Dielectric and gas transport properties of the films of thermally stable poly(arylene ether ketone)s containing content‐tunable benzimidazole moiety

Abstract

A series of thermally stable poly(arylene ether ketone)s (PAEKs) bearing benzimidazole structure in the main chains, named poly(arylene ether ketone-benzimidazole)s (PAEK-BIs), were directly synthesized by polycondensation of dimethyl bisphenol, dibenzimidazole bisphenol, and difluorobenzophenones. By systematically varying the amount ratio of two kind of bisphenols, the content of benzimidazole moiety in the backbone was controlled straightforwardly. The prepared amorphous polymers were characterized in terms of Fourier transform infrared spectroscopy, proton nuclear magnetic resonance, thermal, dielectric, and gas transport properties. Evaluation of solubility reveals that PAEK-BIs with >60% content of benzimidazole units could be soluble in commonly used organic solvents. Also polymers containing content-tunable benzimidazole show high glass-transition temperatures (T g 's, 157-319 C) and excellent thermal stability (e.g., temperature of 5% weight loss, above 438 C in air). Dielectric constants of PAEK-BIs measured at 25 C are all less than 2.66 in the frequency range of 0.1-50 kHz. For dense films, the ideal gas selectivity and permeability coefficients could be compared with that of commercial Ultem 1000 membrane, which indicate that the PAEK-BIs are potential to be used for gas separation membrane material.

Synthesis of high Tg and organosoluble poly(N-arylene benzimidazole ether imide) copolymers by C–N/C–O coupling reaction

“…The precipitation of PEIBI-90 and PIBI from sulpholane (as solvent) was observed; therefore, both polymers with low η inh values were acquired. Similar tendency was also reported by Liao et al 26…”

“…The better solubility of copolymer PEIBI(10–50) was attributed to ether linkages and pendent –CH 3 groups in a polymer backbone chain, which contributed to lower the rotational energy barrier of copolymers. 26 Hence, the greater the percentage of BPA in copolymers, the better would be the solubility. Homopolymer PIBI presented improved solubility compared to traditional (derived from 3,3′-diaminobenzidine) PBI, 27 PI and reported PBI–PI.…”

Partially bio‐based furyl‐functionalized organosoluble poly(ether ether ketone)s

“…The results of T g measurements are summarized in Table 2. The T g of BPF‐based poly(ether ether ketone) was 152 °C which is lower than the T g of BPA‐based poly(ether ether ketone) (157 °C) 61 . In the series of copoly(ether ether ketone)s, the T g value decreased with increase in BPF content.…”

Investigations of the humidity sensing properties of side-chain-type sulfonated poly (arylene ether ketone)s

“…14 PAEK is a type of material belonging to the engineering polymers with excellent properties and has been broadly applied in many fields. [15][16][17][18] Because of the outstanding characteristics of thermal stability, rigid nature, high mechanical strength, stability at high humidity, and filmforming ability, it has been widely investigated for fuel cells, 15 supercapacitors, 16 gas separation, 17 and water treatment. 18 In recent years, this type of material was found to have the ability to respond to RH variation.…”