Membranas de intercambio protónico a partir de polímeros derivados de furfural.
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Date
2025
Journal Title
Journal ISSN
Volume Title
Publisher
Universidad de Concepción
Abstract
Ante la necesidad de satisfacer la creciente demanda energética, las celdas de combustible de membrana de intercambio protónico (PEMFC) se presentan como una alternativa interesante para la generación eficiente y limpia de energía en un amplio abanico de aplicaciones. Un componente esencial para el correcto funcionamiento de este tipo de equipos son las membranas de intercambio protónico (PEM), ya que permiten la migración de los protones requeridos para la transformación energética que tiene lugar en el sistema electroquímico de la celda.
Actualmente, las PEMFC emplean membranas basadas en politetrafluoroetileno sulfonado, como las fabricadas por Nafion™ o sus múltiples variantes. Sin embargo, estas membranas están asociadas a altos costos de fabricación y contaminación ambiental, lo que ha impulsado intentos de sustituirlas por alternativas renovables y menos costosas.
El furfural, una molécula obtenida de la biomasa lignocelulósica, se considera un material prometedor para la síntesis de nuevos polímeros biobasados que podrían reemplazar a las PEM actuales.
Este trabajo busca ahondar en la aplicación del furfural en este campo, razón por la que tiene como principal objetivo el desarrollo y caracterización de membranas de intercambio protónico elaboradas a partir de polímeros derivados de furfural. Esto se hizo por medio de la síntesis de PEM a partir de alcohol polivinílico (PVA), ácido sulfosuccínico (SSA) y furfural en composiciones variadas. La absorción de agua y la conductividad protónica de dichas membranas fueron medidas para determinar la contribución de cada componente sobre estas propiedades clave. Además, se analizaron las propiedades estructurales de las membranas mediante espectros FTIR e imágenes FESEM, mientras que su comportamiento térmico se estudió a través de análisis termogravimétrico.
Los resultados de este trabajo mostraron que las membranas de PVA/SSA/Furfural reticuladas presentaron absorciones de agua en un rango entre el 78 % y el 6 %, y conductividades protónicas que iban desde 0,72 mS/cm hasta los 3,08 mS/cm. Se observó que el furfural redujo significativamente la absorción de agua, aunque perjudicó ligeramente la conductividad protónica. Por su parte, un mayor contenido de SSA y altos porcentajes de absorción de agua mejoraron la conductividad protónica, pero se vio que un entrecruzamiento excesivo provocó una alta rigidez y rupturas en algunas membranas durante la humectación. Por su parte, el análisis FTIR confirmó la estructura propuesta para el polímero, las imágenes FESEM mostraron uniformidad superficial, y el análisis TGA situó las membranas de PVA/SSA/Furfural en un rango operacional de hasta aproximadamente 174 °C.
Faced with the ever-growing demand for energy supply, proton-exchange membrane fuel cells (PEMFC) present themselves as an interesting alternative for efficient and clean energy generation in a wide range of fields. An essential component required for the proper functioning of this kind of equipment are the proton exchange membranes (PEM) as they allow the migration of the protons required for the energetic transformation that takes place in the cell’s electrochemical system. PEMFC technology currently employs membranes based on sulfonated polytetrafluoroethylene like those made by Nafion™ or its many offshoots. However, these kinds of membranes are linked to high production costs and environmental pollution, both issues that have kickstarted attempts to replace them with cheaper and more renewable alternatives. Furfural, a molecule obtained from lignocellulosic biomass, is seen as a promising material for the synthesis of new biobased polymers that could replace the PEMs that are currently in use. This work seeks to gain further insight into the application of furfural in this field by having as its main objective the development and characterization of proton exchange membranes made from polymers derived from furfural. This was achieved through the synthesis of proton exchange membranes made from polyvinyl alcohol (PVA), sulfosuccinic acid (SSA) and furfural in varied compositions. The water absorption and proton conductivity of said membranes were measured to determine the contributing factor of each component in these key properties. The structural properties of the membranes were also analyzed through FTIR spectra and FESEM images. Meanwhile, their thermic behavior was studied through thermogravimetric analysis. The results of this work showed that thermally crosslinked PVA/SSA/Furfural membranes presented water absorptions between ranges of 78 % and 6 % and proton conductivities that went from 0,72 mS/cm to 3,08 mS/cm. Furfural was noted to significantly reduced water absorption in the membranes to the point of negatively impacting the proton conductivity to a lesser degree. Higher SSA content and high-water absorption percentages improved conductivity, but excessive crosslinking caused high rigidity and the rupture of membranes during humectation. Meanwhile FTIR analysis confirmed the proposed polymer structure and FESEM images showed surface uniformity. Finally, TGA analysis puts PVA/SSA/Furfural membranes in an operational range that goes up to around 174 °C.
Faced with the ever-growing demand for energy supply, proton-exchange membrane fuel cells (PEMFC) present themselves as an interesting alternative for efficient and clean energy generation in a wide range of fields. An essential component required for the proper functioning of this kind of equipment are the proton exchange membranes (PEM) as they allow the migration of the protons required for the energetic transformation that takes place in the cell’s electrochemical system. PEMFC technology currently employs membranes based on sulfonated polytetrafluoroethylene like those made by Nafion™ or its many offshoots. However, these kinds of membranes are linked to high production costs and environmental pollution, both issues that have kickstarted attempts to replace them with cheaper and more renewable alternatives. Furfural, a molecule obtained from lignocellulosic biomass, is seen as a promising material for the synthesis of new biobased polymers that could replace the PEMs that are currently in use. This work seeks to gain further insight into the application of furfural in this field by having as its main objective the development and characterization of proton exchange membranes made from polymers derived from furfural. This was achieved through the synthesis of proton exchange membranes made from polyvinyl alcohol (PVA), sulfosuccinic acid (SSA) and furfural in varied compositions. The water absorption and proton conductivity of said membranes were measured to determine the contributing factor of each component in these key properties. The structural properties of the membranes were also analyzed through FTIR spectra and FESEM images. Meanwhile, their thermic behavior was studied through thermogravimetric analysis. The results of this work showed that thermally crosslinked PVA/SSA/Furfural membranes presented water absorptions between ranges of 78 % and 6 % and proton conductivities that went from 0,72 mS/cm to 3,08 mS/cm. Furfural was noted to significantly reduced water absorption in the membranes to the point of negatively impacting the proton conductivity to a lesser degree. Higher SSA content and high-water absorption percentages improved conductivity, but excessive crosslinking caused high rigidity and the rupture of membranes during humectation. Meanwhile FTIR analysis confirmed the proposed polymer structure and FESEM images showed surface uniformity. Finally, TGA analysis puts PVA/SSA/Furfural membranes in an operational range that goes up to around 174 °C.
Description
Tesis presentada para optar al título de Ingeniero/a Civil Químico/a.
Keywords
Furaldehido, Polímeros, Membranas (Tecnología)