A new triphenylamine-containing diamine monomer, 4,4′-diamino-3′′,4′′-dimethyltriphenylamine (DADT), was successfully synthesized by the cesium fluoride-mediated condensation of 3,4dimethylaniline with 4-fluoronitrobenzene, followed by reduction. The monomer was reacted with various aromatic dicarboxylic acids and tetracarboxylic dianhydrides to produce a series of novel polyamides and polyimides, respectively. A new triphenylamine-containing dicarboxylic acid monomer, 4,4′-trimellitimido-3′′,4′′-dimethyltriphenylamine (TDT), was successfully synthesized by refluxing the diamine, DADT, with trimellitic anhydride in glacial acetic anhydride. A series of new poly(amide-imide)s were prepared from TDT with various diamines by the direct polycondensation. The polymers were obtained in quantitative yields with inherent viscosities of 0.61-2.28 dL g -1 . Most of the polymers dissolved in N-methyl-2pyrrolidinone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, pyridine, and cyclohexanone. These polymers, especially poly(amide-imide)s, showed high glass transition temperatures between 254 and 326 °C. These polymers were fairly stable up to a temperature around or above 400 °C and lost 10% weight in the range of 430-566 and 462-574 °C in nitrogen and air, respectively. These tough and flexible polymer films had a tensile strength of 82-145 MPa, an elongation at break of 5-11%, and a tensile modulus of 1.7-3.3 GPa. The UV-vis absorption spectra revealed that most of the polymers had absorption maxima around 303 nm. Cyclic voltammograms of the polyamides, polyimides, and poly-(amide-imide)s showed an oxidation wave with a peak around 0.9, 1.1, and 1.3 V, respectively.
Two new bis(ether anhydride)s, 2,2‘-dimethyl-4,4‘-bis[4-(3,4-dicarboxyphenoxy)]biphenyl dianhydride (4A) and bis[4-(3,4-dicarboxy phenoxy)phenyl]diphenylmethane dianhydride (4B), were prepared in three steps starting from nitrodisplacement of 4-nitrophthalonitrile with 2,2‘-dimethylbiphenyl-4,4‘-diol and bis(4-hydroxyphenyl)diphenylmethane, respectively, followed by alkaline hydrolysis of the intermediate bis(ether dinitrile)s and subsequent dehydration of the resulting bis(ether diacid)s. A series of new highly organosoluble poly(ether imide)s were prepared from the bis(ether anhydride)s and various diamines by conventional two-stage synthesis. The resulting poly(ether imide)s had inherent viscosities in the range of 0.55−0.81 dL·g-1. GPC measurement revealed that the polymers exhibited number-average molecular weight and weight-average molecular weight up to 45 000 and 82 000, respectively. All the polymers showed typical amorphous diffraction patterns. Almost all the poly(ether imide)s showed excellent solubility and readily dissolved in various solvents such as N-methyl-2-pyrrolidinone, N,N-dimethylacetamide (DMAc), N,N-dimethylformamide, pyridine, cyclohexanone, tetrahydrofuran, and chloroform. These polymers had glass transition temperatures in the range of 224−256 °C. Thermogravimetric analysis showed that all polymers were stable, with 10% weight loss recorded above 489 °C in nitrogen. The isothermal gravimetric analysis results demonstrated that these poly(ether imide)s showed weight losses of 7.0−10.5% after isothermal aging at 350 °C in static air for 20 h. These tough and flexible polymer films could be easily obtained by solution cast from the DMAc solution. These polymer films had tensile strength of 84−116 MPa and tensile modulus of 1.9−2.7 GPa.
A new diimide‐dicarboxylic acid, 2,2′‐dimethyl‐4,4′‐bis(4‐trimellitimidophenoxy)biphenyl (DBTPB), containing a noncoplanar 2,2′‐dimethyl‐4,4′‐biphenylene unit was synthesized by the condensation reaction of 2,2′‐dimethyl‐4,4′‐bis(4‐minophenoxy)biphenyl (DBAPB) with trimellitic anhydride in glacial acetic acid. A series of new polyamide‐imides were prepared by direct polycondensation of DBAPB and various aromatic diamines in N‐methyl‐2‐pyrrolidinone (NMP), using triphenyl phosphite and pyridine as condensing agents. The polymers were produced with high yield and moderate to high inherent viscosities of 0.86–1.33 dL · g−1. Wide‐angle X‐ray diffractograms revealed that the polymers were amorphous. Most of the polymers exhibited good solubility and could be readily dissolved in various solvents such as NMP, N,N‐dimethylacetamide (DMAc), N,N‐dimethylformamide (DMF), dimethyl sulfoxide, pyridine, cyclohexanone, and tetrahydrofuran. These polyamide‐imides had glass‐transition temperatures between 224–302 °C and 10% weight loss temperatures in the range of 501–563 °C in nitrogen atmosphere. The tough polymer films, obtained by casting from DMAc solution, had a tensile strength range of 93–115 MPa and a tensile modulus range of 2.0–2.3 GPa. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 63–70, 2001
A dicarboxylic acid monomer, 5-phthalimidoisophthalic acid, containing a phthalimide pendent group was prepared by the condensation of 5-aminoisophthalic acid and phthalic anhydride in glacial acetic anhydride. The monomer was reacted with various aromatic diamines to produce polyamides using triphenyl phosphite and pyridine as condensing agents. These polyamides were produced with inherent viscosities of 0.64 -1.14 dL ⅐ g Ϫ1 . All the polymers, characterized by wide-angle X-ray diffraction, revealed an amorphous nature resulting from the presence of the bulky pendent group. These polyamides exhibited excellent solubility in a variety of solvents such as Nmethyl-2-pyrrolidinone, N,N-dimethylacetamide (DMAc), N,N-dimethylformamide, dimethyl sulfoxide, pyridine, and cyclohexanone. These polyamides showed glass-transition temperatures (T g 's) between 247 and 273°C (by DSC) and 248 and 337°C (by a dynamic mechanical analyzer). The thermogravimetric analytic measurement revealed the decomposition temperature at 10% weight-loss temperatures (Td 10 ) ranging from 442 to 530°C in nitrogen. The polyamides containing phthalimide groups exhibited higher T g and Td 10 values than those having no phthalimide groups. Transparent, tough, and flexible films of these polyamides could be cast from the DMAc solutions. These casting films had tensile strengths ranging from 81 to 126 MPa, elongations at break ranging from 7 to 13%, and tensile moduli ranging from 2.0 to 2.9 GPa.
A new bulky pendent bis(ether anhydride), 1,1‐bis[4‐(4‐dicarboxyphenoxy)phenyl]‐4‐phenylcyclohexane dianhydride, was prepared in three steps, starting from the nitrodisplacement of 1,1‐bis(4‐hydroxyphenyl)‐4‐phenylcyclohexane with 4‐nitrophthalonitrile to form bis(ether dinitrile), followed by alkaline hydrolysis of the bis(ether dinitrile) and subsequent dehydration of the resulting bis(ether diacid). A series of new poly(ether imide)s were prepared from the bis(ether anhydride) with various diamines by a conventional two‐stage synthesis including polyaddition and subsequent chemical cyclodehydration. The resulting poly(ether imide)s had inherent viscosities of 0.50–0.73 dL g−1. The gel permeation chromatography measurements revealed that the polymers had number‐average and weight‐average molecular weights of up to 57,000 and 130,000, respectively. All the polymers showed typical amorphous diffraction patterns. All of the poly(ether imide)s showed excellent solubility in comparison with the other polyimides derived from adamantane, norbornane, cyclododecane, and methanohexahydroindane and were readily dissolved in various solvents such as N‐methyl‐2‐pyrrolidinone, N,N‐dimethylacetamide (DMAc), N,N‐dimethylformamide, pyridine, cyclohexanone, tetrahydrofuran, and even chloroform. These polymers had glass‐transition temperatures of 226–255 °C. Most of the polymers could be dissolved in chloroform in as high as a 30 wt % concentration. Thermogravimetric analysis showed that all polymers were stable up to 450 °C, with 10% weight losses recorded from 458 to 497 °C in nitrogen. These transparent, tough, and flexible polymer films could be obtained by solution casting from DMAc solutions. These polymer films had tensile strengths of 79–103 MPa and tensile moduli of 1.5–2.1 GPa. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2066–2074, 2002
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