Aromatic Tetracarboxylic Dianhydrides Research Articles

Synthesis and properties of new transparent (co)polyimides based on adamantane-containing diamines and aromatic tetracarboxylic dianhydrides

Synthesis and properties of new transparent (co)polyimides based on adamantane-containing diamines and aromatic tetracarboxylic dianhydrides

Preparation and properties of polyimides having porphyrin moieties for heavy metals removal

A tetramine monomer containing porphyrin moiety is prepared in high purity by the propionic acid-mediated condensation of pyrrole with 4-cyanobenzaldehyde and then reduction in the tetracyano intermediate. The thermally stable porphyrin-based polyimides (PI)s are prepared using tetramine and four aromatic tetracarboxylic dianhydrides via a two-step method in quantitative yields with inherent viscosities of 0.34–0.63 dL/g. The PIs are soluble in some organic solvents such as N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide and dimethyl sulfoxide. The resultant PIs had high glass transition temperatures and displayed outstanding thermal stability up to 500 °C. The resulting polymers revealed strong UV–Vis absorption band around 422 nm in DMF. Wide-angle XRD measurements exhibited that the PIs were amorphous. The polymer films had tensile strengths 101–128 MPa, elongates at break of 7–11% and tensile moduli of 2.0–2.2 GPa. One of the PIs was applied to examine the adsorption properties of two heavy metal ions (Cd2+ and Hg2+) at pH 7. The results revealed that the applied PI was an outstanding sorbent for heavy metal ions. The goal of this study is the preparation of hydrophobic PIs for ion-selective membranes and chemical sensors to adsorb of toxic heavy metals.

Synthesis and properties of highly organosoluble aromatic polyimides containing N-(4-(di(1H-indole-3-yl)methyl)phenyl) moieties

A new diamine monomer containing indole unit, 3,5-diamino- N-(4-(di(1H-indol-3-yl)methyl)phenyl)benzamide, was successfully synthesized and applied in the preparation of a series of polyimides (PIs) via a conventional two-step polymerization procedure with three aromatic tetracarboxylic dianhydrides. The prepared polymers showed excellent solubility in organic solvents such as N-methyl-2-pyrrolidinone (NMP), N, N-dimethylacetamide, and N, N-dimethylformamide. Flexible and strong films of PIs were obtained via casting from their solutions. The glass transition temperature of these polymers was in the range of 223–264°C. They were fairly stable up to a temperature around 300°C and lost 10% weight at 372°C in nitrogen atmosphere. All of the polymers revealed absorption maxima around 323 nm with a fluorescence emission maxima around 378–406 nm in NMP. The cyclic voltammetry of the PIs exhibited an oxidation wave with a peak at 1.07 V. The resulting polymer films had tensile strengths from 83 MPa to 107 MPa, elongates at break of 7–10%, and tensile moduli of 2.2–2.3 GPa.

Fully Bio-based Aromatic Polyimide Using 4-Aminocinnamic Acid and Mellophanic Dianhydride as Bio-derived Monomers

Mellophanic dianhydride which is aromatic tetracarboxylic dianhydride monomer for synthesis of polyimide, were derived from maleic anhydride and 2,5-dimethylfuran as the bio-derived monomers with the new approach. The obtained mellophanic dianhydride is used to synthesize the fully bio-based poly(amic acid) using 4-aminocinnamic acid dimer as the bio-based aromatic diamine monomer. For controlling the solubility of polyimide, thermal or chemical imidizations are carried out by using stepwise heating method or acetic anhydride/pyridine treatment, respectively. Thermally imidized polyimides show low solubility for organic solvent, however, chemically-imidized polyimide show good solubility for N-methyl-2-pylloridione, dimethylsulfoxide, and N,N-dimethylformamide. In addition, all the obtained polymers show high heat resistance properties, 10 % decomposed temperature (T d10), of poly(amic acid) is 331 °C, while T d10 of polyimides are 389 °C regardless of imidization processes. Thus, fully bio-based polyimides having high thermostability is developed for the first time.

Heat-Resistant Network Block Copolymers Based on Rolivsans Modified with Tetracarboxylic Anhydrides and Aromatic Tetraamines

The efficiency of a new approach to structural-chemical modification of unsaturated thermosetting resins was demonstrated by the example of curing of rolivsans containing small additions (0.5–2.0 wt %) of aromatic tetracarboxylic dianhydrides and aromatic tetraamines. As shown by dynamic mechanical and thermal analysis, the heat resistance of the modified matrix of the cured rolivsan, which is mainly used as a heat-resistant polymer compound for electric insulation, increases from 280 to 340–375°С, and the rigidity parameters decrease by a factor of 3–6, which is of much practical interest.

High-temperature chemical transformations of tetracarboxylic acid dianhydrides with aromatic diamines in rolivsan matrix

Thermochemical transformations of ternary thermosetting systems consisting of rolivsans, aromatic tetracarboxylic acid dianhydrides, and aromatic diamines were studied by dynamic mechanical and thermal analysis. The influence of the composition and curing conditions of these systems on the thermomechanical properties of new glassy network block copolymers exhibiting enhanced heat resistance was determined.

Synthesis and properties of electroactive aromatic polyimides with methyl- or trifluoromethyl-protecting triphenylamine units

Two series of new redox-active aromatic polyimides with methyl- (–CH3) or trifluoromethyl (–CF3)-protecting triphenylamine moieties were prepared from 4,4′-diamino-4″-methyltriphenylamine and 4,4′-diamino-4″-(trifluoromethyl)triphenylamine with aromatic tetracarboxylic dianhydrides via the conventional two-step polycondensation technique. Flexible and strong polyimide films could be obtained via the thermal curing of their precursor poly(amic acid) films or direct solution cast from some organosoluble polyimides. The polyimides showed high glass-transition temperatures between 269°C and 312°C, and they did not show significant decomposition before 500°C in air or under nitrogen atmosphere. Cyclic voltammograms of the polyimide films on the indium–tin oxide-coated glass substrate exhibited a pair of reversible redox waves with half-wave oxidation potentials of 1.08–1.10 V (for the –CH3 series) and 1.23–1.26 V (vs. silver/silver chloride; for the –CF3 series) in acetonitrile solution. The polyimide films showed anodic electrochromism from pale yellow neutral state to purplish blue (for the –CH3 series) and chrome yellow (for the –CF3 series) when oxidized.

Synthesis and electrochemical properties of new redox-active polyimides with (1-piperidinyl)triphenylamine moieties

A series of new electroactive aromatic polyimides with (1-piperidinyl)triphenylamine moieties were prepared from 4,4′-diamino-4″-(1-piperidinyl)triphenylamine and aromatic tetracarboxylic dianhydrides via the conventional two-step polycondensation technique. Flexible and strong polyimide films could be obtained via the thermal curing of their precursor poly(amic acid) films. The polyimides showed high glass transition temperatures between 288°C and 318°C, and they did not show significant decomposition before 500°C in air or nitrogen atmosphere. Cyclic voltammograms of the polyimide films on the indium–tin oxide-coated glass substrate exhibited a pair of reversible oxidation waves with low onset oxidation potentials of 0.45–0.49 V (vs. silver/silver chloride) in acetonitrile solution. Upon oxidation, the color of the polyimide films changes from pale yellow to yellowish green and finally to blue.

Synthesis and properties of poly(amine-amide)s and poly(amine-imide)s based on 4,4′-diamino-4″-fluorotriphenylamine

Abstract Novel electroactive aromatic poly(amine-amide)s and poly(amine-imide)s with 4-fluorotriphenylamine units in the backbone were prepared from a newly synthesized diamine monomer, 4,4′-diamino-4″-fluorotriphenylamine, with aromatic dicarboxylic acids and tetracarboxylic dianhydrides via the phosphorylation technique and conventional two-step polycondensation technique, respectively. All the synthesized polymers could afford flexible and tough films with moderately high thermal stability. Cyclic voltammograms of the poly(amine-amide) and poly(amine-imide) films on the indium-tin oxide (ITO)-coated glass substrate exhibited a pair of reversible oxidation waves with oxidation half-wave potentials ( E 1/2 ) of 0.91–0.99 V and 1.19–1.23 V ( vs . Ag/AgCl), respectively, in an electrolyte/acetonitrile solution. They also exhibited obvious electrochromic behavior between their neutral and oxidized states changing from pale yellow to green or blue.

Synthesis and Characterization of New Organosoluble and Thermally Stable Polyimides Containing Pyridine and Anthracene Units

SummaryA series of new polyimides were obtained by the polycondensation reactions of the three diamines containing pyridine and anthracene units with various aromatic tetra carboxylic dianhydrides via both two‐step and one‐step methods. The precursors and monomers were characterized by elemental analysis, FT‐IR, 1H‐NMR and 13C‐NMR techniques. The structure of the polyimides was confirmed by FT‐IR, and 1H‐NMR spectroscopy, inherent viscosity and molecular weight measurements. All the polyimides are soluble in aprotic solvents such as NMP, DMF, DMAc and DMSO. These polyimides exhibit Tg in the range of 213–317 °C and 10% weight loss (T10) takes place in the range of 414‐531 °C in N2 401–521 °C in air and the char yield varies between 38–54%. The polymer films have tensile strength in the range of 84–110 MPa, elongation at break in the range of 11.2–13.8% and tensile modulus in the range of 1.1–1.4 GPa and low moisture absorption (0.87–1.16). All of these new polymers show excellent thermal stability and the polyimide films have good mechanical properties.

Synthesis and characterization of new redox-active and electrochromic polyimides with (4-morpholinyl)triphenylamine units

A series of electroactive aromatic polyimides with (4-morpholinyl)triphenylamine units in the backbone were prepared from a newly synthesized diamine monomer, 4,4′-diamino-4″-(4-morpholinyl)triphenylamine, and aromatic tetracarboxylic dianhydrides via the conventional two-step polycondensation technique. Flexible and tough polyimide films could be obtained via the thermal curing of their precursor poly(amic acid) films. The polyimides showed high glass-transition temperatures (Tg) between 290–313°C, and they did not show significant decomposition before 500°C in air or nitrogen atmosphere. Cyclic voltammograms of the polyimide films on the indium-tin oxide (ITO)-coated glass substrate exhibited a pair of reversible oxidation waves with low onset oxidation potentials of 0.43–0.53V (vs. Ag/AgCl) in acetonitrile solution. They also exhibited multicolor electrochromic behavior between their neutral and oxidized states changing from pale yellow to cyan and bluish purple.

Synthesis and electro-optical properties of aromatic polyamides and polyimides bearing pendent 3,6-dimethoxycarbazole units

This work deals with the synthesis and characterization of a new m-phenylenediamine-type monomer with pendent 3,6-dimethoxycarbazole group, namely N-(4-(3,6-dimethoxycarbazol-9-yl)phenyl)-3,5-diaminobenzamide (2), and its derived aromatic polyamides and polyimides. New electroactive aromatic polyamides were synthesized from diamine 2 with four aromatic dicarboxylic acids via the phosphorylation polyamidation technique, and the polyimides were prepared from equimolar mixtures of 4,4′-oxydianiline and diamine 2 with four aromatic tetracarboxylic dianhydrides via a conventional two-step procedure. All the polyamides and the 6FDA-derived polyimide were readily soluble in many organic solvents and could afford strong and flexible films by solution casting. The polymers showed useful levels of thermal stability with glass-transition temperatures (Tgs) in the range of 237–313°C and 10% weight-loss temperatures in excess of 450°C. All the polyamides and polyimides showed reversible electrochemical oxidation, accompanied by strong color changes. By incorporation of electron-donating methoxy groups on the electrochemically active C-3 and C-6 sites of the carbazole unit, the polymers exhibit greatly enhanced electrochemical stability and electrochromic performance in comparison with the analogs without any substituents on the carbazole unit.

Synthesis and electrochromic properties of novel aromatic fluorinated poly(ether-imide)s bearing anthraquinone units

Abstract A novel class of fluorinated poly(ether-imide)s (PEIs) with anthraquinone (AQ) units were prepared from the polycondensation reactions of a newly synthesized AQ-dietheramine monomer, namely 2,6-bis(4-amino-2-trifluoromethylphenoxy)-anthraquinone, with aromatic tetracarboxylic dianhydrides via a conventional two-step technique. The fluorinated polyimides exhibited enhanced solubility and optical transparency because of increased free volume caused by the CF 3 substituents. Furthermore, the PEIs showed high thermal stability, with glass-transition temperatures of 263–312 °C and decomposition temperatures in excess of 500 °C. These PEIs were also investigated by cyclic voltammetry and spectroelectrochemistry. Preliminary results reveal that these AQ-based PEIs are potentially useful as cathodically coloring red electrochromes.

Synthesis and characterization of optically active polyimides and their octa(aminophenyl)silsesquioxane nanocomposites

New optically active diamine (3,5-diaminophenyl)((R)-3,4-dihydro-1-phenylisoquinoline-2(1H)-yl)methanone was successfully prepared. Optically active polyimides (PIs) were synthesized by reacting the prepared diamine with the aromatic tetracarboxylic dianhydrides, namely, 3,3′,4,4′-benzophenone tetracarboxylic dianhydride/pyromelltic dianhydride by thermal imidization method and characterized using Fourier transform infrared and nuclear magnetic resonance spectral techniques. Additionally, PI nanocomposites were also prepared by incorporating amino-functionalized polyhedral oligomeric silsesquioxane named as octa(aminophenyl)silsesquioxane (OAPS). The cut-off wavelengths of PIs and their nanocomposites were found to be less than 350 nm, indicating that the PIs are transparent. The PIs and their nanocomposites were found to have glass transition temperature between 204°C and 269°C (differential scanning calorimetric analysis). The 10% weight loss temperature and char yield were found to be 319.5–420.3°C and 26.3–62.7%, respectively. The PIs were found to be amorphous as indicated by X-ray analysis. The scanning electron microscopic images of the nanocomposites also reveal uniform distribution of the nanoparticles in the nanocomposite. PIs and PI/OAPS nanocomposites were found to have low dielectric constant in the range of 2.59–3.36.

Ambipolar and multi-electrochromic polyimides based onN,N-di(4-aminophenyl)-N′,N′-diphenyl-4,4′-oxydianiline

A series of novel aromatic polyimides were synthesized from N,N-di(4-aminophenyl)-N′,N′-diphenyl-4,4′-oxydianiline and aromatic tetracarboxylic dianhydrides through a conventional two-step procedure. Most of the polyimides exhibited reasonable solubility in organic solvents and could afford robust films via solution casting. The polyimides exhibited high thermal stability, with glass transition temperatures in the range 227–273 °C and 10% weight-loss temperatures in excess of 550 °C. All the polyimide films showed ambipolar redox and multi-electrochromic behaviors. They exhibited two reversible oxidation redox couples at 0.94–0.98 and 1.09–1.12 V versus Ag/AgCl in acetonitrile solution. A coupling reaction between the radical cations of the pendent triphenylamine units occurred during the oxidative process forming a tetraphenylbenzidine structure which resulted in an additional redox state and color change. © 2014 Society of Chemical Industry

Synthesis and electrochromic properties of aromatic polyimides bearing pendent triphenylamine units

A series of aromatic polyimides with pendent triphenylamine group were synthesized from equimolar mixtures of 4,4′-oxydianiline (ODA) and 4-(3,5-diaminobenzamido)triphenylamine (4), 4-(3,5-diaminobenzamido)-4′,4″-di-tert-butyltriphenylamine (t-Bu-4) or 4-(3,5-diaminobenzamido)-4′,4″-dimethoxytriphenylamine (MeO-4) with two aromatic tetracarboxylic dianhydrides (DSDA or 6FDA) via a conventional two-step procedure that included a ring-opening polyaddition to give poly(amic acid)s, followed by chemical imidization. These polyimides exhibited good solubility in polar organic solvents and could be solution-cast into flexible and strong films. They showed excellent thermal stability, with Tg values in the range of 284–309 °C. The polyimides derived from diamines t-Bu-4 and MeO-4 exhibited reversible electrochemical oxidation, accompanied by strong color changes with high contrast ratio and electrochromic stability. For the polyimides derived from diamine 4, the coupling reaction between the triphenylamine radical cations occurred during the oxidative process forming a tetraphenylbenzidine structure, which resulted in an additional oxidation state and color change together with enhanced near-IR absorption at fully oxidized state.

Synthesis and electrochromic properties of aromatic polyetherimides based on a triphenylamine‐dietheramine monomer

ABSTRACTA series of electroactive polyetherimides (PEIs) with triphenylamine (TPA) units were prepared from the polycondensation reactions of 4,4′‐bis(p‐aminophenoxy)triphenylamine with aromatic tetracarboxylic dianhydrides via a conventional two‐step technique. The PEIs showed high thermal stability, with glass‐transition temperatures of 234–282 °C and decomposition temperatures in excess of 500 °C. They showed well‐defined and reversible redox couples during both p‐ and n‐doping processes, together with multielectrochromic behaviors. These polymers exhibited enhanced redox‐stability and electrochromic performance as compared with the corresponding analogs without the phenoxy spacer between the TPA and imide units. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2925–2938

Solution‐processable colorless polyimides derived from hydrogenated pyromellitic dianhydride with controlled steric structure

AbstractThis work presents novel colorless polyimides (PIs) derived from 1R,2S,4S,5R‐cyclohexanetetracarboxylic dianhydride (H″‐PMDA). Isomer effects were also discussed by comparing with PI systems derived from conventional hydrogenated pyromellitic dianhydride, that is, 1S,2R,4S,5R‐cyclohexanetetracarboxylic dianhydride (H‐PMDA). H″‐PMDA was much more reactive with various diamines than H‐PMDA, and the former led to PI precursors with much higher molecular weights. The results can be explained from the quite different steric structures of these isomers. The thermally imidized H″‐PMDA‐based films were colorless regardless of diamines because of inhibited charge‐transfer interaction. In particular, the H″‐PMDA/4,4′‐oxydianiline system simultaneously achieved a very high Tg exceeding 300 °C, high toughness (elongation at break > 70%), and good solution processability. In contrast, the H‐PMDA‐based counterparts were essentially insoluble. The outstanding solubility of the former probably results from disturbed chain stacking by its nonplanar steric structure. An advantage of chemical imidization process is also proposed. In some cases, a copolymerization approach with an aromatic tetracarboxylic dianhydride was effective to improve the thermal expansion property. The results suggest that the H″‐PMDA‐based PI systems can be promising candidates for novel high‐temperature plastic substrate materials in electronic paper displays. A potential application as optical compensation film materials in liquid crystal displays (LCD) is also proposed in this work. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013

Synthesis and properties of new aromatic polyimides containing redox‐active anthraquinone moieties

AbstractA novel anthraquinone‐containing bis(ether amine) monomer, 2,6‐bis(4‐aminophenoxy)anthraquinone, was synthesized from readily available reagents. A series of novel aromatic polyimides were prepared from the newly synthesized diamine monomer with various aromatic tetracarboxylic dianhydrides. The intermediate poly(amic acid)s had inherent viscosities of 0.67–1.12 dL g−1, and those derived from less stiff dianhydrides could be solution‐cast and thermally cyclodehydrated into flexible and tough polyimide films. The polyimides exhibited glass transition temperatures between 270 and 297 °C, and they were fairly stable up to a temperature of 500 °C in air or nitrogen. The electrochemical and electrochromic properties of one of the polyimides were investigated. The polymer could undergo two reversible steps of electrochemical reduction, with a color change from a colorless neutral state to pink and rose‐red reduced states. © 2012 Society of Chemical Industry

New Soluble Polyimides with High Optical Transparency and Light Color Containing Pendant Trifluoromethyl and Methyl Groups

AbstractA new aromatic diamine containing trifluoromethyl and methyl groups, namely α,α‐bis(4‐amino‐3‐methylphenyl)‐4‐(trifluoromethyl)phenylmethane (1), was synthesized from 2‐methylaniline and 4‐(trifluoromethyl)benzaldehyde. A series of fluorinated polyimides (PIs) were prepared from the diamine with four commercially available aromatic tetracarboxylic dianhydrides using a one‐step high‐temperature polycondensation procedure. These obtained PIs showed excellent solubility, with the dissolvability at a concentration of 10 wt% in most solvents, and they could afford flexible and strong films. Thin films of these PIs exhibited high optical transparency and light color, with the cutoff wavelength at 324–357 nm and transmittance higher than 74% at 450 nm. Moreover, these PIs possessed eminent thermal stability and good mechanical properties.