Design and preparation of poly(aryl ether ketone)/phosphotungstic acid hybrid films with low dielectric constant

Preparation of poly(ether ketone)s having phenyl, biphenyl, and terphenyl side groups and comparison of their properties

Three kinds of bis(aromatic fluoride) compounds, 3,5-bis(4-fluorobenzoyl)biphenyl (1), 3,5-bis(4-fluorobenzoyl)-1,1′:4′,1″-terphenyl (2), and 3,5-bis(4-fluorobenzoyl)-1,1′:4′,1″:4″,1′′′-quaterphenyl (3), were synthesized by cross-coupling of the corresponding triflates with phenylboronic acid. Linear poly(ether ketone)s (1x, 2x, and 3x) having phenyl, biphenyl, and terphenyl side groups, respectively, were prepared by the polycondensation of the bis(aromatic fluoride) compounds with bisphenol A (a) and 4,4′-dihydroxybiphenyl (b) in N-methyl-2-pyrrolidone. The obtained poly(ether ketone)s were characterized by X-ray diffraction, differential scanning calorimetry, and thermogravimetry. The structure–property relationships of these poly(ether ketone)s were examined and compared with those of poly(ether ketone)s (4x) having no side group, which were prepared from 3,5-bis(4-fluorobenzoyl)benzene (4). The properties of the poly(ether ketone)s, solubilities, and thermal properties were compared and discussed based on the length of the side groups.

The influence of different length of symmetrical alkyl side chains on the dielectric constant of soluble poly(aryl ether ketone) copolymers

A series of novel amorphous poly(aryl ether ketone) random copolymers containing rigid bulky pendant adamantyl groups and different length symmetrical alkyl side chains were synthesized and characterized. The chemical structures of the copolymers were confirmed by Fourier transform infrared and proton nuclear magnetic resonance spectroscopies. The influence of different length of symmetrical alkyl side chains on the dielectric constant, thermal property, mechanical property, and water uptake was investigated. The result shows that the dielectric constants ( κ) of the copolymer films ( κ = 2.72–2.90 at 1 MHz) are remarkably lower than commercial poly(ether ether ketone) ( κ = 3.27 at 1 MHz), and with the increasing length of symmetrical alkyl side chains of the copolymers, the dielectric constants of the copolymers decrease. The flexibility of the copolymer films exhibits a positive trend as the length of symmetrical alkyl side chains increases. Simultaneously, the copolymers maintain good solubility, low water uptakes, and excellent thermal and mechanical properties.

A new polymer with low dielectric constant based on trifluoromethyl-substituted arene: preparation and properties

A polymer based on trifluoromethyl-substituted arene was synthesized with high molecular weight (M_n) of 62 000 by the Scholl reaction. The polymer film showed low dielectric constants of about 2.56 in a range of frequencies from 1 to 25 MHz. Moreover, the polymer revealed high thermostability and good mechanical properties, suggesting that the polymer had potential applications in the electronics industry.