Imidization Of Poly Research Articles

Soluble, transparent and heat-resistant fluorinated copoly(ether imide)s containing pyridyl and biphenyl units in the main chain

A series of new fluorinated copoly(ether imide)s containing pyridyl and biphenyl moieties were prepared by thermal imidization of poly(amic acid)s derived from 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene (BATB), 4-(4-trifluoromethylphenyl)-2,6-bis(4-aminophenyl)pyridine (TFMPBPP) and 3,3’,4,4’-biphenyltetracarboxylic dianhydride with various mole ratios of BATB and TFMPBPP ranging from 80/20 to 20/80. All copoly(ether imide)s were amorphous and soluble in polar solvents such as N,N-dimethylacetamide and N-methyl-2-pyrrolidone at room temperature or upon heating at 70 °C, and displayed good thermal properties with gradually increasing of a glass transition temperature ranged from 282 to 347 °C as an increase of the TFMPBPP component, the temperature at 5% weight loss of 574–586 °C, and the residue of 57–62% at 750 °C in nitrogen. Tough and flexible polymer films also exhibited outstanding mechanical properties with tensile strengths of 109.1–111.9 MPa, tensile moduli of 1.3–1.5 GPa, and elongations at break of 27.9–48.7%, low dielectric constants of 2.98–3.15 (1 MHz) and water uptake 0.36–0.55%, as well as high optical transparency with the UV-vis cutoff wavelength in the 370–382 nm range and the wavelength of 80% transparency in the range 518–550 nm.

Syntheses of Soluble Biopolyimides Using 4-Aminophenylalanine

4-Aminophenylalanine (4APhe), an exotic amino acid which is obtained as a microorganism metabolite of glucose, is polycondensed with various tetracarboxylic dianhydrides as a diamine monomer to obtain poly(amic acid)s. Subsequent thermal imidization of poly(amic acid)s is made at 220 °C with stepwise heating from 100 °C. Some of the obtained polyimides (PIs) exhibited good solubility in organic solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and more. The progress of imidization was observed by proton nuclear magnetic resonance and infrared spectroscopy to confirm that the imidization ratio was up to 98%. Carboxylate group of the side-chains of PIs affected their solubilities despite the high imidization ratio, and the solubility was lost for any organic solvents by decarboxylation at 280 °C, confirmed from mass-loss of thermogravimetric analysis. Thus, a new series of PIs were obtained with abilities of solvent-molding in PI state and thermal resistivity enhancement by further heating after molding.

Enhancement of the Mechanical Properties of Polyimide Film by Microwave Irradiation.

Polyimide films have conventionally been prepared by thermal imidization of poly(amic acid)s (PAAs). Here we report that the improvement of tensile strength while increasing (or maintaining) film flexibility of polyimide films was accomplished by simple microwave (MW) irradiation of the PAAs. This improvement in mechanical properties can be attributed to the increase in molecular weight of the polyimides by MW irradiation. Our results show that the mechanical properties of polyimide films can be improved by MW irradiation, which is a green approach that requires relatively low MW power, very short irradiation time, and no incorporation of any additional inorganic substance.

Polyimides Containing Phosphaphenanthrene Skeleton: Gas-Transport Properties and Molecular Dynamics Simulations.

A series of new semifluorinated polyimide (PI) films with phosphaphenanthrene skeleton were prepared by thermal imidization of poly(amic acid)s derived from a diamine monomer: 1,1-bis[2′-trifluoromethyl-4′-(4″-aminophenyl)phenoxy]-1-(6-oxido-6H-dibenz⟨c,e⟩⟨1,2⟩oxaphosphorin-6-yl)ethane on reaction with four structurally different aromatic dianhydrides. The chemical structures of the polymers were established by Fourier transform infrared and 1H NMR spectroscopy techniques. The polymers showed a good combination of thermal and mechanical properties (Td10 up to 416 °C under synthetic air and tensile strength up to 91 MPa), low dielectric constant (2.10–2.55 at 1 MHz), and Tg values as high as 261 °C. Gas permeabilities of these films were investigated for four different gases CO2, O2, N2, and CH4. The PI films showed high gas permeability (PCO2 up to 175 and PO2 up to 64 barrer) with high permselectivity (PCO2/PCH4 up to 51 and PO2/PN2 up to 7.1), and the values are better than those of many other similar polymers reported earlier. For the O2/N2 gas pair, the PIs (PI A) surpassed the present upper boundary limit drawn by Robeson. A detailed molecular dynamics (MD) simulation study has been conducted to understand better the gas-transport properties. The effect of phosphaphenanthrene skeleton, its spatial arrangement, and size distribution function of the free volume were studied using molecular dynamics (MD) simulation and the results are correlated with the experimental data.

Nanoparticle Structures with (Un-)Hydrogenated Castor Oil as Hydrophobic Paper Coating.

The encapsulation of vegetable oils within an aqueous dispersion of polymer nanoparticles provides an alternative route to create functional paper coatings from renewable resources, by combining the presentation of hydrophobic moieties together with variations in roughness at the paper surface. The effects of two selected vegetable oil types, i.e., castor oil and hydrogenated castor oil (wax), are compared in terms of nanoparticle synthesis, coating hydrophobicity and surface gloss. The nanoparticles were synthesized by adding 50 wt.-% oil during imidization of poly(styrene-co-maleic anhydride) with ammonium hydroxide. From evaluation of the thermal properties, the nanoparticles have a high glass transition temperature that is suppressed in presence of oil. The nanoparticles with hydrogenated castor oil have higher imide content and better thermal stability compared to castor oil, in parallel with lower chemical reactivity of the hydrogenated oil and less interference with the imidization reaction. After deposition as a coating on paper, the physical coating properties are discussed in parallel with the coating chemistry and morphology or roughness at different scale lengths. The nanoparticle coatings with hydrogenated oil provides a multi-scale roughness with an open, porous nanoparticles structures and presentation of some amount free oil augmenting hydrophobicity towards a water contact angle of 128° (static contact angle) or 138° (advancing contact angle). The differences in surface coverage of coated papers in terms of imide and oil contents are confirmed by chemical Raman mapping. The differences in surface roughness are confirmed by non-contact profilometry, laser interferometry and atomic force microscopy.

The effect of solvent to the kinetics of imidization of poly(amic acid)

Kinetics of the imidization reaction of poly (amic acid) (PAA) film based on pyromellitic anhydride (PMDA) and 4,4′-diaminodiphenyl ether (ODA) was studied by infrared spectroscopy. Attention is paid to the effect of solvent content inside the sample to the reaction kinetics. The results show that the presence of solvent favors the imidization reaction, rendering a much higher reaction kinetics than the case of without solvent. The data indicates that there is almost one NMP solvent molecule lost per imidization reaction. The kinetics of isothermal imidization reaction exhibits huge heterogeneity and is well-fitted by the Kohlraush-Williams-Watts (KWW) equation, from which the characteristic reaction time and the stretching exponent are determined. Both of them decrease with the increasing of the imidization reaction temperature, demonstrating the reaction is retarded with the proceeding of the reaction together with the creation of bigger dynamical heterogeneity.

Polytriazoleimide/Graphene oxide nanocomposites and their properties

Polyimide containing 1, 2, 3‐triazole ring (Polytriazoleimide)–Graphene oxide (GO) nanocomposites were synthesized by thermal imidization of poly(amic acid) containing 0.5 to 3 wt% GO. Polytriazoleimide (PTAI)/GO nanocomposites were characterized by X‐ray diffraction (XRD), raman spectroscopy, thermogravimetric analysis, transmission electron microscopy, scanning electron microscopy, and atomic force microscopy. The formation of GO was confirmed by Raman spectroscopy and XRD. The good mechanical properties of the PTAI/GO nanocomposites were attributed to good dispersion and effective stress transfer between the polymer and GO sheets, as evidenced by the results from XRD and morphological studies. Dynamic mechanical analysis of PTAI/GO shows an improvement in the storage modulus from 3.54 to 4.14 GPa and an improvement in the glass transition temperature from 255 to 263°C. PTAI/GO nanocomposites showed good dielectric constant (ɛ′ was found to be in the range of 2.96–3.46) and low dielectric loss (ɛ″ was found to be in the range of 0.38–0.09) at 1 MHz. Thermogravimetric analysis also shows increase in thermal stability with increasing GO content. POLYM. COMPOS., 39:2202–2211, 2018. © 2016 Society of Plastics Engineers

Synthesis and properties of low coefficient of thermal expansion copolyimides derived from biphenyltetracarboxylic dianhydride with p-phenylenediamine and 4,4′-oxydialinine

Abstract A series of copolyimides were prepared by thermal imidization of poly(amic acid)s (PAAs) derived from 3,3′,4,4′-biphenyltetracarboxylic dianhydride (s-BPDA), 2,3′,3,4′-biphenyltetracarboxylic dianhydride (a-BPDA), p-phenylenediamine (PDA) and 4,4′-oxydialinine (4,4′-ODA) commonly used for the production of commercial polyimides. The flexible copolyimide films were obtained from that the molar ratio of s-BPDA, a-BPDA, PDA and 4,4′-ODA was 9:1:8:2 (Co-PIs-3), 8:2:9:1 (Co-PIs-5) and 8:2:8:2 (Co-PIs-6). These obtained copolyimide films were characterized by Fourier transform-infrared spectroscopy(FT-IR), wide angle X-ray (WAXD), Thermogravimetric (TG), dynamic mechanical thermal analysis (DMA), thermomechanical analysis (TMA), field-emission scanning electron microscopy (FE-SEM) and mechanical properties measurement. The results showed that three copolyimides remained semi-crystalline and exhibited high glass transition temperature (Tg), high thermal stability, great ultimate tensile strength and low coefficient of thermal expansion (CTE). The Co-PIs-5 had lower crystallinity, lower CTE, greater elongation at break, higher Tg and thermal stability and the greater dense extent, compared with Co-PIs-3 and Co-PIs-6. Structure and property relations of the prepared polyimides were also briefly discussed. The results revealed that the copolymerization of s-BPDA/PDA with a small number of 4,4′-ODA/a-BPDA was a useful means for enhancing flexibility without sacrificing low CTE.

Tuning thermal release kinetics of soy oil from organic nanoparticles using variable synthesis conditions

The thermal release properties of soy oil from poly(styrene-co-maleimide) nanoparticles containing 50wt% encapsulated oil have been quantified as a function of temperature and time. The effects of different synthesis conditions on the thermal stability of the nanoparticles and their oil release have been evaluated, i.e., by gradually increasing the amount of ammonium hydroxide used for the imidization of poly(styrene-co-maleic anhydride). First, the intrinsic thermal properties of the oil-filled nanoparticles were analysed by differential scanning calorimetry, which revealed an exothermal reaction related to the oil release and a suppression of the glass transition that may be masked owing to the complex structure of the hybrid nanoparticles. The isothermal scans showed different rates of oil release after a post-imidization reaction. The oil release was better followed by dynamic mechanical analysis, which illustrated changes in visco-elastic properties expressed by the maximum in the loss factor that related to the amount of released oil. Depending on the amount of ammonium hydroxide, the oil started to release below the glass transition temperature at various rates. Thermal release profiles of the oil were quantified by infrared and Raman spectrocopy after heating for 2min to 6h at 125 to 250°C, based on variations in oil-related and imide-related absorption bands. The oil release increased below and above the glass transition temperature, following a parabolic trend, and progressively decreased at higher ammonium hydroxide concentrations, in parallel with higher imide content and changes in imide conformation. The kinetics and mechanism of the oil release can be described by the Korsmeyer–Peppas model, suggesting a dominating diffusion mechanism that is influenced by further imidization of the polymer matrix during heating.

Reaction efficiency and retention of poly(styrene-co-maleimide) nanoparticles deposited on fibrillated cellulose surfaces

Surface modification of micro- and nanofibrillated cellulose (MFC and NFC) under aqueous environment was performed by deposition of poly(styrene-co-maleimide) nanoparticles synthesized by imidization of poly(styrene-co-maleic anhydride) in presence of wax and ammonium hydroxide in variable amounts. Specifically, the influences of fiber fibrillation on nanoparticle formation (i.e., reaction efficiency) and permanent nanoparticle deposition on the fiber surface (i.e., retention) were investigated. The surface modification was mainly governed by the fiber diameter, surface charges and amount of wax. As such, the MFC affected the imidization reaction to a smaller extent (i.e., high reaction efficiency) and was more densely deposited by nanoparticles than NFC (i.e., high retention). Moreover, wax protected the fibers against fibrillation and peeling-off at high temperature and favored nanoparticle deposition. As a result, water contact angles of 142° were obtained for modified MFC in parallel with a surface coverage of 92%.

Prevention of void formation in particulate-filled polymer composites: Effects of thermoplastic matrices and residual solvent

One of the key concerns in fabrication of particulate-filled polymer composites using polyimide (PI) as a matrix is formation of voids due to entrapment of water during thermal imidization of poly(amic acid) (PAA) precursor. Using hexagonal boron nitride (hBN) flakes as the filler material, this study investigated the effects of thermoplastic PI and fabrication conditions on morphological structures of hBN/PI composite films, in particular void fraction ϕv. A decrease in ϕv was observed in thermoplastic PI composites in comparison with its thermosetting counterpart. The morphological factors analyzed by SEM and WAXD showed a good correlation with the out-of-plane thermal diffusivity. A substantial decrease in ϕv was further achieved by using a solvent with higher boiling point and by shortening the drying time to increase the residual solvent in the hBN/PAA precursor films, from which the remaining solvent was eliminated during the final imidization step. Under optimized conditions, ϕv < 3% at 60 vol% hBN content was achieved through lowered glass transition temperatures of the precursor and the plasticizing effect of the solvent.

Kinetic study of low‐temperature imidization of poly(amic acid)s and preparation of colorless, transparent polyimide films

ABSTRACTConventional synthesis of polyimides includes high‐temperature (160–350 °C) imidization of poly(amic acid)s. In the present work, imidization has been carried out at much lower temperatures (40–160 °C). 1,2,4,5,‐cyclohexanetetracarboxylic dianhydride (HPMDA) or pyromellitic dianhydride (PMDA) was polymerized with an aromatic diamine, 4,4′‐diaminodiphenylmethane (DDPM), to give poly(amic acid)s, which were then imidized chemically. Imidization was more than 90% complete even at the very low imidization temperature of 40 °C. It was found that the imidization occurs in two steps: an initial rapid cyclization and a subsequent slower cyclization. The activation energy for the rapid process was determined to be 4.3 kJ/mol, and that of the slower process, 4.8 kJ/mol. As the imidization temperature decreases, the transmittance of the resulting polyimides tends to gradually increase, the cutoff wavelength decreases and the color becomes pale. A partially aliphatic polyimide based on HPMDA and DDPM prepared at 40 °C yielded thin films that were highly transparent and colorless, and had good flexibility, solubility and thermal stability. The polyimide films prepared in this study may be good candidates for flexible, transparent plastic substrates in the display industry. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 1593–1602

Thermal release of vegetable oils loaded in hydrophobic polymer nanoparticles

The encapsulation of vegetable oils during imidization of poly(styrene‐co‐maleic anhydride) provides stable aqueous dispersions of oil‐filled nanoparticles with 50 wt% oil. The functionality of nanoparticles with soy‐, corn‐, rapeseed‐, sunflower‐, castor‐, and hydrogenated castor‐oil, can be controlled by thermal release upon heating at 120–250°C for 2 min to 6 h. In a first part, the intrinsic thermal properties of the nanoparticles have been determined by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). The differences in calculated imide content illustrate that the transition phenomena depend on complex interactions between the oil and imide phase. The TGA results show that bursting of the particles is not a main release mechanism while the oil is either progressively released below or above the glass transition temperature, which is best monitored by DMA. In a second part, the release profiles are determined from FTIR and Raman spectra following different trends according to the type of encapsulated oil and nanoparticle morphology, i.e., solid, nanoporous, cauliflower‐like, or true core‐shell. Also the interference with imidization during heating influences the oil release. The kinetics and mechanism of oil release can be systematically described after fitting with mathematical models.Practical applications: The nanoparticles can be incorporated as coating pigments for packaging paper or used for surface functionalization of natural fibers, where controlled release of the oil provides a required degree of hydrophobicity.Different types of vegetable oil were incorporated in imidized nanoparticles, resulting in various particle morphologies (e.g., solid, nanoporous, cauliflower‐like, or true core‐shell) with characteristic release profiles of the oil as a function of temperature and time.

Kaolinite Nanocomposite Platelets Synthesized by Intercalation and Imidization of Poly(styrene-co-maleic anhydride).

A synthesis route is presented for the subsequent intercalation, exfoliation and surface modification of kaolinite (Kln) by an imidization reaction of high-molecular weight poly(styrene-co-maleic anhydride) or SMA in the presence of ammonium hydroxide. In a first step, the intercalation of ammonolyzed SMA by guest displacement of intercalated dimethylsulfoxide has been proven. In a second step, the imidization of ammonolyzed SMA at 160 °C results in exfoliation of the kaolinite layers and deposition of poly(styrene-co-maleimide) or SMI nanoparticles onto the kaolinite surfaces. Compared with a physical mixture of Kln/SMI, the chemically reacted Kln/SMI provides more efficient exfoliation and hydrogen bonding between the nanoparticles and the kaolinite. The kaolinite nanocomposite particles are synthesized in aqueous dispersion with solid content of 65 wt %. The intercalation and exfoliation are optimized for a concentration ratio of Kln/SMI = 70:30, resulting in maximum intercalation and interlayer distance in combination with highest imide content. After thermal curing at 135 °C, the imidization proceeds towards a maximum conversion of the intermediate amic acid moieties. The changes in O–H stretching and kaolinite lattice vibrations have been illustrated by infrared and FT-Raman spectroscopy, which allow for a good quantification of concentration and imidization effects.

Rylene bisimide-based nanoparticles with cross-linked core and thermoresponsive shell using poly(vinyl amine)-based block copolymers

Rylene bisimide-based nanoparticles with cross-linked core were synthesized by site-selective cross-linking and self-assembly of block copolymer composed of poly(N-vinyl amine) and poly(N-isopropylacrylamide), which was prepared by RAFT polymerization. Single-step imidization of poly(vinyl amine)-b-poly(NIPAM) with arylene dianhydride derivatives, including naphthalene-1,8:4,5-tetracarboxylic dianhydride and perylene-3,4:9,10-tetracarboxylic dianhydride, afforded nanoparticles with naphthalene bisimide core (NP-NBI) and perylene bisimide core (NP-PBI), respectively. DLS analysis demonstrated that the size of cross-linked nanoparticles was uniform and could be controlled by the imidization conditions. UV–vis, fluorescence, and cyclic voltammetry measurements led to the optical and electrochemical properties derived from NBI and PBI units in the cross-linked nanoparticles, supporting the successful preparation of desired nanoparticles.

Catalysis and inhibition of benzimidazole units on thermal imidization of poly(amic acid) via hydrogen bonding interactions

The effect of benzimidazole units on thermal imidizaiton was studied when they were introduced into the main chain of poly(amic acid) (PAA). The thermal imidization process of PAA-PABZ synthesized by 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA) and 2-(4-aminophenyl)-5(6)-aminobenzimidazole (PABZ) was studied by TGA, DSC, DMA, FTIR and in situ FTIR. The results of FTIR and in situ FTIR indicate benzimidazole units act as an “in situ” catalyst to accelerate thermal imidization of PAA to polyimide (PI) when the temperature is lower than 170 °C. FTIR and 1H-NMR results demonstrate that in situ catalysis is caused by the hydrogen bonding interactions between C=N of benzimidazole and -NH- in -CONH- of PAA and the semi-ionization of the H in imidazole ring of benzimidazole. However, when the imidization temperature is higher than 170 °C, the thermal imidization process is inhibited. DMA and in situ FTIR results illustrate that the decreased mobility of PI-PABZ macromolecular chains and the reduced reactive ability of anhydride formed during the intramolecular breakdown of polymer chains lead to the inhibition of thermal imidization process.

Synthesis of imidized nanoparticles containing soy oil under various reaction conditions

The imidization of poly(styrene-co-maleic anhydride) nanoparticles in presence of soy oil was studied, resulting in the formation of nanoparticles with 20–80nm diameter with a porous structure allowing to incorporate 50wt.% soy oil. The reaction efficiency strongly depends on the amount of ammonium hydroxide as imidizing agent, which ratio was varied between 1.01 and 1.60 relatively to the maleic anhydride moieties. Finally, stable aqueous dispersions are obtained with a higher solid content and somewhat higher Zetapotential compared to purely imidized nanoparticles. There are concurring reactions between imidization and coupling of the unsaturated double bonds in soy oil to the ammonolysed maleic anhydride. Therefore, a large amount of non-embedded oil was only observed when the imidization is favoured under high concentrations of ammonium hydroxide. Using spectroscopy and thermal analysis, it is concluded that a complex organized nanostructure is formed between the poly(styrene-co-maleimide) and soy oil, which results in a suppression of Tg evaluated by (temperature-modulated) differential scanning calorimetry.

Effect of polymer structure on the morphologies and dielectric properties of nanoporous polyimide films

ABSTRACTLow dielectric constant polyimide (PI) films have potential applications in integrated circuit. In this study, poly(methyl methacrylate), poly(ethylene oxide), and polystyrene as thermally labile materials were used as templates to generate PI films with nanopores by first mixing the polymer templates with the precursor of PI, poly(amic acid), followed by imidization of poly(amic acid) together with degradation of the polymer templates. The sizes of the formed pores, the thermal and dielectric constant of the nanofoamed PI films were studied and compared in detail. It is concluded that the dielectric constant of PI films using poly(ethylene oxide) as pore template is more stable because of the formation of uniform pores which is from the great accordance of imidization temperature of poly(amic acid) with the degradation temperature of poly(ethylene oxide). But that using poly(methyl methacrylate) as pore template is frequency dependent as the influence of inhomogeneous pores and PMMA residue from incompletely degradation of poly(methyl methacrylate). © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41480.

Preparation of porous carbon materials by using coagulated polyamic acid precursor

In recent years, porous carbon materials have received a great deal of attention due to their many applications. Especially, activated carbon materials are potentially of great technological interest for the development of catalytic, electronic, fuel cells, and hydrogen storage systems. However, there are many complex and risky chemical activation process for improving the surface area of carbon materials. Polyimides (PIs), which are synthesized by the thermal imidization of poly(amic acid) (PAA) precursors, have been adapted as a carbonization precursors because of their high carbonization yield and homogeneously shrinking property during carbonization. From these reasons, many kinds of carbon materials as like highly oriented graphite films, macroporous carbons, and carbon thin membranes are prepared from PIs. In this study, we demonstrated a new preparation method of porous carbon from a polyamic acid precursor without any chemical activation process. We prepared porous 6FDA-HAB PAA with coagulation method (Scheme I). By virtue of the high carbonization yield and homogeneous shrinking properties of 6FDA-HAB PAA, we successfully manufactured carbon materials with a porous channel structure. The structured carbon materials showed a high surface area of 1668 m/g.

Electrochromism Properties of Polyimides Possessing Triphenylamine Moieties with Different Substituents

Two diamine monomers with methyl (CH3TPA) and methoxy (OCH3TPA) group substituents in the para position of the triphenylamine (TPA) moiety were synthesized by nucleophilic aromatic substitution using 4-fluoronitrobenzene with p-toluidine and p-anisidine, respectively. From these diamine monomers, electroactive polyimides (PI)s were prepared by the chemical imidization of poly(amic acid) solutions, which were prepared with 4,4′-oxydiphthalic anhydride (ODPA). 1H nuclear magnetic resonance and Fourier transform infrared spectroscopy confirmed that both PIs had been synthesized successfully. The measured inherent viscosity for ODPA-CH3TPA PI and ODPA-OCH3TPA PI was 0.42 and 0.49 dL/g, respectively. The glass transition temperatures for ODPA-CH3TPA PI and ODPA-OCH3PDA PI were 236°C and 238°C, respectively, and the thermal degradation temperature of both PIs was above 390°C. The band gaps of ODPA-CH3PDA and ODPA-OCH3PDA were 3.00 and 2.72 eV, respectively. The oxidation onset potential Eox of ODPA-CH3PDA PI and ODPA-OCH3PDA PI from cyclic voltammetry was 0.73 V and 0.65 V, respectively. The highest occupied molecular orbital and lowest unoccupied molecular orbital values differed according to the groups substituted into the triphenylamine moiety. After applying a voltage, the absorption peak intensity at 723 nm and 752 nm for ODPA-CH3TPA and ODPA-OCH3TPA, respectively, increased. The electrical properties varied according to the chemical structure of synthesized diamines.