Fluorescent, electroactive, thermally stable triphenylamine‐ and naphthalene‐based polyimides for optoelectronic applications

Abstract

To tune the photophysical properties of polyimides (PIs), a diamine containing naphthalene and triphenylamine units, N 1 -(4-aminophenyl)-N 1 -[(4-naphthalene-2-yloxy)phenyl]benzene-1,4-diamine (DA), was synthesized. A series of fluorescent electroactive new PIs from synthesized DA were prepared with conventional thermal imidization with dianhydride. The selected dianhydride were used to study and compare the effects of rigid planar phenyl, flexible phenoxy, and nonplanar flexible hexafluoroisopropyidene and carbonyl groups in the main polymer backbone on the optoelectronic properties and processability of materials. The structures of the synthesized diamine and its PIs were evaluated by spectral and CHNS elemental analysis. The optoelectronic and thermal properties of PIs revealed intense blue-light emission (428-477 nm), a low oxidation potential (0.3-1.3 V), and a lower highest occupied molecular orbital-lowest unoccupied molecular orbital gap (2.92-3.21 eV). The observed behavior and properties of our synthesized PIs suggest their potential as future hole-transport materials in optoelectronic applications. V C 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44526.

Investigation of thermal and fluorescent properties of benzoxazole-linked triphenylamine-based co-polyimides

“…The solubility of 1-PIs was checked by dissolving 10 mg of polyimide in highly polar solvents like THF, DMSO, DMF, DMAc, NMP, and m-cresol using 1 mL each. Neat polyimides derived from ODA are known to display very poor organic solubility due to regularity in polymer chain and symmetrical chain packing, 43 while our synthesized co-polyimides displayed appreciable solubility in different organic solvents. 1-PIs exhibited good organosolubility showing dependence on the chain packing ability and rigidity of the polymer chains.…”

“…The synthesized ODA-based co-polyimides in comparison to ODA-based polyimides have good organic solubility which make possible the molecular weight estimation of the synthesized polymers from inherent viscosity measurement. 43 The inherent viscosity was measured in NMP (0.3 g dL −1 ) at 30°C. The η inh of these polyimides was found to be in the range of 0.93–1.14 dL g −1 .…”

“…: 10 μM) as shown in Figure 5(a). The absorption spectra of neat ODA polyimides ranged from 245 nm to 270 nm, 43 while the absorption spectra of 1-PIs exhibited two absorption maxima from 263 nm to 270 nm and 365 nm to 370 nm. The maximum absorption toward the higher energy corresponds to π to π* transitions, whereas n –π* transitions give shoulder peak due to lone pair electron of TPA unit, toward lower energy region.…”

“…In our previous work on the electroactive polyimides, we have reported polyimides with TPA-based carbazole, naphthoxy, and 4-quinoline-8-yloxy pendant groups having potential optical and photophysical properties, suitable for electrochromic applications. 43,44 Herein, we report synthesis and characterization of a series of co-polyimide by reacting two diamines, one bearing electron-rich TPA unit with benzoxazole as pendant group and the other 4,4′-oxydianiline (ODA) widely known to impart good film-forming ability with commercially available dianhydrides. It has been reported that rigid structure of benzoxazole and intramolecular hydrogen bonding greatly enhances the regularity of polymer backbone leading to improved properties like high thermal decomposition temperature, glass transition temperature, and better optical properties with good solubility.…”

Poly(azomethine‐imide)s containing siloxane moities: Optical, thermal, mechanical, and morphological properties

“…As can be seen in Figure and Table , poly(azomethine‐imide)s were shown three reflectance bands in the range from 314 to 320 nm, 364 to 372 nm, and 459 to 462 nm. The first and second bands were attributed to π → π* and n → π* transitions of imide linkage, respectively, and the last band was attributed to n → π* transition of the azomethine (NCH) linkage …”