A new soluble boron-containing poly(ether ether ketone) (B-PEEK) was synthesized through iridium-catalyzed C–H borylation of soluble meta-poly(ether ether ketone) and grafted on the surface of aluminum borate whiskers as the coupling agent between the whiskers and poly(ether ether ketone) (PEEK) matrix. The grafted aluminum borate whisker (g-W) reinforced PEEK composites were then prepared via a melt blending method. The coupling effect of B-PEEK was investigated by the interface micromorphology analysis and performance evaluation of PEEK composites. After grafting treatment with B-PEEK, aluminum borate whiskers were found to be dispersed evenly in the PEEK matrix without apparent aggregation. Ascribed to the strong interaction between whisker grafted chains and the PEEK matrix, g-W/PEEK composites show better mechanical properties and izod impact strength, higher crystallization temperature and crystalline fraction (χc) than those composites without grafting modification, indicating B-PEEK is an effective coupling reagent for PEEK and aluminum borate whiskers.

•Azobenzene-containing polyethersulfone with various spacer lengths was synthesized.•All polymers show good thermal stability.•The influence of spacer length on photoresponsive behavior was investigated.•The photoisomerization was more difficult to be induced for azobenzene-containing poly (ether sulfone)s with shorter spacers.•All polymers possessed remnant values of birefringence larger than 84% of the saturation values of birefringence.A series of azobenzene-containing side-chain poly(ether sulfone)s (azo-PES) with various spacer lengths (2, 6 or 12 methylene units) were successfully synthesized via a nucleophilic substitution grafting reaction between poly(ether sulfone)s with hydroxylphenyl side groups and azobenzene monomers. Their chemical structures and properties were characterized by means of IR, UV–vis and 1H NMR. These azo-polymers show good thermal stability with glass transition temperatures and 5% weight-loss temperatures above 119 °C and 347 °C, respectively. The results of photoisomerization experiments indicated that azo-PES polymer with longer spacers correspond to higher photoisomerization rates. Upon irradiation with a 532 nm neodymium doped yttrium aluminum garnet (Nd:YAG) laser beam, they presented remnant values of birefringence larger than 82% of the saturation value of birefringence, indicating the good stability of the photoinduced orientation. No fatigue phenomena have been observed after several cycles of inscription–erasure–inscription sequences.

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.