The Preparations and Water Vapor Barrier Properties of Polyimide Films Containing Amide Moieties

Abstract

Flexible displays are a systematic revolution in the field of display, in which high-performance and high-barrier polymer substrates are considered to be one of the most important key materials. In this work, high water vapor barrier polyimides containing amide moieties were synthesized via the ternary polymerization of 4,4 -diaminobenzailide (DABA), 4,4 -diaminodipheny ether (ODA), and 3,3 ,4,4 -biphenyl-tetracarboxylic acid dianhydride (BPDA) followed by thermal imidization. The relationship between the content of amide moieties and the water vapor barrier property of the prepared polyimides was studied by means of density test, water absorbing test, water contact angle test, water vapor permeation test, fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), thermogravimetry coupled with fourier transform infrared spectrometry (TG-FTIR), wide-angle X-ray diffraction analysis (WXRD), mechanical performance test, etc. The results show that the introduction of amide groups into polyimide (PI) main chains can improve the water vapor barrier properties of the polyimides effectively. The water vapor transmission rate (WVTR) of the polyimide films can be improved from 8.2365 g·(m 2 ·24 h) −1 to 0.8670 g·(m 2 ·24 h) −1 with the increasing content of amide moieties.

Reduced Coefficients of Linear Thermal Expansion of Colorless and Transparent Semi-Alicyclic Polyimide Films via Incorporation of Rigid-Rod Amide Moiety: Preparation and Properties

“…However, the rigidity of the common amide-containing monomers, such as 4,4'-diaminobenzanilide (DABA) is usually too high to afford the CPI resins good solubility in organic solvents. Thus, the amide-containing PI films can only be prepared by the soluble poly(amic acid) (PAA) precursors followed by high-temperature imidization procedure [30,31].…”

High-Barrier Polyimide Containing Carbazole Moiety: Synthesis, Gas Barrier Properties, and Molecular Simulations

“…Although the kinetic diameter of H 2 O was smaller, its diffusivity was lower than that of O 2 . This could be due to the strong interaction between polar H 2 O and PI matrix [ 51 ], which hindered the diffusion of H 2 O.…”

Preparation and Properties of Poly(imide-siloxane) Copolymer Composite Films with Micro-Al2O3 Particles

“…2018, 8, x FOR PEER REVIEW 5 of 11 symmetric deformation of the -CH3 group in -Si(CH3)2-, and the absorption band at 803 cm −1 was assigned to the Si-C vibration [11,41,[43][44][45]. The FT-IR spectrum of PAA-4 showed bands at 1721 cm −1 (carboxyl) and 1660 cm −1 (amide) owing to C=O stretching, and at 1545 cm −1 owing to C-N stretching (amide), suggesting the formation of PAA (Figure 1a) [11,34,46]. PI-4 exhibited absorption bands at 1785 cm −1 owing to imide C=O asymmetric stretching, 1726 cm −1 owing to imide C=O symmetric stretching, and 1375 cm −1 owing to imide C-N stretching (Figure 1b) [11,34,[46][47][48].…”

“…The FT-IR spectrum of PAA-4 showed bands at 1721 cm −1 (carboxyl) and 1660 cm −1 (amide) owing to C=O stretching, and at 1545 cm −1 owing to C-N stretching (amide), suggesting the formation of PAA ( Figure 1a) [11,34,46]. PI-4 exhibited absorption bands at 1785 cm −1 owing to imide C=O asymmetric stretching, 1726 cm −1 owing to imide C=O symmetric stretching, and 1375 cm −1 owing to imide C-N stretching (Figure 1b) [11,34,[46][47][48]. FT-IR spectra of the other PAAs and PIs are shown in Figures S2-S7.…”