font-size: 75%;">Los resultados de la simulación nos demuestran que el valor del umbral de percolación es mucho menor en el caso de la utilización de CNT (alrededor del 3% en el caso de CNT frente a un 35% en el caso de CB). Los resultados experimentales nos muestras la fuerte dependencia de las propiedades eléctricas con el proceso de producción obteniendo variaciones de hasta dos órdenes de magnitud en los resultados experimentales empleando el mismo porcentaje de CNT pero distinto tipo de resina de poliéster.</span>
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-|  style="border-top: 1pt solid black;vertical-align: top;"|<span style="text-align: center; font-size: 75%;">Palabras clave:</span>
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-<span style="text-align: center; font-size: 75%;">Nanotubos de carbono Negro de carbono </span>
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-<span style="text-align: center; font-size: 75%;">Grafito</span>
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-<span style="text-align: center; font-size: 75%;">Resistividad eléctrica</span>
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-<span style="text-align: center; font-size: 75%;">Resina de poliéster</span>
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-|  style="border-top: 1pt solid black;vertical-align: top;"|
-|-
-|  colspan='2'  style="vertical-align: top;"|<big>Electrical properties in polyester resins: comparison of the use of carbon nanotubes (CNT) and carbon black (CB)</big>
-|-
-|  style="border-bottom: 1pt solid black;vertical-align: top;"|<span style="text-align: center; font-size: 75%;"> [[Image:Crespo_et_al_2018b-image2.png|54px]] </span>
-|  style="vertical-align: top;"|
-|-
-|  style="border-top: 1pt solid black;border-bottom: 1pt solid black;vertical-align: top;"|<span style="text-align: center; font-size: 75%;">Keywords:</span>
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-<span style="text-align: center; font-size: 75%;">Carbon nanotubes</span>
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-<span style="text-align: center; font-size: 75%;">Carbon black</span>
-−
-<span style="text-align: center; font-size: 75%;">Graphite</span>
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-<span style="text-align: center; font-size: 75%;">Electrical resistivity</span>
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-<span style="text-align: center; font-size: 75%;">Polyester resin</span>
-|  rowspan='2' style="vertical-align: top;"|<span style="text-align: center; font-size: 75%;">This work presents a comparison in the production of electrical conductivity polyester resins by doping it with two types of carbonous fillers; carbon nanotubes (CNT) and carbon black (CB). These polyester resins are used to obtain electrical conductivity powder gel coat. This type of coating reduces cycle times in the manufacture of composites due to the fact that significantly decrease curing time of the gel coat and eliminate secondary operations for the application of the final coating</span><span style="text-align: center; font-size: 75%;"> in the composite.</span>
-−
-<span style="text-align: center; font-size: 75%;">Electrical conductivity with different fillers content and percolation thresholds obtained in the simulation phase are detailed. The results obtained in the simulation are validated at the pilot plant level taking into account the influence of the loading percentage on the resin processing. Finally, a comparison between the results obtained with the different percentage of CNT and CB is made.</span>
-−
-<span style="text-align: center; font-size: 75%;">The results of the simulation show that the value of the percolation threshold is much lower in the case of CNT (about 3% in the case of CNT versus 35% in the case of CB). The experimental results indicate the strong dependence of the electrical properties on the production process obtaining variations of up to two orders of magnitude in the experimental results using the same percentage of CNT but different type of polyester resin.</span>
-|-
-|  style="border-top: 1pt solid black;vertical-align: top;"|
-|}
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-−
-<span id='_GoBack'></span>
 ==1 Introducction==
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 Particle size and aspect ratio are very important factors to achieve percolation at low percentages. Percolation threshold increases as the aspect ratio increases [1],[2]. The percolation limit is dependent upon the shape of the conductive particles. For traditional roughly spherical-shaped fillers at a random distribution, as carbon black, ~10–20% has to be added before the composite will be electrically conductive. The higher the aspect ratio (length-to-width ratio) of the particles, the lower is the concentration for percolation needed to take place. Carbon nanotubes (CNT) with a diameter of a few nanometres and a length of micrometres (i.e., a high aspect ratio) can form a conductive network at much lower volume fraction than cheaper, traditional fillers such as carbon black.
-<div class="center" style="width: auto; margin-left: auto; margin-right: auto;">
+<div class="center" style="width: auto; margin-left: auto; margin-right: auto;">[[File:Captura de pantalla 2022-10-12 130843.png|centre|600x600px]]<span style="text-align: center; font-size: 75%;">'''Figure 1. '''Aspect ratio influence on percolation threshold.</span></div>
- [[Image:Crespo_et_al_2018b-image5.png|600px]] <span style="text-align: center; font-size: 75%;">'''Figure 1. '''Aspect ratio influence on percolation threshold.</span></div>
 In this work, particles with different morphology were selected in order to study their influence on the electrical conductivity: spherical carbon black (CB) and tubular carbon nanotubes (CNT). In a first step, simulations were completed with unsatured polyester resin and carbonous particles (CNT and CB). Samples were obtained at pilot plant level and validation of simulation results was accomplished.

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