Determination of SPEEK sulfonation degree by titration

Authors

  • Marcela Carrera de Castro Faculty of Exact Sciences and Engineering, State University of Rio de Janeiro, Rio de Janeiro, Brazil
  • Jorge Trota Filho National Institute of Metrology, Quality and Technology, State University of Rio de Janeiro, Rio de Janeiro, Brazil

DOI:

https://doi.org/10.14295/bjs.v2i9.358

Keywords:

polymers, PEEK, SPEEK, titration, degree of sulfonation, ion exchange capacity, PEM

Abstract

Aromatic thermoplastics polymers such as poly (ether-ether ketone) PEEK, have shown to be very promising for the production of proton exchange membranes, due to their characteristics. Studies demonstrate that chemically modified polymers can have improved original properties. The sulfonation functionalization process is one of the strategies for modifying polymeric materials, which promote greater hydrophilicity, better ionic conductivity, greater wettability and better performance as a proton exchange membrane. PEEK was treated with sulfuric acid, obtaining SPEEK. The polymer was titrated in order to study its degree of sulfonation (SD), evaluate its relationship with the ion exchange capacity (IEC) and its potential application as PEM. In order to investigate the sulfonation degree (DS) of SPEEK and evaluate its relationship with the polymer's ionic exchange capacity (IEC), 0.3 g SPEEK samples were immersed in a sodium chloride solution to carry out the proton exchange. The titrations of saline solutions were performed with sodium hydroxide and, through the volume obtained, its IEC = 0.5435 meq.g-1 and its SD = 0.6 were obtained. It was proved that the relationship between the polymer mass, degree of sulfonation and ion exchange capacity can be modified, due to the optimization of the available amount of polymer and that, having knowledge of the SD of the polymer, it is possible to estimate the amount of base to be consumed, which is related to the amount of protons coming from SPEEK and present in the saline solution.

References

Barreto, E. G., Fiuza, R A., Catão, R. S., Pepe, Y., José, N. M., & Boaventura, J. S. (2007). Caracterização de membranas poliméricas obtidas a partir do S-PEEK para aplicação em células combustíveis do tipo PEM. 9o Congresso Brasileiro de Polímeros, Campina Grande, Paraíba. https://www.ipen.br/biblioteca/cd/cbpol/2007/PDF/642.pdf

Changkhamchom, S., & Sirivat, A. (2019). Sulfonated (graphene oxide/poly (ether ketone ether sulfone) (S-GO/S-PEKES) composite proton exchange membrane with high proton conductivity for direct methanol fuel cell. Polymer-Plastics Technology and Materials, 1900-1913. https://doi.org/10.1080/25740881.2019.1587770 DOI: https://doi.org/10.1080/25740881.2019.1587770

Chen, C.-C.; Dai, L., Ma, L., & Guo, R.-T. (2020). Enzymatic degradation of plant biomass and synthetic polymers. Nature Reviews Chemistry, 4, 114-126. https://doi.org/10.1038/s41570-020-0163-6 DOI: https://doi.org/10.1038/s41570-020-0163-6

Gao, S., Chen, X., Xu, H., Luo, T., Ouadah, A., Fang, Z., Li, Y., Wang, R., Jing, C., & Zhu, C (2018). Sulfonated graphene oxide-doped proton conductive membra-nes based on polymer blends of highly sulfonated poly(ether ether ketone) and sulfonated polybenzimidazole. Journal of Applied Polymer Science, 135(37). https://doi.org/10.1002/app.46547 DOI: https://doi.org/10.1002/app.46547

Habert, A. C., Borges, C. P., & Nobrega, R. (2013). Processos de Separação com Membranas. Rio de Janeiro: e-papers, 2006.

Heo Y., Im, H., & Kim, J. (2013). The effect of sulfonated graphene oxide on Sulfonated Poly (Ether Ether Ketone) membrane for direct methanol fuel cells. Journal of Membrane Science, 425-426, 11-22. http://dx.doi.org/10.1016/j.memsci.2012.09.019 DOI: https://doi.org/10.1016/j.memsci.2012.09.019

Hickner, M. A, Ghassemi, H., Kim, Y. S., Einsla, B. R., & Mcgrath J. E. (2004). Alternative polymer systems for proton exchange membranes (PEMs). Chemical Reviews, 104, 4587-4612. https://doi.org/10.1021/cr020711a DOI: https://doi.org/10.1021/cr020711a

Kumar, R. Mamlouk, M., & Scott, K. (2014). Sulfonated polyether ether ketone – sulfonated graphene oxide composite membranes for polymer electrolyte fuel cells. Royal Society of Chemistry Advances, 4, 617-623. https://doi.org/10.1039/C3RA42390E DOI: https://doi.org/10.1039/C3RA42390E

Mano, E. B. (2019). Polímeros como materiais de engenharia. 8ª reimpressão. São Paulo: Edgard Blücher.

Marrero, J. C., Gomes, A. S., Hui, W. S., Filho, J. C. D., & Oliveira, V. S. (2017). Sulfonation degreed effecton ion-conducting SPEEK-titanium oxide membranes properties. Polímeros, 27(3), 189-194. http://dx.doi.org/10.1590/0104-1428.07216 DOI: https://doi.org/10.1590/0104-1428.07216

Souto, K. M., Silva, A. A., Silva, A. A., Carvalho, L. H., Costa, A. C. F. M., & Lira, H. (2005). Classificação de membranas cerâmicas e poliméricas quanto à faixa de porosidade utilizando um sistema de separação óleo/água em escala de laboratório. Revista Matéria, 10(3), 437-446. http://www.materia.coppe.ufrj.br/sarra/artigos/artigo10680/

Trindade, L. G (2015). Membranas poliméricas para células a combustível: estudo de resinas trocadoras de íons combinadas a líquidos iônicos. Tese (Doutorado em Química). Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil.

Williams, M. C. Fuel Cell Handbook. U.S. (2004). 7th edition. Department of Energy, National Energy Technology Laboratory. Morgantown. https://www.netl.doe.gov/sites/default/files/netl-file/FCHandbook7.pdf

Yusoff, Y. N., Loh, K. S., Wong, W. Y., Daud, W. R. W., & Lee, T. K. (2020). Sulfonated graphene oxide as an inorganic filler in promoting the properties of a polybenzimidazole membrane as a high temperature proton exchange membrane. International Journal of Hydrogen Energy, 45(51), 27510-27526. https://doi.org/10.1016/j.ijhydene.2020.07.026 DOI: https://doi.org/10.1016/j.ijhydene.2020.07.026

Zaidi, S. M. J., & Lakhi, K. S. (2016). Sulfonated Aromatic Polymer. In: Drioli, E., Giorno, L. (eds). Encyclopedia of Membranes. Springer, Berlin, Heidelberg. 2016. https://doi.org/10.1007/978-3-662-44324-8_560 DOI: https://doi.org/10.1007/978-3-662-44324-8_560

Published

2023-09-01

How to Cite

Castro, M. C. de, & Trota Filho, J. (2023). Determination of SPEEK sulfonation degree by titration. Brazilian Journal of Science, 2(9), 13–21. https://doi.org/10.14295/bjs.v2i9.358