Novel aromatic polyamides and polyimides functionalized with 4-tert-butyltriphenylamine groups

New fluorinated aromatic polyamides based on N,N-bis(4-carboxyphenyl)-4-trifluoromethylaniline

A new aromatic diacid monomer, N, N-bis(4-carboxyphenyl)-4-trifluoromethylaniline, was synthesized by the substitution reaction of 4-trifluoromethylaniline with 4-fluorobenzonitrile, followed by alkaline hydrolysis of the dinitrile intermediate. Several polyamides with 4-trifluoromethyltriphenylamine moieties were prepared from the diacid and various aromatic diamines via the direct phosphorylation polycondensation. All the polyamides were amorphous and readily soluble in many polar organic solvents such as N, N-dimethylacetamide and N-methyl-2-pyrrolidone, and could be solution-cast into transparent, tough, and flexible films with good mechanical properties. They exhibited good thermal stability with glass transition temperatures of 260–330°C, 10% weight-loss temperatures above 500°C, and char yields higher than 60% at 800°C in nitrogen. These polymers had low dielectric constants of 3.35–3.72 (100 Hz), low water uptake of 1.80–2.60%, and high transparency with an ultraviolet–visible absorption cutoff wavelength in the range of 378–390 nm. Cyclic voltammograms of the polyamide films cast onto an indium-tin oxide–coated glass substrate exhibited a reversible oxidation redox coupled with oxidation half-wave potentials ( E 1/2) of 0.95–1.04 V versus silver/silver chloride in an acetonitrile solution.

Preparation and properties of highly organosoluble polyimides derived from 2,2′-disubstituted-4,4′-oxydianilines

Four novel aromatic, symmetrical ether diamines (2,2′-bis(biphenyl)-4,4′-oxydianiline, 2,2′-bis[4′-(3″,4″,5″-trifluorophenyl)phenyl]-4,4′-oxydianiline, 2,2′-bis[4-(naphthalene-1-yl)phenyl]-4,4′-oxydianiline, and 2,2′-bis[4″-(diphenylamino)phenyl]-4,4′-oxydianiline), were successfully synthesized through four steps using p-chloronitrobenzene as a starting material. Highly organosoluble polyimides were obtained by the reaction of these diamines with 2′2 ′-bis[4′-(3″,4″,5″-trifluorophenyl)phenyl]-4,4′,5,5′-biphenyltetracarboxylic dianhydride via a conventional two-step chemical imidization method. All the polyimides were thoroughly characterized by Fourier transform infrared, ultraviolet, fluorescence, gel permeation chromatography, and thermogravimetric analysis. The effect of the fluorine atoms directly linked to the lateral phenyl rings showed excellent dissolution and strong fluorescence. The polyimides exhibited excellent thermal stability, with decomposition temperatures (at 10% weight loss) above 530°C and glass transition temperatures in the range of 258–320°C. These outstanding combined features ensured that these polyimides could be used as memory materials for advanced microelectronic applications.

Recent advances in triphenylamine-based electrochromic derivatives and polymers

Triphenylamine-containing electrochromic materials with great potential applications in low energy-consumption displays, light-adapting mirrors in vehicles, and smart windows have experienced an exponential growth of research interests. In this review, the newly developed triphenylamine-based derivatives and polymers are reviewed and elaborated.

4-quinolin-8-yloxy Linked Triphenylamine Based Polyimides: Blue Light Emissive and Potential Hole-Transport Materials

A series of fluorescent donor- acceptor (D-A) alternating copolyimides (P1, P2, P3 and P4) with 4-quinolin-8-yloxy linked triphenylamine main polymer chain have been synthesized by conventional polycondensation. All the synthesized co-polyimides were characterized by elemental, gel permeation chromatography and FTIR spectral analysis. These newly prepared PIs possess HOMO energy levels in range of - 4.74 to - 4.78 eV and have medium optical band gaps. The photoluminescence spectral analysis revealed blue to violet emission with appreciable efficiency with lower onset oxidation potentials suitable for the facile hole injection materials. All the photophysical and electrochemical properties were also explored in context of effect of the pendant 4- quinolin-8-yloxy, indicating suitable combination of donor (TPA) on one hand and imide and pendant as acceptor on both ends.Graphical Abstract.

Thermal transition behaviors, solubility, and mechanical properties of wholly aromatic para-, meta-poly(ether-amide)s: effect on numbers of para-aryl ether linkages

para- and meta-poly(ether-amide)s containing 2, 3, 4 or 5 para-aryl ether linkages show different solubility, thermal transition behavior and mechanical properties.

Phenylethynyl- and naphthylethynyl-terminated hyperbranched polyimides with low melt viscosity

In the past decades, 4-phenylethynyl phthalic anhydride has been the most commonly used endcapper for polyimide (PI). A series of different groups of terminated hyperbranched PIs (HBPIs) were synthesized from 1,3,5-tris(2-trifluoromethyl-4-aminophenoxy)benzene, bis[4-(3,4-dicarboxyphenoxy)phenyl]ether dianhydride, and 4-phenylethynylphthalic anhydride or 4-(1-naphthylethynyl)phthalic anhydride. The glass transition temperatures ( Tgs) of the polymers varied from 166°C to 193°C. The 5% weight loss temperatures of polymers were in the range of 548 to 571°C and those of the endcapped HBPIs increased to the range of 600 to 601°C after curing. The PIs exhibited rather low melt viscosity at processing temperature and the complex viscosity increased continuously with the temperature increase. Because there is a large temperature difference between the Tg and cross-linking exothermic temperature, HBPIs provided a wide processing window.

Synthesis and characterization of novel electrochromic poly(amide-imide)s with N,N′-di(4-methoxyphenyl)-N,N′-diphenyl-p-phenylenediamine units

Novel redox-stable and multi-colored electrochromic poly(amide-imide)s with N,N′-di(4-methoxyphenyl)-N,N′-diphenyl-p-phenylenediamine units were synthesized and characterized.

High organosolubility of novel asymmetric polyimides-containing benzimidazole rings

Two tetramethyl-substituted diphenylmethane diamines, α,α-bis(4-amino-3,5-dimethylphenyl) phenylmethane (BADP) and 3,3′,5,5′-tetramethyl-4,4′-diaminodiphenylmethane (TMDA), were synthesized. Two series of novel soluble polyimides (PIs) with high glass transition temperature ( Tg) were derived from 3,3′4,4′-benzophenone tetracarboxylic dianhydride with 6,4′-diamino-2-phenylbenzimidazole and BADP (or TMDA) via one-pot synthesis using anhydrous N-methyl-2-pyrrolidone as a solvent. Precipitation or gelation does not occur during polymerization and imidization, and the resulting products dissolve well in polar aprotic solvents and phenolic solvents. The two series of PI films have good transparency in the visible light region, with a cutoff wavelength at 365 nm and higher than 50% of the transmittance at 450 nm. Tgs are in the range of 381–431°C, and 10% weight loss in nitrogen occurs above 530°C in all cases. Upon increasing BADP (or TMDA) moieties content, the Tg values decrease, whereas the thermal stability tends to increase. Moreover, the PIs-containing TMDA units have a higher thermal stability than those containing BADP units.