Promising Fluorine-Free Ion Exchange Membranes Based on a Poly(ether-block-amide) Copolymer and Sulfonated Montmorillonite: Influence of Different Copolymer Segment Ratios

Manhal H Ibrahim Al-Mashhadani; Khirdakhanim Salmanzade; András Tompos; Asmaa Selim

doi:10.3390/membranes14010017

Promising Fluorine-Free Ion Exchange Membranes Based on a Poly(ether-block-amide) Copolymer and Sulfonated Montmorillonite: Influence of Different Copolymer Segment Ratios

Membranes (Basel). 2024 Jan 6;14(1):17. doi: 10.3390/membranes14010017.

Authors

Manhal H Ibrahim Al-Mashhadani^{1

2

3}, Khirdakhanim Salmanzade¹, András Tompos¹, Asmaa Selim^{1

4}

Affiliations

¹ Institute of Materials and Environmental Chemistry, HUN-REN Research Centre for Natural Sciences, Magyar Tudósok Körútja 2, H-1117 Budapest, Hungary.
² Hevesy György Doctoral School of Chemistry, Eötvös Loránd University, Pázmány Péter sétány 1/A, H-1117 Budapest, Hungary.
³ Institute of Laser for Postgraduate Studies, University of Baghdad, 10070 Baghdad, Iraq.
⁴ Chemical Engineering and Pilot Plat Department, Engineering and Renewable Energy Research Institute, National Research Centre, 33 El Bohouth Street, Giza 12622, Egypt.

Abstract

Novel composite membranes employing a poly(ether-block-amide) (PEBAX) copolymer and sulfonated montmorillonite (S-MMT) as a filler were developed. The ratio of polyether to polyamide blocks was investigated using PEBAX 2533 and PEBAX 4533 based on the membrane properties and performance. Additionally, the effect of the changing filler ratio was monitored. The interaction between the S-MMT as nanofiller and the polymer matrix of PEBAX2533 and PEBAX4533 as well as the crystalline nature and thermal and mechanical stability of the composite membranes were evaluated using Fourier Transform Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and tensile test. The composite membrane with 7 wt.% S-MMT showed the highest water uptake of 21% and 16% and an acceptable swelling degree of 16% and 9% for PEBAX 2533 and PEBAX 4533 composite membranes, respectively. In terms of water uptake and ion exchange capacity at room temperature, the new un-protonated membranes are superior to un-protonated Nafion. Meanwhile, with the same S-MMT content, the ion conductivity of PEBAX 2533 and PEBAX 4533 composite membranes is 2 and 1.6 mS/cm, and their ion exchange capacity is 0.9 and 1.10 meq/g.

Keywords: PEBAX; cation exchange membrane; copolymer; fluorine-free; fuel cell; inorganic–organic hybrid; ion conductivity; sulfonated montmorillonite.

Grants and funding

This research was funded by Project no. RRF-2.3.1-21-2022-00009, titled National Laboratory for Renewable Energy, which has been implemented with the support provided by the Recovery and Resilience Facility of the European Union within the framework of Programme Széchenyi Plan Plus.