Synthesis and characterization of soluble poly(ether imide)s based on 2,2′-bis(4-aminophenoxy)-9,9′-spirobifluorene

Synthesis and Characterization of Novel Triphenylamine-Containing Electrochromic Polyimides with Benzimidazole Substituents

Two novel electrochromic aromatic polyimides (named as TPA-BIA-PI and TPA-BIB-PI, respectively) with pendent benzimidazole group were synthesized from 1,2-Diphenyl-N,N'-di-4-aminophenyl-5-amino-benzimidazole and 4-Amino-4'-aminophenyl-4″-1-phenyl-benzimidazolyl-phenyl-aniline with 4,4'-(hexafluoroisopropane) phthalic anhydride (6FDA) via two-step polymerization process, respectively. Then, polyimide films were prepared on ITO-conductive glass by electrostatic spraying, and their electrochromic properties were studied. The results showed that due to the π-π* transitions, the maximum UV-Vis absorption bands of TPA-BIA-PI and TPA-BIB-PI films were located at about 314 nm and 346 nm, respectively. A pair of reversible redox peaks of TPA-BIA-PI and TPA-BIB-PI films that were associated with noticeable color changed from original yellow to dark blue and green were observed in the cyclic voltammetry (CV) test. With increasing voltage, new absorption peaks of TPA-BIA-PI and TPA-BIB-PI films emerged at 755 nm and 762 nm, respectively. The switching/bleaching times of TPA-BIA-PI and TPA-BIB-PI films were 13 s/16 s and 13.9 s/9.5 s, respectively, showing that these polyimides can be used as novel electrochromic materials.

Redox-active polyimides for energy conversion and storage: from synthesis to application

As the demand for next-generation electronics is increasing, organic and polymer-based semiconductors are in the spotlight as suitable materials owing to their tailorable structures along with flexible properties. Especially, polyimide (PI) has been widely utilised in electronics because of its outstanding mechanical and thermal properties and chemical resistance originating from its crystallinity, conjugated structure and π-π interactions. PI has recently been receiving more attention in the energy storage and conversion fields due to its unique redox activity and charge transfer complex structure. In this review, we focus on the design of PI structures with improved electrochemical and photocatalytic activities for use as redox-active materials in photo- and electrocatalysts, batteries and supercapacitors. We anticipate that this review will offer insight into the utilisation of redox-active PI-based polymeric materials for the development of future electronics.

Synthesis and characterization of novel star-branched polyimides derived from 2,2-bis[4-(2,4-diaminophenoxy)phenyl]hexafluoropropane

A series of novel star-branched fluorinated polyimides was synthesized from anhydride-terminated linear poly(amide acid)s and aromatic fluorinated tetramine BDAPFP.

New organosoluble aromatic poly(esterimide)s containing pendent pentadecyl chains

A new diimide dicarboxylic acid, namely 2,2′-(4-pentadecyl-1,3-phenylene)bis(1,3-dioxoisoindoline-5-carboxylic acid), containing preformed imide rings and pentadecyl chain, was synthesized by the reaction of 4-pentadecylbenzene-1,3-diamine with trimellitic anhydride. A series of new aromatic poly(esterimide)s (PEIs) was synthesized using diphenylchlorophosphate-activated direct polycondensation of 2,2′-(4-pentadecyl-1,3-phenylene)bis(1,3-dioxoisoindoline-5-carboxylic acid), with five commercially available bisphenols, namely 4,4′-isopropylidenediphenol (I), 4,4′-(hexafluoroisopropylidene)diphenol (II), 4,4′-oxydiphenol (III), 4,4′-biphenol (IV), and 4,4′-(9-fluorenylidene)diphenol (V) in the presence of pyridine and lithium chloride. Inherent viscosities of PEIs were in the range 0.54–0.83 dL g−1 in chloroform (CHCl3) at 30 ± 0.1°C. PEIs containing pendent pentadecyl chains were soluble in organic solvents such as CHCl3, m-cresol, N, N-dimethylacetamide, 1-methyl-2-pyrrolidinone, pyridine, and nitrobenzene. Tough, transparent, and flexible films of PEIs could be cast from their CHCl3 solutions. PEIs exhibited glass transition temperature in the range 145–198°C. The temperature at 10% weight loss of PEIs, determined by thermogravimetric analysis under the nitrogen atmosphere, was in the range of 450–470°C indicating good thermal stability.

Synthesis and Characterization of New Optically Active Poly (ethyl L-lysinamide)s and Poly (ethyl L-lysinimide)s

Ethyl L-lysine dihydrochloride was reacted with three different dianhydrides to yield the poly (ethyl L-lysinimide)s (PI(1-3)); it was also reacted with two different diacyl chlorides to yield the poly (ethyl L-lysinamide)s (PA(4-5)). The resulting polymers have inherent viscosities in the range of 0.15 to 0.42 dL g(-1). These polymers are prepared from an inexpensive starting material and are optically active, potentially ion exchangeable, semicrystalline, thermally stable, and soluble in polar aprotic solvents such as DMF, DMSO, NMP, DMAc, and sulfuric acid. All of the above polymers were fully characterized by FT-IR and (1)H NMR spectroscopy, elemental analysis, WAX diffraction, TGA, inherent viscosity measurement, and specific rotation.

Novel Poly(amideimide)s: Synthesis, Thermal, and Optical Characterization

A series of new aromatic poly(amideimide)s is synthesized via one-step high- temperature polycondensation from prepared diamidedianhydrides and various diamines: 4,4'-(hexafluoro-isopropylidene)dianiline, 4,4'-(9-fluorenylidene)dianiline, 2,7-diaminofluorene and 2,4-diamino-6-phenyl-1,3,5-triazine. Molecular and structural characterization of the resulting polymers is carried out using Fourier transform infrared and nuclear magnetic resonance spectroscopies. The resulting polymers exhibit a good level of thermal stability. The temperature of 10% weight loss is in the range of 420—525 °C (in N2) associated with relatively high glass transition temperatures (249—299 °C). The polymers' residual weight loss at 800 °C is higher than 40%. The optical and photoluminescence characteristics of synthesized poly(amideimide)s were investigated in solution and in blend with poly(methylmethacrylate) (PMMA). The photoluminescence spectra of the polymers in N-methyl-2-pyrrolidinone solution exhibit maximum emission wavelength in the range of 405—495 nm depending upon the polymer structure.