Facile synthesis of acyloxy-containing fluorene-based Cardo polyimides with high optical transparency, fluorescence and low dielectric constant

Simultaneously Improving the Optical, Dielectric, and Solubility Properties of Fluorene-Based Polyimide with Silyl Ether Side Groups

“…The absorption bands at around 1775 cm –1 (asymmetrical CO), 1720 cm –1 (symmetrical CO) and 1365 cm –1 (C–N), as well as the absence of hydroxyl absorption peak indicate the successful introduction of TBDPS groups and not the destruction of PI backbone during the silicon etherification. In addition, the absorption band of the symmetrical CO in the precursor PIs move to a higher wavenumber in the resulted PIs, which further signifies the introduction of TBDPS groups (Figure S3 in the Supporting Information) …”

“…In addition, the absorption band of the symmetrical C=O in the precursor PIs move to a higher wavenumber in the resulted PIs, which further signifies the introduction of TBDPS groups ( Figure S3 in the Supporting Information). 31 …”

“… d The data of thermal properties of the precursor OH–PI films come from our previous literatures. 31 , 37 …”

New polyimides containing methyl benzamidobenzoate or dimethyl benzamidoisophthalate as bulky pendant groups. Effects on solubility, thermal and gas transport properties

“…10 Many efforts have been made to improve the solubility of PIs, focusing on modifying the structural characteristics of the monomers to reduce the interactions between the polymer chains. Some feasible approaches such as the incorporation of bulky groups in the main or side chain, [11][12][13][14] flexible linkages, [15][16][17][18] alicyclic units, [19][20][21] fluorine groups, 3,22,23 alkyl/aryl silane fragments (-ArSi [R 1 R 2 ]Ar-), [24][25][26][27][28] among others, [29][30][31][32] have been used to prepare soluble PIs.…”

Novel cardo‐type heat‐resistant polyimides bearing 9H‐xanthene and polymer‐based nanocomposite consisting of NH2‐terminated TiO2: Synthetic strategies, extraction of methylene blue dye, and biological activities

“…22,23 Abundant efforts have been made to improve processing virtues of PIs, especially, by enhancing their fusibility and solubility, while keeping thermal constancy. Incorporation of ring-shaped structures, 24 nonplanar structures, 25 bulky side groups, 26,27 flexibilitie s linkages, 28 cardo groups, 29,30 and heterocyclic ring [31][32][33] are among modification methods used for improving properties of PIs.…”