全氟羧酸酯乙烯基醚的合成研究

全氟羧酸酯乙烯基醚用于多种含氟聚合物的改性,合成全氟羧酸离子交换树脂等高性能含氟聚合物,也可以合成含氟醚类的绿色可降解表面活性剂。采用3-羧酸甲酯全氟丙酰氟与六氟环氧丙烷进行加成反应,然后脱羧制备全氟羧酸酯乙烯基醚。     

Organosoluble and light‐colored fluorinated polyimides derived from 5,5′‐bis[4‐(4‐amino‐2‐trifluoromethylphenoxy) phenyl]‐4,7‐methanohexahydroindan

A novel bis(ether amine) monomer, 5,5′‐bis[4‐(4‐amino‐2‐trifluoromethylphenoxy)phenyl]‐4,7‐methanohexahydroindan ( 2 ), was synthesized through the nucleophilic aromatic substitution reaction of 5,5′‐bis‐(4‐hydroxyphenyl)‐4,7‐methanohexahydroindan with 2‐chloro‐5‐nitrobenzotrifluoride to yield the intermediate dinitro compound, followed by catalytic reduction with hydrazine and Pd/C. A series of polyimides were synthesized from 2 and various aromatic dianhydrides using a standard two‐stage process with chemical or thermal imidization of poly(amic acid). All of these polymer films were soluble in amide‐type solvents above 10% w/v, had tensile strengths of 97–117 MPa, and the 10% weight loss temperature was above 464 °C with their residues exceeding 46% at 800 °C in nitrogen. Compared with the non‐fluorinated polyimides, the fluorinated series were observed to have lower dielectric constants (2.92–3.28 at 1 MHz) and lower moisture absorptions (0.15–0.43 wt%) as well as lower color intensity and better solubility. Copyright © 2006 Society of Chemical Industry     

Facile method towards functionalization of partially fluorinated polyarylethers via sequential post-polymerization modification

A novel partially fluorinated arylene vinylene ether (FAVE) polymer containing ester groups was synthesized, which was used to prepare three reactive FAVE polymers containing carboxylic acid groups, alcohol groups, and acid chloride groups, respectively. Post-polymerization modifications of the FAVE polymer's carboxylic acid groups (via a DCC coupling procedure with the desired alcohol), alcohol groups (via DCC coupling or an acid chloride esterification procedure with the desired carboxylic acid or acid chloride), and acid chloride groups (via an optimized nucleophilic substitution reaction with the desired alcohol or amine) were successfully performed. Several examples have been successfully prepared to demonstrate the versatility of these developed modification methods. FAVE polymers have been prepared with NHS active ester groups, Disperse Red 1 chromophores, benzyl bromide groups, aryl trifluorovinyl ether groups, ATRP initiator groups, vinyl groups, propargyl groups, Disperse Orange 3 chromophores, and benzaldehyde groups. In most cases, analytical data are consistent with a quantitative conversion of the reactive or functional groups. It is demonstrated that no degradation of the FAVE polymer matrix occurs after multistep post-polymerization modification reactions.     

Surface Fluorination of Poly(fluorenyl ether ketone) Ionomers as Proton Exchange Membranes for Fuel Cell Application

A series of sulphonated poly(fluorenyl ether ketone) ionomers were successfully fluorinated by the means of direct surface fluorination. Polymer ionomer samples in two different states (membrane and powder) were treated with F₂ gas which is diluted in N₂ in a special reactor. X‐ray photoelectron spectroscopy (XPS) was used to examine the F/C ratios of the fluorinated materials. The results revealed that the fluorination only occurred on the membrane surface and the fluorination degree increased with increasing F₂ concentration in N₂. The membrane subjected to fluorination shows an obviously enhanced oxidative stability. The endurance in a Fenton's reagent of FSPFEK‐P‐28 is longer than 180 min which is two times longer than that of un‐fluorinated SPFEK. The PEM properties and single fuel cell performances were investigated by comparison of un‐ and fluorinated polymer ionomers. The fluorinated membranes demonstrated an enhanced hydrophobic surface property, increased proton conductivities and better single fuel cell performances. Surface fluorination provides a convenient and useful approach to prepare highly proton conductive membrane with long life‐time PEM fuel cell applications.     

Light‐colored fluorinated polyimides based on 2,5‐bis(4‐amino‐2‐trifluoromethylphenoxy)biphenyl and various aromatic dianhydrides

A novel trifluoromethyl‐containing aromatic diamine monomer, 2,5‐bis (4‐amino‐2‐trifluoromethylphenoxy)biphenyl (2), was prepared through the nucleophilic substitution reaction of 2‐chloro‐5‐nitrobenzotrifluoride and phenylhydroquinone in the presence of potassium carbonate to yield the intermediate dinitro compound (1), followed by catalytic reduction with hydrazine and Pd/C. A series of fluorinated polyimides (code 5a–f) were synthesized from diamine (2) with six commercially available aromatic dianhydrides using a standard two‐stage process with thermal or chemical imidization of poly(amic acid). Most of fluorinated polyimides showed good solubility at a concentration of 5–10 wt % and even in pyridine and dioxane. For improving solubility of 5c, copolyimides (5c/a–f) were also prepared from 2 and a pair of dianhydrides (3c/a–f), which were mixed in the molar ratio 1:1. All the polyimide films had a tensile strength in the range from 73 to 112 MPa, an elongation at break within a range of 9–23%, and an initial modulus in the range of 1.6–2.2 GPa. These polyimides exhibited glass transition temperatures of 220–267°C and showed no significant decomposition below 500°C under either nitrogen or air atmosphere. In comparison with the analogous nonfluorinated polyimides based on 2,5‐bis (4‐aminophenoxy) biphenyl (2′), the fluorinated polyimides showed better solubility as well as reduced color intensity, lower dielectric constant, and moisture absorption. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4101–4110, 2006     

Enhancement of the chemical resistance of nitrile rubber by direct fluorination

Nitrile rubber (NBR), poly(acrylonitrile‐co‐butadiene) or NBR packers, are used to seal oil‐well tubing, where they often come into contact with ZnBr₂ brines at high temperatures and pressures. Under these conditions, NBR exhibits accelerated chemical degradation, which results in embrittlement and cracking. Although alternative fluoropolymers exhibit excellent chemical resistance, their strength is less than NBR, and replacement of the usual gasket materials with fluoroelastomers is expensive. We have demonstrated that a fluoropolymer surface on a nitrile elastomer provides the necessary chemical resistance while the elastomer retains strength. This can be achieved by direct fluorination, a rather easy and inexpensive process. Samples of NBR O‐rings were fluorinated by exposure to F₂ and F₂/HF mixtures at various temperatures. Although fluorination by F₂ produced the desired fluoropolymer layer, fluorination by F₂/HF (hydrofluoric acid) mixtures gave a smoother fluorinated layer at lower temperatures and shorter reaction times. Elemental analysis showed that the fluorinated layer eliminated ZnBr₂ diffusion into the NBR polymeric matrix. Surface fluorination also significantly retarded the loss of the mechanical properties of NBR when it was exposed to zinc bromide fluid. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 971–979, 2003     

Catalytic Performance of Nanoscopic,Aluminium Trifluoride‐Based Catalysts in the Synthesis of (all‐rac)‐α‐Tocopherol

A novel nanoscopic, partly hydroxylated aluminium fluoride was prepared in a sol‐gel fluorination synthesis and characterised by IR probe molecules. It was shown that this material has, in contrast to high surface area aluminium fluoride (HS‐AlF₃) which is one of the strongest Lewis acids, a low amount of strong Lewis acid sites combined with weak and medium strength Brønsted sites. Both materials were tested in the synthesis of (all‐rac)‐α‐tocopherol through the condensation of 2,3,6‐trimethylhydroquinone (TMHQ) with isophytol (IP). The activity data indicate the partly hydroxylated aluminium fluoride to be a very efficient and highly selective catalyst for (all‐rac)‐α‐tocopherol (>99.9%, for an IP conversion of 100%) whereas high surface area aluminium fluoride is a poor catalyst for this reaction.     

Synthesis and properties of novel aromatic poly(ester–amide)s derived from 1,5‐bis(3‐aminobenzoyloxy)naphthalene and aromatic dicarboxylic acids

A new naphthalene‐ring‐containing bis(ester–amine), 1,5‐bis(3‐aminobenzoyloxy)naphthalene, was prepared from the condensation of 1,5‐dihydroxynaphthalene with 3‐nitrobenzoyl chloride followed by catalytic hydrogenation. A series of novel naphthalene‐containing poly(ester–amide)s was synthesized by direct phosphorylation polyamidation from this bis(ester–amine) with various aromatic dicarboxylic acids. The polymers were produced in high yields and had moderate inherent viscosities of 0.47–0.81 dL g^?1. The poly(ester–amide) derived from terephthalic acid was semicrystalline and showed less solubility. Other polymers derived from less rigid and symmetrical diacids were amorphous and readily soluble in most polar organic solvents and could be solution‐cast into transparent, flexible and tough films with good mechanical properties. The amorphous poly(ester–amide)s displayed well‐defined glass transition temperatures of between 179 and 225 °C from differential scanning calorimetry and softening temperatures of between 178 and 211 °C from thermomechanical analysis. These poly(ester–amide)s did not show significant decomposition below 400 °C in nitrogen or air. Copyright © 2004 Society of Chemical Industry     

“Smart” membrane materials: Preparation and characterization of PVDF‐g‐PNIPAAm graft copolymer

In this research, a smart membrane material of graft copolymer of poly(vinylidene fluoride) with poly(N‐isopropylacrylamide) (PVDF‐g‐PNIPAAm) was synthesized by atom transfer radical polymerization (ATRP) using poly(vinylidene fluoride) (PVDF) as a macroinitiator and direct initiation of the secondary fluorinated site PVDF facilitates grafting the N‐isopropylacrylamide comonomer. The copolymers were characterized by Fourier transform infrared (FTIR), ¹H NMR, gel‐permeation chromatography (GPC), and X‐ray photoelectron spectroscopy (XPS). The temperature‐sensitive membrane was prepared from the PVDF‐g‐PNIPAAm graft copolymers by the phase inversion method. The effects of temperature on the flux of pure water of membrane was investigated. The results showed that alkyl fluorides were successfully applied as ATRP initiators in the synthetic condition and the flux of pure water through the PVDF‐g‐PNIPAAm membrane depended on the temperature change. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1482–1486, 2007     

Designing of fullers‐earth‐containing poly(vinyl alcohol)‐g‐poly(2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid) nanocomposites: Swelling and deswelling behaviors

In this study, polymer–clay nanocomposites (PCNs) composed of poly(vinyl alcohol)s (PVAs), poly(2‐acrylamido‐2‐methyl‐1‐propane sulfonic acid), and fullers earth were prepared by the effective dispersal of inorganic nanoclays in the organic PVA matrix via in situ free‐radical polymerization with potassium persulfate as an initiator and N,N‐methylene bisacrylamide as a crosslinker. The monomer, 2‐acrylamido‐2‐methyl‐1‐propane sulfonic acid, was grafted onto the PVA backbone, and at the same time, fullers earth layers were intercalated and exfoliated into the grafted copolymer, especially at a low or moderate loading of the fullers earth. The synthesized PCN materials were characterized by Fourier transform infrared spectroscopy and wide‐angle X‐ray diffraction techniques. The morphological features of the synthesized materials were studied by scanning electron microscopy; this revealed that the swelling ratio of this nanocomposite increased with increasing fullers earth content. The X‐ray diffraction results indicated that the fullers earth was exfoliated in the nanocomposite matrix, and its introduction into the polymer matrix enhanced the percentage crystallinity of the polymer. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Oxidative Desulfurization‐Fluorination: A Facile Entry to a Wide Variety of Organofluorine Compounds Leading to Novel Liquid‐Crystalline Materials

The oxidative desulfurization‐fluorination reaction of organosulfur compounds using an N‐haloimide and a fluoride source is demonstrated to be an effective and mild fluorinaton method that allows us to synthesize in high yields with high chemoselectivity various types of gem‐difluoro compounds, trifluoromethyl‐substituted (hetero)aromatics, trifluoromethyl ethers, and N‐trifluoromethylanilines. Herein briefly summarized are the synthetic procedures as well as the scope and limitations of the reaction. The applicability of the reaction is demonstrated by the synthesis of a difluorinated glutamic acid and novel liquid‐crystalline materials having an N‐trifluoromethylamino, trifluoromethoxy, or 1,2‐difluoroethylene group. The fluorine‐containing liquid‐crystalline materials are compared with the corresponding non‐fluorinated materials in respect to phase transition behaviors and electro‐optical properties and shown to be suitable for not only super twisted nematic (STN) but also for thin film transistor (TFT)‐addressed liquid crystals displays. 1. Introduction 2. Fluorination Reactions 2.1 Fluorination of Sulfides and Thiols 2.2 Fluorination of Dithioacetals 2.3 Oxidative Desulfurization‐Fluorination of Dithioester and Orthothioester 2.4 Synthesis of Trifluoromethyl Ethers from Dithiocarbonates 2.5 Oxidative Desulfurization‐Fluorination of Thionesters and Thioncarbonates 2.6 Synthesis of Trifluoromethylamines from Dithiocarbamates 3. Synthesis and Electro‐Optical Properties of Novel Fluorine‐Containing Liquid Crystals 3.1 Synthesis and Electro‐Optical Properties of N‐Trifluoromethylamino‐Substituted Liquid Crystals 3.2 Syntheses and Electro‐Optical Properties of Liquid Crystals having Trifluoromethoxy Polar Functional Group 3.3 Synthesis and Properties of 3‐Substituted Phenyl Trifluoromethyl Ethers 3.4 Synthesis and Electro‐Optical Properties of Liquid Crystals with a vic‐Difluoro‐Olefinic Moiety     

Synthesis and characterization of thermotropic liquid crystalline poly(ester‐imide‐ketone)

A series of poly(ester imide ketone)s derived from N,N′‐hexane‐1,6‐diylbis(trimellitimide), 4,4′‐dihydroxybenzophenone, and p‐hydroxybenzoic acid (PHB) were synthesized by the direct polycondensation method in benzene sulfonyl chloride, dimethylformamide, and pyridine with varied PHB contents. The liquid crystalline behavior and thermal properties of the poly(ester imide ketone)s were characterized by polarized‐light microscopy, wide‐angle X‐ray diffraction, thermogravimetric analysis, differential scanning calorimetry, and temperature‐modulated differential scanning calorimetry (MDSC). The results showed that the synthesized polymers possessed a nematic thermotropic liquid crystalline characteristic and high thermal stability. The liquid crystalline polymers, with a PHB content ranging from 0 to 50 mol %, exhibited multiple phase transitions as evidenced by the MDSC results. A transitional smectic phase from solid state to nematic thermotropic liquid crystalline state was observed, and a transition model is proposed. Under certain conditions, the polymer with 33 mol % PHB content showed two significantly different liquid crystalline textures. This type of liquid crystalline polymer exhibited excellent fiber forming. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1045–1052, 2003     

Copolymer hydrogel microspheres consisting of modified sulfate chondroitin‐co‐poly(N‐isopropylacrylamide)

Modified chondroitin sulfate (π‐CdS) microspheres were synthesized by way of crosslinking‐copolymerization reaction with N‐isopropylacrylamide (NIPAAm), yielding CdS‐co‐PNIPAAm copolymer network. The incorporation of vinyl groups onto the CdS was processed with the use of glycidyl methacrylate (GMA) in an aqueous solution of pH 3.5 under stirring speed of 800 rpm at 50°C. ¹³C NMR and ¹H NMR spectra of CdS treated with the GMA indicated the formation of 3‐methacryloyl‐1‐glyceryl ester of π‐CdS and 3‐methacryloyl‐2‐glyceryl ester of π‐CdS that are the reaction products resultant of an epoxide ring‐opening mechanism via. The synthesis of microspheres was performed via radical reaction of the vinyl groups at the π‐CdS with vinyl groups at the NIPAAm in a water−benzyl alcohol microemulsion. The formation of spherical structures is the result of the polymerization‐crosslinking reaction of the π‐CdS with the NIPAAm monomers at the droplets of water, in view that both reactants have hydrophilic characteristics at the temperature at which the reaction was processed. The pure CdS hydrogel microspheres showed a slightly cracked structure with a lower diameter range while the CdS‐co‐PNIPAAm hydrogel microspheres showed a flat and tight structure with a more regular mass distribution. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Copolymers based on poly(butylene terephthalate) and polycaprolactone‐block‐polydimethylsiloxane‐block‐polycaprolactone

A series of novel thermoplastic elastomers, based on poly(butylene terephthalate) (PBT) and polycaprolactone‐block‐polydimethylsiloxane‐block‐polycaprolactone (PCL‐PDMS‐PCL), with various mass fractions, were synthesized through melt polycondensation. In the synthesis of the poly(ester‐siloxane)s, the PCL blocks served as a compatibilizer for the non‐polar PDMS blocks and the polar comonomers dimethyl terephthalate and 1,4‐butanediol. The introduction of PCL‐PDMS‐PCL soft segments resulted in an improvement of the miscibility of the reaction mixture and therefore in higher molecular weight polymers. The content of hard PBT segments in the polymer chains was varied from 10 to 80 mass%. The degree of crystallinity of the poly(ester‐siloxane)s was determined using differential scanning calorimetry and wide‐angle X‐ray scattering. The introduction of PCL‐PDMS‐PCL soft segments into the polymer main chains reduced the crystallinity of the hard segments and altered related properties such as melting temperature and storage modulus, and also modified the surface properties. The thermal stability of the poly(ester‐siloxane)s was higher than that of the PBT homopolymer. The inclusion of the siloxane prepolymer with terminal PCL into the macromolecular chains increased the molecular weight of the copolymers, the homogeneity of the samples in terms of composition and structure and the thermal stability. It also resulted in mechanical properties which could be tailored. Copyright © 2010 Society of Chemical Industry     

Synthesis and properties of PMR type poly(benzimidazopyrrolone‐imide)s

PMR type poly(benzimidazopyrrolone‐imide) or poly(pyrrolone‐imide) (PPI) matrix resin was synthesized using the diethyl ester of 4,4′‐(hexafluoroisopropylidene)diphthalic acid (6FDE), 3,3′‐diaminobenzidine, para‐phenylenediamine, and monoethyl ester of cis‐5‐norbornene‐endo‐2,3‐dicarboxylic acid (NE) in anhydrous ethyl alcohol with N‐methylpyrrolidone. The homogeneous matrix resin solution (40–50% solid) was stable for a storage period of 2 weeks and showed good adhesion with carbon fibers, which ensured production of prepregs. The chemical and thermal processes in the polycondensation of the monomeric reactant mixture were monitored by Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, scanning electron microscopy, etc. Thermosetting PPI as well as short carbon fiber‐reinforced polymer composites was accomplished at optimal thermal curing conditions. The polymer materials, after postcuring, showed excellent thermal stability, with an initial decomposition temperature > 540°C. Results of MDA experiments indicate that the materials showed > 70–80% retention of the storage modulus at 400°C and glass transition temperatures as high as 440–451°C. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1600–1608, 2001     

Thermally exfoliated graphene oxide reinforced fluorinated pentablock poly(l‐lactide‐co‐ε‐caprolactone) electrospun scaffolds: Insight into antimicrobial activity and biodegradation

Three‐dimensional fluorinated pentablock poly(l ‐lactide‐co‐ε‐caprolactone)‐based scaffolds were successfully produced by the incorporation of thermally exfoliated graphene oxide (TEGO) as an antimicrobial agent with an electrospinning technique. In a ring‐opening polymerization, the fluorinated groups in the middle of polymer backbone were attached with a perfluorinated reactive stabilizer having oxygen‐carrying ability. The fiber diameter and its morphologies were optimized through changes in TEGO amount, voltage, polymer concentration, and solvent type to obtain an ideal scaffold structure. Instead of the widely used graphene oxide synthesized by Hummer's method, TEGO sheets having a low amount of oxygen produced by thermal expansion were integrated into the fiber structure to investigate the effect of the oxygen functional groups of TEGO sheets on the degradation and antimicrobial activity of the scaffolds. There was no antimicrobial activity in TEGO‐reinforced scaffolds in the in vitro tests in contrast to the literature. This study confirmed that a low number of oxygen functional groups on the surface of TEGO restricted the antimicrobial activity of the fabricated composite scaffolds. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43490.     

电化学氟化技术及其应用

电化学氟化(ECF)技术是用镍作阳极,在无水氟化氢中电解制备全氟化合物的一种方法.围绕ECF的原理,介绍了其反应机理.讨论了底物、反应介质、电极电压、电流密度等因素对ECF的影响.在不同电解氟化条件下,探讨了合成的相应氟化产物的稳定性和电化学性能.讨论了多种有机物的ECF的特点及应用.     

Preparation and characterization of unsaturated poly(ester‐imide) based on 1,4‐bis[2′‐trifluoromethyl‐4′‐(4″‐glycolformate)‐trimellitimidophenoxy]benzene

A novel diimidodialcohol monomer, 1,4‐bis[2′‐trifluoromethyl‐4′‐(4″‐glycolformate)‐ trimellitimidophenoxy]benzene (BGTB), was synthesized and characterized. It was reacted with isophthalic acid, maleic anhydride and propylene glycol to produce a novel unsaturated poly(ester‐imide) (BGTB‐UPEI) with imide and trifluoromethyl groups in the polymer backbone. The BGTB‐UPEI resin was diluted with reactive monomer (styrene) to give a low‐viscous poly(ester‐imide)/styrene (BGTB‐UPEI/St) mixed solution, which was then thermally cured to yield thermosetting BGTB‐UPEI/St composite. The effect of processing parameters such as the curing temperature and curing time, reactive monomer concentration and initiator amount on the curing reaction was systematically investigated. Experimental results indicated that the thermally cured BGTB‐UPEI/St composite exhibited much better thermal, mechanical, electrical insulating properties and chemical resistance than the standard unsaturated polyester/polystyrene composite. Copyright © 2006 Society of Chemical Industry     

Synthesis and characterization of novel heat resistance poly(amide‐imide)s from N,N′‐[2,5‐bis(4‐aminobenzylidene) cyclopentanone] bistrimellitimide acid and various aromatic diamines

A new‐type of dicarboxylic acid was synthesized from the reaction of 2,5‐bis(4‐aminobenzylidene)cyclopentanone with trimellitic anhydride in a solution of glacial acetic acid/pyridine (Py) at refluxing temperature. Six novel heat resistance poly(amide‐imide)s (PAIs) with good inherent viscosities were synthesized, from the direct polycondensation reaction of N,N′‐[2,5‐bis(4‐aminobenzylidene)cyclopentanone]bistrimellitimide acid with several aromatic diamines, by two different methods such as direct polycondensation in a medium consisting of N‐methyl‐2‐pyrrolidone (NMP)/triphenyl phosphite (TPP)/calcium chloride (CaCl₂)/pyridine (Py) and direct polycondensation in a p‐toluene sulfonyl chloride (tosyl chloride, TsCl)/pyridine (Py)/N,N‐dimethylformamide (DMF) system. All of the above polymers were fully characterized by ¹H NMR, FTIR, elemental analysis, inherent viscosity, solubility tests, UV‐vis spectroscopy, differential scanning calorimeter (DSC), thermogravimetric analysis (TGA), and derivative of thermaogravimetric (DTG). The resulted poly(amide‐imide)s (PAIs) have showed admirable good inherent viscosities, thermal stability, and solubility. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Organosoluble,low‐dielectric‐constant fluorinated polyimides based on 2,6‐bis(4‐amino‐2‐trifluoromethylphenoxy)naphthalene

A novel fluorinated bis(ether amine) monomer, 2,6‐bis(4‐amino‐2‐trifluoromethylphenoxy) naphthalene, was prepared through the nucleophilic aromatic substitution reaction of 2‐chloro‐5‐nitrobenzotrifluoride and 2,6‐dihydroxynaphthalene in the presence of potassium carbonate, followed by catalytic reduction with hydrazine and Pd/C in ethanol. A series of novel trifluoromethylated polyimides were synthesized from the diamine with various commercially available aromatic tetracarboxylic dianhydrides using a two‐stage process with thermal imidization of poly(amic acid) films. Most of the resulting polyimides were highly soluble in a variety of organic solvents and could afford transparent and tough films via solution casting. These polyimides exhibited moderately high glass transition temperatures (T_gs) of 249–311 °C, high thermal stability and good mechanical properties. Low moisture (0.19–0.85 %), low dielectric constants (2.49–3.59 at 10 kHz), and low color intensity were also observed. For a comparative study, a series of analogous polyimides based on 2,6‐bis(4‐aminophenoxy)naphthalene were also prepared and characterized. Copyright © 2005 Society of Chemical Industry