Effects of the solvent polarity on the atom transfer radical polymerization of methyl methacrylate initiated by 4‐(chloromethyl)phenyltrimethoxysilane

The controllability of the atom transfer radical polymerization of methyl methacrylate in the polar solvent N,N‐dimethylformamide and the nonpolar solvent xylene with 4‐(chloromethyl)phenyltrimethoxysilane as an initiator and with CuCl/2,2′‐bipyridine and CuCl/4,4′‐di(5‐nonyl)‐2,2′‐bipyridine as catalyst systems was studied. Gel permeation chromatography analysis established that in the nonpolar solvent xylene, much better control of the molecular weight and polydispersity of poly(methyl methacrylate) was achieved with the CuCl/4,4′‐di(5‐nonyl)‐2,2′‐bipyridine catalyst system than with the CuCl/2,2′‐bipyridine as catalyst system. In the polar solvent N,N‐dimethylformamide, unlike in xylene, the polymerization was more controllable with the CuCl/2,2′‐bipyridine catalyst system than with the CuCl/4,4′‐di(5‐nonyl)‐2,2′‐bipyridine catalyst system. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2751–2754, 2007     

Effect of chlorine substitution in 4,4′‐diaminodiphenylmethane hardener on shelf life and mechanical properties of epoxies

Curing of N,N,N′,N′‐tetraglycidyldiaminodiphenylmethane with new curing agents like 3,3′‐dichloro‐4,4′‐diaminodiphenylmethane and 2,2′‐dichloro‐4,4′‐diaminodiphenylmethane in comparison with diaminodiphenylmethane and 4,4′‐diaminodiphenylsulphone (DDS) was carried out using dynamic differential scanning calorimetry. The shelf life of various epoxy formulations was evaluated by the residual cure exotherm method. The glass‐transition temperatures of cured epoxy formulations were determined using dynamic mechanical analysis. The mechanical properties such as the tensile strength, tensile modulus, flexural strength, and Izod impact strength were also evaluated and compared. The activation energy, frequency factor, and shelf life of chloro‐substituted hardener formulations were high as compared to those of unsubstituted hardener formulations. The marginal differences in the glass‐transition temperature, tensile strength, tensile modulus, and flexural strength and the small decrement in the Izod impact strength values were interpreted in terms of chlorine substitution. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 3082–3088, 2002; DOI 10.1002/app.2337     

Synthesis of novel bipyridyl ligands and application in preparation of polyketone

In this article, novel 2,2′‐bipyridyl derivatives were synthesized and the excellent bipyridyl ligands were chosen as catalyst to apply in the copolymerization of carbon monoxide (CO) and styrene (ST) to prepare polyketone. 4,4′‐Dicarboxyl‐2,2′‐bipyridine(4,4′‐dcpy) was synthesized by use of synthesized 4,4′‐dimethyl‐2,2′‐bipyridine(4,4′‐dmpy). The products (4,4′‐dmpy and 4,4′‐dcpy) were characterized by melting point, NMR, IR, GC‐MS, and elemental analysis. The effects of different ligands and various reaction conditions incuding the usage of ligand, p‐toluenesulfonic acid, solvent, p‐benzoquinone, the CO pressure, and reaction temperature on catalytic activity of the copolymerization were investigated. The catalytic activity of 4,4′‐dmpy, 4,4′‐dcpy and 2,2′‐bipyridine were compared. The results showed that the addition of the electron‐donating substituent can enhance catalytic activity, with the sequence as follows: 4,4′‐ dimethyl‐2,2′‐bipyridine > 2,2′‐bipyridine > 4, 4′‐carboxy 2,2′‐ bipyridine. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci 000: 000–000, 2012     

Application of microwave irradiation for synthesis of novel optically active poly(amide imides) derived from diacid chloride containing epiclon and L‐isoleucine with aromatic diamines

Epiclon [3a,4,5,7a‐tetrahydro‐7‐methyl‐5‐(tetrahydro‐2,5‐dioxo‐3‐furanyl)‐1,3‐isobenzofurandione] or [5‐(2,5‐dioxotetrahydrofurfuryl)‐3‐methyl‐3‐cyclohexyl‐1,2‐dicarboxylic acid anhydride] (1) was reacted with L ‐isoleucine (2) in acetic acid and the resulting imide acid (3) was obtained in high yield. The diacid chloride (4) was obtained from diacid derivative (3) by reaction with thionyl chloride. The polycondensation reaction of diacid chloride (4) with several aromatic diamines such as 4,4′‐sulfonyldianiline (5a), 4,4′‐diaminodiphenyl methane (5b), 4,4′‐diaminodiphenylether (5c), p‐phenylenediamine (5d), m‐phenylenediamine (5e), 2,4‐diaminotoluene (5f), and 4,4′‐diaminobiphenyl (5g) was developed by using a domestic microwave oven in the presence of a small amount of a polar organic medium such as o‐cresol. The polymerization reactions were also performed in two other different methods: low‐temperature solution polycondensation and reflux conditions. A series of optically active poly(amide imides) with inherent viscosity of 0.12–0.30 dL/g were obtained. All of the above polymers were fully characterized by IR, elemental analyses, and specific rotation techniques. Some structural characterizations and physical properties of these optically active poly(amide imides) are reported. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2218–2229, 2004     

Synthesis and characterization of new soluble poly(ester‐imide)s containing noncoplanar 2,2′‐dimethyl‐4,4′‐biphenylene unit

A new diimide–diacid chloride (3) containing a noncoplanar 2,2′‐dimethyl‐4,4′‐biphenylene unit was synthesized by treating 2,2′‐dimethyl‐4,4′‐diamino‐biphenylene with trimellitic anhydride followed by refluxing with thionyl chloride. Various new poly(ester‐imide)s were prepared from 3 with different bisphenols by solution polycondensation in nitrobenzene using pyridine as hydrogen chloride quencher at 170°C. Inherent viscosities of the poly(ester‐imide)s were found to range between 0.31 and 0.35 dL g^?1. All of the poly(ester‐imide)s, except the one containing pendent adamantyl group 5e, exhibited excellent solubility in the following solvents: N,N‐dimethylformamide, tetrahydrofuran, tetrachloroethane, dimethyl sulfoxide, N,N‐dimethylacetamide, N‐methyl‐2‐pyrrolidinone, m‐cresol, o‐chlorophenol, and chloroform. The polymers showed glass‐transition temperatures between 166 and 226°C. The 10% weight loss temperatures of the poly(ester‐imide)s, measured by TGA, were found to be in the range between 415 and 456°C in nitrogen. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2486–2493, 2004     

Synthesis and characterization of novel polyaspartimides derived from 2,2′‐dimethyl‐4,4′‐bis(4‐maleimidophenoxy)biphenyl and various diamines

A novel bismaleimide, 2,2′‐dimethyl‐4,4′‐bis(4‐maleimidophenoxy)biphenyl, containing noncoplanar 2,2′‐dimethylbiphenylene and flexible ether units in the polymer backbone was synthesized from 2,2′‐dimethyl‐4,4′‐bis(4‐aminophenoxy)biphenyl with maleic anhydride. The bismaleimide was reacted with 11 diamines using m‐cresol as a solvent and glacial acetic acid as a catalyst to produce novel polyaspartimides. Polymers were identified by elemental analysis and infrared spectroscopy, and characterized by solubility test, X‐ray diffraction, and thermal analysis (differential scanning calorimetry and thermogravimetric analysis). The inherent viscosities of the polymers varied from 0.22 to 0.48 dL g⁻¹ in concentration of 1.0 g dL⁻¹ of N,N‐dimethylformamide. All polymers are soluble in N‐methyl‐2‐pyrrolidone, N,N‐dimethylacetamide, N,N‐dimethylformamide, dimethylsulfoxide, pyridine, m‐cresol, and tetrahydrofuran. The polymers, except PASI‐4, had moderate glass transition temperature in the range of 188°–226°C and good thermo‐oxidative stability, losing 10% mass in the range of 375°–426°C in air and 357°–415°C in nitrogen. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 279–286, 1999     

Phosphorus‐containing epoxy resins: Thermal characterization

Three novel aromatic phosphorylated diamines, i.e., bis N,N′‐{3‐[(3‐aminophenyl)methyl phosphinoyl] phenyl} pyromellitamic acid (AP), 4,4′‐oxo bis N,N′‐{3‐[(3‐aminophenyl)methyl phosphinoyl] phenyl}phthalamic acid (AB) and 4,4′‐hexafluoroisopropylidene‐bis N,N′‐{3‐[(3‐aminophenyl)methyl phosphinoyl] phenyl}phthalamic acid (AF) were synthesized and characterized. These amines were prepared by solution condensation reaction of bis(3‐aminophenyl)methyl phosphine oxide (BAP) with 1,2,4,5‐benzenetetracarboxylic acid anhydride (P)/3,3′,4,4′‐benzophenonetetracarboxylic acid dianhydride (B)/4,4′‐(hexafluoroisopropylidene)diphthalic acid anhydride (F), respectively. The structural characterization of amines was done by elemental analysis, DSC, TGA, ¹H‐NMR, ¹³C‐NMR and FTIR. Amine equivalent weight was determined by the acetylation method. Curing of DGEBA in the presence of phosphorylated amines was studied by DSC and curing exotherm was in the temperature range of 195–267°C, whereas with conventional amine 4,4′‐diamino diphenyl sulphone (D) a broad exotherm in temperature range of 180–310°C was observed. Curing of DGEBA with a mixture of phosphorylated amines and D, resulted in a decrease in characteristic curing temperatures. The effect of phosphorus content on the char residue and thermal stability of epoxy resin cured isothermally in the presence of these amines was evaluated in nitrogen atmosphere. Char residue increased significantly with an increase in the phosphorus content of epoxy network. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2235–2242, 2002     

Synthesis and properties of new poly(amide imide)s containing trimellitic rings and hydantoin moieties in the main chain under microwave irradiation

Trimellitic anhydride was reacted with 4,4′‐diaminodiphenyl ether in a mixture of acetic acid and pyridine (3 : 2) at room temperature and was refluxed at 90–100°C, and N,N′‐(4,4′‐diphenylether) bistrimellitimide (3) was obtained in a quantitative yield. 3 was converted into N,N′‐(4,4′‐diphenylether) bistrimellitimide diacid chloride (4) by a reaction with thionyl chloride. Then, six new poly(amide imide)s were synthesized under microwave irradiation with a domestic microwave oven through the polycondensation reactions of 4 with six different derivatives of 5,5‐disubstituted hydantoin in the presence of a small amount of a polar organic medium such as o‐cresol. The polycondensation proceeded rapidly and was completed within 7–10 min, producing a series of new poly(amide imide)s in high yields with inherent viscosities of 0.27–0.66 dL/g. The resulting poly(amide imide)s were characterized by elemental analysis, viscosity measurements, differential scanning calorimetry, thermogravimetric analysis, derivative thermogravimetry, solubility testing, and Fourier transform infrared spectroscopy. All the polymers were soluble at room temperature in polar solvents such as N,N‐dimethylacetamide, N,N‐dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, and N‐methyl‐2‐pyrrolidone. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3447–3453, 2004     

Resistive switching characteristics of polyimides derived from 2,2′‐aryl substituents tetracarboxylic dianhydrides

2,2′‐Position aryl‐substituted tetracarboxylic dianhydrides including 2,2′‐bis(biphenyl)‐4,4′,5,5′‐biphenyl tetracarboxylic dianhydride and 2,2′‐bis[4‐(naphthalen‐1‐yl)phenyl)]‐4,4′,5,5′‐biphenyl tetracarboxylic dianhydride were synthesized. A new series of aromatic polyimides (PIs) were synthesized via a two‐step procedure from 3,3′,4,4′‐biphenyl tetracarboxylic dianhydride and the newly synthesized tetracarboxylic dianhydrides monomers reacting with 2,2′‐bis[4′‐(3″,4″,5″‐trifluorophenyl)phenyl]‐4,4′‐biphenyl diamine. The resulting polymers exhibited excellent organosolubility and thermal properties associated with T_g at 264 °C and high initial thermal decomposition temperatures (T_5%) exceeding 500 °C in argon. Moreover, the fabricated sandwich structured memory devices of Al/PI‐a/ITO was determined to present a flash‐type memory behaviour, while Al/PI‐b/ITO and Al/PI‐c/ITO exhibited write‐once read‐many‐times memory capability with different threshold voltages. In addition, Al/polymer/ITO devices showed high stability under a constant stress or continuous read pulse voltage of ? 1.0 V. Copyright © 2011 Society of Chemical Industry     

Synthesis and properties of new aromatic polyimides based on 2,2′‐dibromo‐4,4′,5,5′‐benzophenone tetracarboxylic dianhydride

New polyimides with enhanced thermal stability and high solubility were synthesized in common organic solvents from a new dianhydride, 2,2′‐dibromo‐4,4′,5,5′‐benzophenone tetracarboxylic dianhydride (DBBTDA). DBBTDA was used as monomer to synthesize polyimides by using various aromatic diamines. The polymers were characterized by IR and NMR spectroscopy and elemental analysis. These polyimides had good inherent viscosities in N‐methyl‐2‐pyrrolidinone (NMP) and also high solubility and excellent thermo‐oxidative stability, with 5 % weight loss in the range 433 to 597 °C. Copyright © 2004 Society of Chemical Industry     

Magnetic heat resistant poly(amide–imide) nanocomposite derived from bisphenol A: Synthesis and properties

New magnetic and heat resistant poly(amide–imide) nanocomposite (PAIN) was prepared from Fe₃O₄ nanoparticles and poly(amide‐imide) (PAI) in a solution of N‐methyl‐2‐pyrrolidone. New PAI derived from bisphenol A containing aryl sulfone and ether moiety was synthesized from 2,2′‐(4,4′‐(4,4′‐(propane‐2,2‐diyl)bis(4,1‐phenylene))bis(oxy)bis(4,1‐phenylene))bis(1,3‐dioxoisoindoline‐5‐carboxylic acid) 5 as a new diacid and 4,4′‐diaminodiphenyl sulfone by direct polycondensation reaction. Fe₃O₄ nanoparticles were prepared by coprecipitation method and characterized using Fourier transform infrared, X‐ray diffraction, scanning electron microscopy (SEM), and vibrating samples magnetometer (VSM). The new poly(amide‐imide)/Fe₃O₄ nanocomposite was characterized using SEM, FTIR, and VSM. The effect of Fe₃O₄ nanoparticles on the thermal properties of PAI was studied using thermogravimetric analysis and differential scanning calorimeter. POLYM. COMPOS., 34:1682–1689, 2013. © 2013 Society of Plastics Engineers     

Cure kinetics of epoxy resin and aromatic diamines

The kinetics of curing reaction of a diglycidyl ether of a bisphenol‐A based epoxy (DGEBA) with 4,4′‐diaminostillbene (DAS) and 4,4′‐diaminoazobenzene (DAAB) as curing agents are studied by differential scanning calorimetery (DSC) using the isothermal technique. The experimental data show that the cure reaction is autocatalytic in nature, and all kinetic parameters of the curing reaction are determined using a semiempirical equation. The reaction of DGEBA with DAS is faster than that with DAAB under the same conditions and the activation energies of both systems are higher than those reported for other aromatic diamines. With increasing isothermal temperature and concentration of curing agents the rate constants are increased by the increasing of probability collisions between epoxide and primary amine groups while the activation energies remain constant. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1049–1056, 2004     

Organosoluble polyimides derived from asymmetric 2‐substituted‐and 2,2′,6‐trisubstituted‐4,4′‐oxydianilines

We report a new method for the preparation of asymmetric diamines using 4,4′‐oxydianiline (4,4′‐ODA) as the starting material. By controlling the equivalents of bromination agent, N‐bromosuccinimide, we were able to attach bromide and phenyl substituents at the 2‐ or 2,2′,6‐positions of 4,4′‐ODA. Thus, four new asymmetric aromatic diamines, 2‐bromo‐4,4′‐oxydianiline (6), 2,2′,6‐tribromo‐4,4′‐oxydianiline (7), 2‐phenyl‐4,4′‐oxydianiline (8) and 2,2′,6‐triphenyl‐4,4′‐oxydianiline (9), were synthesized by this method. Their structural asymmetry was confirmed using ¹H NMR spectroscopy. Asymmetric polyimides (PI10–PI13) were prepared from these diamines and three different dianhydrides (pyromellitic dianhydride (PMDA), 3,3′,4,4′‐biphenyltetracarboxylic dianhydride and 2,2‐bis(3,4‐dicarboxyphenyl)hexafluoropropane dianhydride) in refluxing m‐cresol. The formed polyimides, except PI10a derived from 6 and PMDA, were all soluble in m‐cresol without premature precipitation during polymerization. These polyimides with inherent viscosity of 0.41–0.96 dL g^?1, measured at a concentration of 0.5 g dL^?1 in N‐methyl‐2‐pyrrolidone at 30 °C, can form tough and flexible films. Because of the structural asymmetry, they also exhibited enhanced solubility in organic solvents. Especially, polyimides PI11a and PI13a derived from 7 and 9 with rigid PMDA were soluble in various organic solvents at room temperature. The structural asymmetry of the prepared polyimides was also evidenced from ¹H NMR spectroscopy. In the ¹H NMR spectrum of PI11a, the protons of pyromellitic moiety appeared in an area ratio of 1:2:1 at three different chemical shifts, which were assigned to head‐to‐head, head‐to‐tail and tail‐to‐tail configurations, respectively. These polyimides also exhibited good thermal stability. Their glass transition temperatures ranged from 297 to 344 °C measured using thermal mechanical analysis. © 2013 Society of Chemical Industry     

Synthesis and characterization of new optically active poly(amide‐imide‐urethane) thermoplastic elastomers,derived from 4,4′‐(hexafluoroisopropylidene)‐N,N′‐bis(phthaloyl‐L‐leucine‐p‐aminobenzoic acid) and PEG‐MDI

A new class of optically active poly(amide‐imide‐urethane) was synthesized via two‐step reactions. In the first step, 4,4′‐methylene‐bis(4‐phenylisocyanate) (MDI) reacts with several poly(ethylene glycols) (PEGs) such as PEG‐400, PEG‐600, PEG‐2000, PEG‐4000, and PEG‐6000 to produce the soft segment parts. On the other hand, 4,4′‐(hexafluoroisopropylidene)‐N,N′‐bis(phthaloyl‐L ‐leucine‐p‐amidobenzoic acid) (2) was prepared from the reaction of 4,4′‐(hexafluoroisopropylidene)‐N,N′‐bis(phthaloyl‐L ‐leucine) diacid chloride with p‐aminobenzoic acid to produce hard segment part. The chain extension of the above soft segment with the amide‐imide 2 is the second step to give a homologue series of poly(amide‐imide‐urethanes). The resulting polymers with moderate inherent viscosity of 0.29–1.38 dL/g are optically active and thermally stable. All of the above polymers were fully characterized by IR spectroscopy, elemental analyses, and specific rotation. Some structural characterization and physical properties of this new optically active poly(amide‐imide‐urethanes) are reported. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2288–2294, 2004     

Synthesis of new optically active poly(amide‐imide)s containing EPICLON and L‐phenylalanine in the main chain by microwave irradiation and classical heating

EPICLON [3a,4,5,7a‐Tetrahydro‐7‐methyl‐5‐(tetrahydro‐2,5‐dioxo‐3‐furanyl)‐1,3‐isobenzofurandione] or [5‐(2,5‐dioxotetrahydrofurfuryl)‐3‐methyl‐3‐cyclohexyl‐1,2‐dicarboxylic acid anhydride] ( 1 ) was reacted with L ‐phenylalanine ( 2 ) in acetic acid, and the resulting amic acid was refluxed under a Dean‐Stark system with benzene, which produced diacid ( 3 ) in high yield. Compound ( 3 ) was converted to the diacid chloride ( 4 ) by reaction with oxalyl chloride in dry carbon tetrachloride. The polycondensation reaction of this diacid chloride ( 4 ) with several aromatic diamines such as 4,4′‐sulfonyldianiline ( 5a ), 4,4′‐diaminodiphenylmethane ( 5b ), 4,4′‐diaminodiphenylether ( 5c ), 1,4‐phenylenediamine ( 5d ), 1,3‐phenylenediamine ( 5e ), 2,4‐diaminotoluene ( 5f ), and 1,5‐diaminonaphthalene ( 5g ) was developed by using a domestic microwave oven in the presence of a small amount of a polar organic medium such as N‐methylpyrrolidone ( NMP ). The polymerization reactions were also performed under two different classical heating methods: low temperature solution polycondensation in the presence of trimethylsilyl chloride, and high temperature polymerization. A series of optically active poly(amide‐imide)s with moderate yield and inherent viscosity of 0.14–0.22 dL/g were obtained. All of the above polymers were fully characterized by IR, elemental analyses, and specific rotation. Some structural characterization and physical properties of this optically active poly(amide‐imide)s are reported. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3281–3291, 2004     

Synthesis and characterization of organosoluble and transparent polyimides derived from trans‐1,2‐bis(3,4‐dicarboxyphenoxy)cyclohexane dianhydride

A novel dianhydride, trans‐1,2‐bis(3,4‐dicarboxyphenoxy)cyclohexane dianhydride (1,2‐CHDPA), was prepared through aromatic nucleophilic substitution reaction of 4‐nitrophthalonitrile with trans‐cyclohexane‐1,2‐diol followed by hydrolysis and dehydration. A series of polyimides (PIs) were synthesized from one‐step polycondensation of 1,2‐CHDPA with several aromatic diamines, such as 2,2′‐bis(trifluoromethyl)biphenyl‐4,4′‐diamine (TFDB), bis(4‐amino‐2‐trifluoromethylphenyl)ether (TFODA), 4,4′‐diaminodiphenyl ether (ODA), 1,4‐bis(4‐aminophenoxy)benzene (TPEQ), 4,4′‐(1,3‐phenylenedioxy)dianiline (TPER), 2,2′‐bis[4‐(3‐aminodiphenoxy)phenyl]sulfone (m‐BAPS), and 2,2′‐bis[4‐(4‐amino‐2‐trifluoromethylphenoxy)phenyl]sulfone (6F‐BAPS). The glass transition temperatures (T_gs) of the polymers were higher than 198°C, and the 5% weight loss temperatures (T_d5%s) were in the range of 424–445°C in nitrogen and 415–430°C in air, respectively. All the PIs were endowed with high solubility in common organic solvents and could be cast into tough and flexible films, which exhibited good mechanical properties with tensile strengths of 76–105 MPa, elongations at break of 4.7–7.6%, and tensile moduli of 1.9–2.6 GPa. In particular, the PI films showed excellent optical transparency in the visible region with the cut‐off wavelengths of 369–375 nm owing to the introduction of trans‐1,2‐cyclohexane moiety into the main chain. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42317.     

Synthesis and properties of aromatic polyimide,poly(benzoxazole imide), and poly(benzoxazole amide imide)

Two series of heterocyclic aromatic polymers were synthesized from 4,4′‐(4,4′‐isopropylidenediphenoxy)bis(phthaltic anhydride) and 2,2′‐bis(3,4‐dicarboxyphenyl)hexafluoropropane dianhydride by two‐step method. The inherent viscosities were in the range of 24–45 cm³/g. The effects of the rigid benzoxazole group in the backbone of copolymer on the thermal, mechanical, and physical properties were investigated. These polymers exhibit good thermal stability. The temperatures of 5% weight loss (T₅) of these polymers are in the range of 403–530°C in air and 425–539°C in nitrogen. The chard yields of these polymers are in the range of 15–24% in air and 54–61% in nitrogen. These polymers also have high glass‐transition temperatures and a low coefficient of thermal expansion and good mechanical properties. The poly(benzoxazol imide) has a higher tensile strength and modulus than those of neat polyimide. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Thermally stable and organosoluble cardo binaphthylene based poly(amide imide)s and poly(ester imide)s

A new imide‐containing dicarboxylic acid based on a twisted binaphthylene unit, 2,2′‐bis(N‐trimellitoyl)‐1,1′‐binaphthyl (1), was synthesized from 1,1′‐binaphthyl‐2,2′‐diamine and trimellitic anhydride in glacial acetic acid. The structure of compound 1 was fully characterized with spectroscopic methods and elemental analysis. Series of thermally stable and organosoluble poly(amide imide)s (4a–4d) and poly(ester imide)s (5a–5d) with similar backbones were prepared by the triphenyl phosphite and diphenylchlorophosphate activated direct polycondensation of diimide dicarboxylic acid 1 with various aromatic diamines and diols, respectively. With due attention to the structural similarity of the resulting poly(amide imide)s and poly(ester imide)s, most of the differences between these two block copolyimides could be easily attributed to the presence of alternate amide or ester linkages accompanied by imide groups in the polymer backbone. The ultraviolet maximum wavelength values of the yellowish polymers were determined from their ultraviolet spectra. The crystallinity of these copolyimides was estimated by means of wide‐angle X‐ray diffraction, and the resultant polymers exhibited a nearly amorphous nature, except for the polymers derived from benzidine and 4,4′‐binaphthol. The poly(amide imide)s exhibited excellent solubility in a variety of highly polar aprotic solvents, whereas the poly(ester imide)s showed good solubility in less polar solvents. According to differential scanning calorimetry analyses, polymers 4a–4d and 5a–5d had glass‐transition temperatures between 331 and 357°C and between 318 and 342°C, respectively. The thermal behaviors of the obtained polymers were characterized by thermogravimetric analysis, and the 10% weight loss temperatures of the poly(amide imide)s and poly(ester imide)s were between 579 and 604°C and between 566 and 577°C in nitrogen, respectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3203–3211, 2006     

Synthesis and properties of organosoluble polyimides derived from 2,2′‐dibromo‐ and 2,2′,6,6′‐tetrabromo‐4,4′‐oxydianilines

Two new aromatic diamines, 2,2′‐dibromo‐4,4′‐oxydianiline (DB‐ODA 4 ) and 2,2′,6,6′‐tetrabromo‐4,4′‐oxydianiline (TB‐ODA 5 ), have been synthesized by oxidation, bromination, and reduction of 4,4′‐oxydianiline (4,4′‐ODA). Novel polyimides 6a–f and 7a–f were prepared by reacting DB‐ODA ( 4 ) and TB‐ODA ( 5 ) with several dianhydrides by one‐step method, respectively. The inherent viscosities of these polyimides ranged from 0.31 to 0.99 dL/g (0.5 g/dL, in NMP at 30°C). These polyimides showed enhanced solubilities compared to those derived from 4,4′‐oxydianiline and corresponding dianhydrides. Especially, polyimides 7a , derived from rigid PMDA and TB‐ODA ( 5 ) can also be soluble in THF, DMF, DMAc, DMSO, and NMP. These polyimides also exhibited good thermal stability. Their glass transition temperatures measured by thermal mechanical analysis (TMA) ranged from 251 to 328°C. When the same dianhydrides were used, polyimides 7 containing four bromide substituents had higher glass transition temperatures than polyimides 6 containing two bromide substituents. The effects of incorporating more polarizable bromides on the refractive indices of polyimides were also investigated. The average refractive indices (n_av) measured at 633 nm were from 1.6088 to 1.7072, and the in‐plane/out‐of‐plane birefringences (Δn) were from 0.0098 to 0.0445. It was found that the refractive indices are slightly higher when polyimides contain more bromides. However, this effect is not very obvious. It might be due to loose chain packing resulted from bromide substituents at the 2,2′ and 2,2′,6,6′ positions of the oxydiphenylene moieties. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Continuous‐Flow C?H Borylation of Arene Derivatives

A new continuous‐flow system for C H borylation has been developed. An insoluble catalyst prepared from chloro(1,5‐cyclooctadien)iridium(I) dimer and 2,2′‐bipyridine‐4,4′‐dicarboxylic acid in the presence of bis(pinacolato)diboron exhibited high reactivity under continuous‐flow processing without the loss of expensive iridium metal.