Synthesis and properties of ultralow dielectric porous polyimide films containing adamantane

Abstract

A series of novel ultralow dielectric porous polyimide (PI) films containing adamantane groups was prepared via the thermolysis of polyethylene glycol (PEG) oligomers mixed into PI matrix. Scanning electron microscopy results indicated that the porous PI films showed closed pores with an average diameter of 120 ± 10 nm. Good thermal properties with 5% weight loss temperature of 499 °C in air atmosphere and glass transition temperature in excess of 310 °C were shown for porous PI films. Notably, the ultralow dielectric constant of porous PI films with 1.85 at 1 MHz was obtained and revealed via broadband dielectric spectroscopy. The effects of the chemical structure of the PI matrix and PEG content on the decomposition behavior of PEG and the performance of porous films were investigated. Wide‐angle X‐ray diffraction results indicated that the PI matrix with large d‐spacing generated weaker interactions between the PEG and PI backbone than those of PI matrix with small d‐spacing. As a result, the PEG for the PI matrix with large d‐spacing was completely decomposed. As indicated by the broadband dielectric spectroscopy results, lower dielectric porous PI films were prepared when the PEG contents in the PI matrix increased from 0 to 20 wt %. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 549–559

High‐Tg porous polyimide films with low dielectric constant derived from spiro‐(adamantane‐2,9′(2′,7′‐diamino)‐fluorene)

“…According to the peaks at 2θ = 15.9°, the calculated d ‐spacing value of PI chains reached 0.55 nm. In our previous research, the calculated d ‐spacing of PI films prepared by 6FDA and BAAD/ODA reached 0.68 nm at a molar ratio of 5:5. Thus, the d ‐spacing value of as‐prepared PI film using SADAF was smaller than that of PI films containing BAAD as SADAF exhibits a larger steric hindrance and smaller free volume.…”

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Transparent and soluble polyimide films containing 4,4′‐isopropylidenedicyclohexanol (Cis‐HBPA) units: Preparation, characterization, thermal, mechanical, and dielectric properties

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“…Excellent performance of polyimides like highly mechanical and thermally stable, electrical, wide chemical resistance, and relatively low dielectric constants, and so forth makes themselves attractive candidates in microelectronic and aerospace engineering . Over the past years, numerous diamines or dianhydrides are designed aiming to obtain polyimides with ultralow dielectric constant, high glass transition temperature, good biocompatibility, low coefficient of linear expansion, ultrahigh tensile strength, optoelectronic and gas separation properties, and so forth, Nevertheless, most of these polyimides based on aromatic building blocks can easily lead to defects like insolubility and low transmittance and hence impede their molding processing and application in optoelectronic devices. Consequently, the development of colorless and soluble polyimides is entirely justified.…”

A compatible and crosslinked poly(2‐allyl‐6‐methylphenol‐co‐2,6‐dimethylphenol)/polystyrene blend for insulating adhesive film at high frequency

“…To prevent signal distortion arising from dielectric loss, it is urgent to develop a novel high‐frequency adhesive for copper‐clad laminates (CCLs) that will have high thermal stability and low D k (low k ) and D f . A number of polymers with low k have been developed, such as polyimides, poly(aryl ether)s, poly(ether ketone)s, heteroaromatic polymers, and fluoropolymers . Poly(phenylene ether) (PPE) is an engineering polymer that has been widely used in many advanced industrial fields, particularly in the microelectronic industry because of its low D k and D f properties, low moisture absorption, and excellent thermal properties and chemical resistance.…”