Soluble Polyimides Based on 2,3,5-Tricarboxycyclopentyl Acetic Dianhydride

Abstract

ABSTRACT:Soluble polyimides with polyalicyclic structure were prepared by reactions of 2,3,5-tricarboxycyclopentyl acetic dianhydride (TCA-AH) with aromatic diamines. The two-step polymerization systems including poly(amic acids) synthesis and solution imidization using pyridine and acetic anhydride were performed and soluble polyimides with high inherent viscosities and high imidization ratios were obtained. TCA-AH polyimides exhibited high thermal stability in air and nitrogen, and good solubility in common polar solvents such as NMP (N-methyl-2-pyrrolidone). In comparison with soluble aromatic polyimides based on fluorine containing monomers, TCA-AH polyimides showed slightly less thermal stability and lower solubility in a few solvents.KEY WORDS Polyimide / Soluble Polyimide / Polyalicyclic Structure / 2,3,5-Tricarboxycyclopentyl Acetic Dianhydride / Solution Imidization / Thermal Stability / Solubility / Polyimides exhibit excellent thermal and mechanical properties, and have extensive engineering and microelectronics applications.

Promotion of Thermal Imidization of Semi-Aliphatic Polyimide Precursors by Incorporation of Polyethylene Glycol and Their Modified Solid Structures

“…The dianhydride moieties of HP-and CP-PIs are more flexible or asymmetric than that of CB-PI, which lowers their T g s. Among them, the T g of TC-PI was the lowest (280 °C). Although it was reported that thermal degradation of a fully imidized semialiphatic PI prepared from TCA and 4,4'-diaminodiphenyl ether (TCA/ODA) was not observed up to 400 °C [13], a weight loss was readily observed at around 240 °C for a TC-PI film cured at 230 °C. As described below, this weight loss is attributable to the imidization reaction of residual PAA component due to its low φ i .…”

“…imidization reaction, are complicated and not efficient due to their structural isomerism and large steric hindrance. Thereby, the φ i of such semialiphatic PIs are frequently difficult to increase at lower temperature [12,13].…”

Absorption, Fluorescence and Thermal Properties of Transparent Polyimides Based on 2,3,5-Tricarboxycyclopentylacetic Acid Dianhydride.

“…[1] In general, polyimides (PI) are prepared by a two-step process; first, diamines react with dianhydrides in aprotic polar solvents at room temperature to give poly(amide acid)s (PAA), the precursor of polyimides; second, poly (amide acid)s are converted to polyimides by either thermal or chemical imidization. Recently, new polyimides with various functional groups which show high solvent solubility, [2][3][4] high photosensitivity, [5][6][7] and photoconductivity, [8][9][10] have been actively investigated. Although polyimides have been widely used in microelectronics and space industry, their apparent color from yellow to brown has limited their application in optical communication and liquid crystal display devices.…”

“…Polyimides derived from 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropanedianhydride (6FDA), [12][13][14] are well known to be very transparent. I n recent years, polyimide prepared from alicyclic diamine [1 5-1 7] or alicyclic dianhydride [2,18] have been attracting much interest because of their good transparency, solubility, photochen ical and dielectric properties as well as good thermal stability. In our previous paper, [18] ultraviolet/visible absorption spectra and fluorescence spectra were investigated for transparent polyimides, PI(CBDA/DPM), PI(CBDA/ 6FdA), and PI (CBDAJDCHM) based on alicyclic dianhydride, 1 ,2 :3 ,4-cyclobutanetetracarboxylic dianhydride (CBDA), with an aromatic diamine, 4,4'-diaminodiphenylmethane (DPM), a fluorinated diamine, 2,2-bis(4-diaminodiphenyl)hexafluoropropane (6FdA), and an alicyclic diamine, 4,4'-diaminodicyclohexylmethane (DCHM).…”

“…Ltd. [ 19] for an alignment layer in liquid crystal displays (LCD), because of their good solubility in organic solvents, good processability, and high voltage holding ratios of liquid crystal cells with these polyimides as alignment films. Although polyimides derived from TCAAH with aromatic diamines have been investigated as to the solubility [2] and alignment properties in LCD, [19] their transparency, fluorescence, and thermal properties have not yet been investigated or reported. There have been n o reports on polyimides based on TCAAH with alicyclic diamines.…”