Pyrene-functionalized PAEKs prepared from C–H borylation and Suzuki coupling reactions for the dispersion of single-walled carbon nanotubes

Abstract

The distribution of pyrene-functionalized single-walled carbon nanotubes (f-SWCNTs) within PEEK was investigated. Poly(aryl ether ketone)s with various contents of pyrene (PAEK-Py) were synthesized through iridium-catalyzed C–H borylation followed by Suzuki coupling. PAEK-Pys were characterized using UV–Vis, 1H NMR and gel permeation chromatography. The polymers were then used for non-covalent functionalization of pristine single-walled carbon nanotubes (SWCNTs). The functionalization efficiency was assessed by measuring the SWCNT dispersibility in chloroform. The maximal dispersion effect of the SWCNTs was obtained with the optimized conditions. In the presence of PAEK-Py-10, the dispersibility was as high as 272 mg L−1, and the dispersions containing 1.25 mg mL−1 of PAEK-Py-10 were very stable for 24 h with no solid deposits observed after being centrifuged at 5000 rpm for 15 min. Finally, pristine single-walled carbon nanotubes (SWCNTs) and non-covalently functionalized single-walled carbon nanotubes (f-SWCNTs) were used to prepare poly(ether ether ketone) (PEEK) composites (SWCNT/PEEK and f-SWCNT/PEEK) via co-blending in solution. The SWCNTs in the f-SWCNT/PEEK composite were dispersed better than those in the SWCNT/PEEK composite. These results suggest that PAEK-Pys could be used as an excellent dispersant for subsequent preparation of PEEK/SWCNT composites.