Synthesis and characterization of N-phenylated aromatic polyamides from N-silylated dianilino compounds and aromatic diacid chlorides

N-Phenylated aromatic polyamides of high molecular weights were synthesized by the hightemperature solution polycondensation of N,N′ -di(trimethylsilyl)-substituted dianilino compounds derived from p-dianilinobenzene, bis(4-anllinophenyl) ether, and α,α′-dianilino-p-xylene, with isophthaloyl and terephthaloyl chloride. Almost all of the N-phenylated polyamides were amorphous, and soluble in a variety of organic solvents including dimethylformamide, m-cresol, and chloroform. Transparent and flexible films of these polymers could be cast from the dimethylformamide solutions. Four wholly aromatic polyamides had glass transition temperatures in the range of 195–255°C, and began to lose weight around 400°C in air.     

Preparation and properties of fluorine-containing aromatic polyamides from tetrafluorophthaloyl chlorides and aromatic diamines

New fluorine-containing aromatic polyamides with inherent viscosities of 0.4–1.8 dL/g were prepared by the low temperature solution polycondensation of tetrafluoroisophthaloyl and tetrafluoroterephthaloyl chlorides with N,N′-bis(trimethylsilyl)-substituted aromatic diamines. The aromatic polyperfluoroisophthalamides were amorphous polymers with glass transition temperatures around 280°C, whereas the polyperfluoroterephthalamides were crystalline. Most of these aromatic polyamides were soluble in organic solvents, and began to decompose around 330°C in air or nitrogen atmosphere.     

Preparation and properties of N-phenylated aromatic polyamide-esters from anilinophenols and aromatic diacid chlorides

N-Phenylated aromatic polyamide-esters with high molecular weights were synthesized by the high-temperature solution polycondensation in nitrobenzene at 200°C from combinations of m- and p-anilinophenol and isophthaloyl and terephthaloyl chloride. Reaction variables such as monomer concentration, solvent, temperature, and time were studied to optimize the reaction conditions for the preparation of high molecular weight polymers. Some of the N-phenylated aromatic polyamide-esters have glass transition temperatures around 190°C and good solubility in chlorinated and amide solvents. These polymers gave transparent flexible films by solution-casting. Copolymers from p-anilinophenol and the two diacid chlorides were also synthesized and characterized.     

Spectrophotometric determination of yttrium in aluminium base alloys with 1-[(5-Methyl-2-pyridyl)azo]-2-naphthol

Summary A highly sensitive and selective Spectrophotometric method has been developed for the determination of yttrium in aluminium base alloys. The method is based on the red water-insoluble complex formed when yttrium and 1-[(5-methyl-2-pyridyl)azo]-2-naphthol (5-Me--PAN) react in a pH 9.5–11.2 solution. This complex could be extracted into ether (absorption maximum, 530 nm). Beer's law is obeyed up to 1 p. p. m. of yttrium and the molar absorptivity is 6.4 · 10⁴ l · mole^–1 · cm^–1 at 530 nm.

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Zusammenfassung Eine hochempfindliche und selektive spektrophotometrische Methode zur Bestimmung von Yttrium in Aluminiumlegierungen wurde ausgearbeitet. Sie beruht auf der Bildung der roten, wasserlöslichen Komplexverbindung des Yttriums mit 1-[(5-Methyl-2-pyridyl)azo]-2-naphthol(5-Me--PAN) bei pH 9,5–11,2. Diese Verbindung läßt sich mit Äther extrahieren und hat ein Absorptionsmaximum bei 530 nm. Das Beersche Gesetz ist bis zu 1 ppm Yttrium erfüllt. Die molare Extinktion beträgt 6,4 · 10⁴ 1 · Mol^–1 cm^–1 bei 530 nm.

     

Synthesis of perfluorochemicals for use as blood substitutes,Part I. Electrochemical fluorination of N-methyldecahydroquinoline and N-methyldecahydroisoquinoline

Electrochemical fluorination of N-methyldecahydroquinoline afforded mainly a mixture of $\text{cis}$ and $\text{trans}$ N-(F-methyl)-F-decahydroquinoline, their rearranged isomers and F-propyl-F-cyclohexane arising from the cleavage at carbon-nitrogen bonds, in a ratio of approximately 2:4:6:3. N-Methyldecahydroisoquinoline was also fluorinated electrochemically to give a mixture of $\text{cis}$ and $\text{trans}$ N-(F-methyl)-F-decahydroisoquinoline, their rearranged isomers and 1-(F-ethyl)-2-(F-methyl)-F-cyclohexane in a ratio of approximately 4:4:6:1. No correlation was found between the $\text{cis}$ and $\text{trans}$ ratio of starting materials and that of the corresponding perfluorinated amines. Fluorination of N-methyl-1,2,3,4-tetrahydroquinoline gave much lower yields.     

Preparation and properties of aromatic polyamides from 2,2′-bis(p-aminophenoxy) biphenyl or 2,2′-bis(p-aminophenoxy)-1,1′-binaphthyl and aromatic dicarboxylic acids

New aromatic diamines having kink and crank structures, 2,2′-bis(p-aminophenoxy)biphenyl and 2,2′-bis(p-aminophenoxy)-1,1′-binaphthyl, were synthesized by the reaction of p-fluoronitrobenzene with biphenyl-2,2′-diol and 2,2′-dihydroxy-1,1′-binaphthyl, respectively, followed by catalytic reduction. Biphenyl-2,2′-diyl- and 1,1′-binaphthyl-2,2′-diyl-containing aromatic polyamides having inherent viscosities of 0.44–1.18 and 0.26–0.88 dL/g, respectively, were obtained either by the direct polycondensation or low-temperature solution polycondensation of the diamines with aromatic dicarboxylic acids (or diacid chlorides). These polymers were readily soluble in a variety of organic solvents including N,N-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), dimethyl sulfoxide, m-cresol, and pyridine. Transparent, pale yellow, and flexible films of these polymers could be cast from the DMAc or NMP solutions. These aromatic polyamides containing biphenyl and binaphthyl units had glass transition temperatures in the range of 215–255 and 266–303°C, respectively. They began to lose weight at ca. 380°C, with 10% weight loss being recorded at about 470°C in air. © 1993 John Wiley & Sons, Inc.     

Preparation and properties of aromatic polyimides from 2,2′-bis(p-aminophenoxy)biphenyl or 2,2′-bis)p-aminophenoxy)-1,1′-binaphthyl and aromatic tetracarboxylic dianhydrides

New aromatic polyimides containing a biphenyl-2,2′-diyl or 1,1′-binaphthyl-2,2′-diyl unit were prepared by a conventional two-step method starting from 2,2′-bis(p-aminophenoxy) biphenyl or 2,2′-bis(p-aminophenoxy)-1,1′-binaphthyl and aromatic tetracarboxylic dianhydrides. The polyimides having inherent viscosities of 0.69–0.99 and 0.51–0.59 dL/g, respectively, were obtained. Some of these polymers were readily soluble in a variety of organic solvents including N,N-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), dimethyl sulfoxide, and pyridine. Transparent, flexible, and pale yellow to brown films of these polymers could be cast from the DMAc or NMP polyamic acid solutions. These aromatic polyimides containing biphenyl and binaphthyl units had glass transition temperatures in the range of 200–235 and 286–358°C, respectively. They began to lose weight around 380°C, with 10% weight loss being recorded at about 470°C in air. © 1993 John Wiley & Sons, Inc.     

Preparation and properties of new random and block copolyamides derived from 1,3-bis(3-aminopropyl)tetramethyldisiloxane,aromatic diamines,and isophthaloyl chloride

Random and block disiloxane-containing copolyamides were prepared through one- and two-step procedures, respectively, by the low temperature solution polycondensation in chloroform containing triethylamine hydrochloride starting from 1,3-bis(3-aminopropyl)tetramethyldisiloxane, an aromatic diamine [3,4'-diaminodiphenyl ether (ODA) or m-phenylenediamine], and isophthaloyl chloride. The random copolyamides exhibited composition-dependent single glass transition temperature (T_g), and gave transparent and tough films by solution casting or hot pressing. The ODA-based block copolyamides had two T_g's, and the solvent-cast transparent films exhibited microphase separated morphology. The block copolymers gave better quality films than the single-phase random copolymers. © 1992 John Wiley & Sons, Inc.     

Separation of proteins by hydrophobic interaction chromatography at low salt concentration

We investigated protein separation by hydrophobic interaction chromatography (HIC) at low salt concentration on the supports of various hydrophobicities. Hydrophobic proteins could be successfully separated with more than 90% recovery by gradient elution of ammonium sulfate from 0.3-0.5 M to 0 in 50 mM phosphate buffer (pH 6.8) by using supports whose hydrophobicities were properly adjusted individually for each protein. Satisfactory results were also obtained by isocratic elution without ammonium sulfate and gradient elution of ethanol from 0 to 10%. HIC at low salt concentration was compatible with other modes of liquid chromatography like ion-exchange chromatography. On the other hand, it was not successful to separate hydrophilic proteins at low salt concentration. Recoveries of hydrophilic proteins decreased before they were retained enough as support hydrophobicity increased. Therefore, it is inevitable to use a higher concentration of salt, e.g., 1-2 M ammonium sulfate, on hydrophilic or moderately hydrophobic support in order to retain hydrophilic proteins without decrease in recovery.     

Synthesis of wholly aromatic polysulfonamides from aromatic disulfonyl chlorides and aromatic diamines

Wholly aromatic polysulfonamides of high molecular weight were prepared by the solution poly-condensation of aromatic disulfonyl chlorides with aromatic diamines in tetramethylene sulfone and substituted pyridines as the acid acceptor. Polysulfonamides with inherent viscosities as high as 1.2 were readily obtained by initiating polycondensation at a temperature of 5–10°C to control the side reactions. The polycondensation was fairly fast and was completed in 10 min at 60°C. All the aromatic polysulfonamides dissolved in a wide range of solvents, including acetone and tetrahydrofuran. These polymers were less thermally stable than the corresponding aromatic polyamides.