Part 1. Qualitative comparison between polymer and monomer model compound sulfonation

Abstract

The sulfonation kinetics of fluorine ended poly(ether ether ketone) (PEEK) in solution in 95.9% and 96.8% concentrated sulfuric acid was studied with the help of a model compound representative of the PEEK chain repeat unit. The reaction rate of the model compound sulfonation was found to be first order with respect to the aromatic ring to be sulfonated. Consequently, PEEK kinetic data were treated following a first order with respect to the unsulfonated repeat unit concentration. Two rate‐slowing effects were detected. They were attributed to ‘long range’ electronic effects resulting from the inductive nature of the fluorine atom, and from the electron‐withdrawing character of the grafted sulfonic acid group.© 2001 Society of Chemical Industry

Conductivity of composite membrane-based poly(ether-ether-ketone) sulfonated (SPEEK) nanofiber mats of varying thickness

“…5,6,[27][28][29][30][31][32][33] The main drawback of SPEEK has been found to be excessive swelling and dissolution in hot water, which prevents its practical use in DMFCs at intermediate temperatures 24,26 but not in the case of PEMFCs fed with hydrogen. Crosslinking SPEEK with other polymers enhances its mechanical stability under high temperature conditions.…”

On the polynaphthalimide synthesis—influence of reaction conditions

“…This spectroscopic method has already been used with success for similar studies [9,10]. One major advantage of this method is the possibility to directly investigate the reaction mixture without any treatment.…”

NMR evidence of the diamagnetic interaction between carbon nanotubes functionalized with polymer chains

“…For the SPEEK, the 13 C chemical shifts measured using high power 1 H decoupled experiments are in agreement with the literature on the topic of modified PEEK. 12 For the multiwalled CNTs ͓Fig. 4͑b͔͒, the observed 13 C NMR resonance at 119.6 ppm is typical for the sp 2 carbons from the sidewalls of the CNTs.…”

“…Figure 2 presents the data for multiwalled CNT, in good agreement with the literature. 12 For a delay of 30 s, 90% of the 13 C NMR signal is relaxed. From a biexponential fit, two spin-lattice relaxation times were found at 2.1 and 30.5 s. According to these relaxation properties, the high-resolution NMR study was confidently performed using a repetition time of 30 s which ensures that important information can be directly extracted from 13 C NMR lineshape.…”