Low—Permittivity Copolymerized Polyimides with Fluorene Rigid Conjugated Structure

Abstract

As the miniaturization of electronic appliances and microprocessors progresses, low-permittivity interlayer materials are becoming increasingly important for their suppression of electronic crosstalk, signal propagation delay and loss, and so forth. Herein, a kind of copolyimide (CPI) film with a “fluorene” rigid conjugated structure was prepared successfully. By introducing 9,9-Bis(3-fluoro-4-aminophenyl) fluorene as the rigid conjugated structure monomer, a series of CPI films with different molecular weights were fabricated by in situ polymerization, which not only achieved the reduction of permittivity but also maintained excellent thermodynamic stability. Moreover, the hydrophobicity of the CPI film was also improved with the increasing conjugated structure fraction. The lowest permittivity reached 2.53 at 106 Hz, while the thermal decomposition temperature (Td5%) was up to 530 °C, and the tensile strength was ≥ 96 MPa. Thus, the CPI films are potential dielectric materials for microelectronic and insulation applications.

Dual‐Effect Coupling for Superior Dielectric and Thermal Conductivity of Polyimide Composite Films Featuring “Crystal‐Like Phase” Structure

“…The characteristic absorption peaks of the imide ring appeared at 1702−1715 cm −1 (stretching vibration of C═O) and 1364−1369 cm −1 (stretching vibration of C ─ N ─ C), respectively, indicating the successful preparation of PI (Figure S4, Supporting Information). [ 7 ] The transmission electron microscope (TEM) images show that the CaF 2 is composed of thin sheets with a particle size of ≈30 nm and exhibits a relatively smooth morphology (Figure 1e). And it can be seen from the inset that the CaF 2 powder appears grayish white.…”

“…[6] It is considered as a bottleneck polymer material to solve the constraints on the development of electronics and electrical industries. [7][8] However, most of the current researches only focus singularly on the dielectric properties or thermal conductivity of PI, for example, fluorinated ethylene propylene/PI, [9] boron nitride (BN)/PI, [10,11] and liquid crystal PI. [8] Although certain achievements have been achieved, the mechanism underlying the coordinated joint control of the thermal and dielectric properties of PI is rarely known.…”

Rigid/flexible molecular structure‐induced polyimide aerogels with ultralow permittivity and thermal insulation properties

“…Moreover, the characteristic peaks of the C–F groups are observed at 1230 cm −1 for BPDA‐6FAPB and CPA. Evidently, the peak width of C–F groups of CPA is enlarged and enhanced compared with the BPDA‐6FAPB aerogel [18]. As illustrated in Figure 1(c 1 –c 3 ), the three synthesised polyimide aerogels are slightly different in morphology, but they are all cylindrical structures with a diameter of 2.5 cm and a thickness of 2.5 mm.…”

Recent Progress in Cyclic Aryliodonium Chemistry: Syntheses and Applications

“…Fluorene is a common core structure of functional materials − and biologically active pharmaceuticals. ,,− Recently, the Wen group has presented a palladium-catalyzed approach for synthesis of substituted fluorenes 83 via sequence Mizoroki–Heck/reductive Heck domino reactions between cyclic diaryliodoniums 81 and terminal alkenes 82 in the presence of Et 3 N/HCOONa as base/reducing agents (Scheme ). Mechanistically, palladium species coordinate with cyclic diaryliodoniums 81 , and subsequent insertion into alkenes followed by β-H elimination process generates a key intermediate int11 .…”