Mastering Sulfonation of Aromatic Polysulfones: Crucial for Membranes for Fuel Cell Application

Abstract

The publication deals with the sulfonation of aromatic polysulfones that results in ionomers intended to be used as membranes for Proton Exchange Membrane Fuel Cells. The mechanical properties and the lifespan of the membranes depend, in particular, on the mode of synthesis of the ionomers and on chemical degradations which can occur and cut the polymeric chains. This article gives a progress report on the various methods giving access to polysulfone ionomers based on sulfonic acid functions. Among these methods, particular attention has been paid to electrophilic substitution from commercially available polysulfone. Although electrophilic sulfonation of aromatic molecules has been known for about one century, its application to the sulfonation of polymers still raises problems, e.g. homogeneity and degradations. A mechanism of chemical degradation is proposed to explain the chain breakings occurring in the course of reaction. The difficulty in passing from the laboratory scale to an industrial production is illustrated from reactions carried out at the pilot scale.

Electrochemical and structural characterization of sulfonated polysulfone

“…A wide range of characteriza tions was performed to determine the DS, indicating that NMR was the most accurate method. The Mn and PDI of the ionomers confi rmed that despite careful experimental conditions, CIS0 3 H produced signifi cant chain breakages, which were much more important than those induced by TMSCS, and consistent with the results reported by lojoiu et al [11 ]. Al though OS03H may appear more suitable for scaling up, we must emphasize that the expensive TMSCS can be easily generated in situ from a mixture of fairly cheap reagents (i.e., (CISi(CH 3 h) and CIS0 3 H).…”

“…The diphenylene sulfone endows the polymer backbone with insensi tivity to hydrogenation, thermal stability and oxidative resistance [10]. A comparative electrochemical study (i) of model molecules mimicking the backbone of high performance polymers and (ii) their sulfonated form confirmed that the polysulfone ionomers have a wider electrochemical stability window than that of polyether ether ketone and polyphenylene sulfide ionomers [11]. Therefore, sulfonated polysulfone (SPSU) ionomeric membranes have been extensively studied and tested for fuel cell applications [12,13].…”

Composite of Chitosan Vanilin / Sulfonated Polystyrene as Polymer Electrolyte Membranes : Cationic Exchange Capacity, Swelling Degree and Thermal Properties

“…Berbagai usaha telah dilakukan diantaranya pemakaian polimer alam (Mat and Liong, 2009;Ye et al, 2012), maupun sintetik (Smitha et al,2003;Iojoiu et al,2005. Polimer alam seperti kitosan dianggap cukup menjanjikan dalam aplikasi tersebut.…”

“…Reaksi pembentukan basa schiff dengan beberapa modifikator telah dipublikasikan sebelumnya (Santos et al, 2005;Wiyarsi, 2008;Jiao et al,2011;Pramono et al, 2012 et al, 2000;Smitha et al, 2003;Iojoiu et al,2005). Material tersebut memilki stabilitas termal yang tinggi dan juga sifat mekaniknya yang cukup baik pula (Martins et al,2003), namun demikian modifikasi pada bahan tersebut perlu dilakukan agar menghasilkan material yang bermuatan, sehingga dapat digunakan sebagai membran penukar proton yang dapat diaplikasikan sebagai membran elektrolit.…”

Investigation of Electrochemical and Morphological Properties of Mixed Matrix Polysulfone-Silica Anion Exchange Membrane

“…Activated carbon [5], carbon nano-tubes [6], sulfonated mesoporous silica [1], silica [7], and ironnickel oxide [8] are examples of inorganic materials that have been used as filler for the IEM matrix. The functions of inorganic fillers are to maintain water uptake, increase ion-exchange capacity and conductivity while retaining good mechanical and chemical stability [9]. However, the introduction of an inorganic filler into the polymer matrix should be carefully controlled to obtain a fine distribution of additives inside the membrane.…”