Preparation of highly H⁺ permeable sulfonated poly(ether ether ketone) cation exchange membranes and their applications in electro‐generation of thioglycolic acid

Abstract

BACKGROUND: Sulfonated poly(ether ether ketone) (SPEEK) was successfully synthesized from sulfonated 4,4′‐difluorobenzophenone, 4,4′‐difluorobenzophenone and bisphenol A. SPEEK cation exchange membranes were prepared by the casting method. The composition and morphology of SPEEK were characterized using Fourier transform infrared and 1H NMR spectroscopies, respectively. The ion exchange capacity (IEC), water uptake and degree of swelling of the membranes were also investigated. SPEEK120 was used as a separator in an electrolysis cell to produce thioglycolic acid (TGA).RESULTS: SPEEK polymerization was carried out at 145 and 175 °C for 10 h. The IEC of the SPEEK membranes was measured as 0.24–2.02 meq g−1 and the water uptake as 2.26–26.45%. The degree of swelling of the membranes was 1.71–15.28%. TGA was effectively prepared by electro‐reduction of dithioglycolic acid. The current efficiency peaked at 58.31% at room temperature with a current density of 15 mA cm−2.CONCLUSION: SPEEK120 membrane shows good dimensional stability and H+ permeability. Compared to the traditional metal‐reduction method, the current electro‐reduction technique avoids the use of zinc powder and so reduces environmental pollution. Copyright © 2009 Society of Chemical Industry

Functionalized poly(ether ether ketone) analogs via reactivity ratio controlled polycondensation

“…23 In turn the bromo methyl group provides access to a host of carbonyl containing functional groups. Other "pre" methodologies have led to PEEKs bearing tertiary amino, 24 amino (aniline) 25 and sulfonic acid groups, 9,26 while a post polymerization reduction of the carbonyl groups present in the benzophenone moiety results in the formation of secondary alcohols.…”

Tribological Behavior of Sulfonated Polyether Ether Ketone with Three Different Chemical Structures under Water Lubrication

“…Sulfonation modification is a common modification method for PEEK on account of its simplicity and effectiveness. The sulfonated PEEK (SPEEK) can be synthesized through sulfonation or polymerization [26][27][28]. The former utilizes sulfonation reagents (concentrated sulfuric acid and chlorosulfonic acid) for direct sulfonation, while the latter utilizes sulfonated monomers.…”

“…Wu et al synthesized a novel bisphenol-A (BPA)-type sulfonated PEEK and compounded it with 10 wt% carbon fiber, which exhibited a friction coefficient as low as 0.009 and a wear rate of grade 10 −8 when a 3 wt% NaCl solution was used as the lubricant at a low sliding speed (0.10 m/s) [30]. In comparison, the SPEEK's degree of sulfonation was controllable and repeatable using sulfonated monomer polymerization, and the sulfonic acid groups on the benzene rings had better chemical stability and strong hydrolysis resistance [27,28].…”