Aromatic azomethine polymers and fibers

Morgan, Paul W.; Kwolek, Stephanie L.; Pletcher, Terry C.

doi:10.1021/ma00170a006

Cited by 223 publications

(130 citation statements)

References 7 publications

(10 reference statements)

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“…When the azomethine groups are incorporated in to the polymer backbone, they exhibit good properties such as thermal stability [3,4], conductivity [5], fiber-forming ability [6,7], liquid crystalline behavior [8,9] and non-linear optical properties [10]. A drawback of the linear, aromatic rod-like poly(azomethine)s is their limited solubility in organic solvents.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Characterization of New Polyamides with Substitutions in the Pendent Benzylidene Rings

Ravikumar¹,

Saravanan

Saravanamani

et al. 2009

Designed Monomers and Polymers

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Aromatic polyamides with azomethine groups present in the polymer with -Cl, -OCH 3 , -N(CH 3 ) 2 and -OH substitutions in the pendent benzylidene rings were synthesized through polycondensation of new aromatic dicarboxylic acids with aromatic diamines using the phosphorylation technique in DMF. Direct polymerization of the monomers benzylidenamino phenyl 2,5-dicarboxylic acid (M1), 4 -hydroxy benzylidenamino phenyl 2,5-dicarboxylic acid (M2), 4 -methoxy benzylidenamino phenyl 2,5-dicarboxylic acid (M3), 4 -chloro benzylidenamino phenyl 2,5-dicarboxylic acid (M4) and (N,N-dimethylamino) benzylidenamino phenyl 2,5-dicarboxylic acid (M5) was carried out with commercial diamines, 4,4 -methylenedianilene and 4,4-diaminobiphenyl, at 140 • C. FT-IR and 1 H-NMR spectroscopic analysis were used to characterize the monomers and polymers. The inherent viscosity values of polyamides are in the range 0.39-0.68. Due to the substitutions in the pendent benzylidene rings, the polymers show enhanced solubility. The thermal stability of the polyamides was evaluated using thermogravimetric analysis, and the thermogravimetric curves show the dependence of thermal stability on the nature of the substitutions in the benzylidene rings.

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Section: Introductionmentioning

confidence: 99%

Synthesis and Characterization of New Polyamides with Substitutions in the Pendent Benzylidene Rings

Ravikumar¹,

Saravanan

Saravanamani

et al. 2009

Designed Monomers and Polymers

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“…Aromatic poly(azomethine)s belong to a class of high performance materials that are known because of their excellent thermal stability, good mechanical properties and environmental resistance, [1][2][3][4] but more particularly as promising materials with optoelectrical, photonic and magnetic application. [5][6][7][8] Numerous types of aromatic poly(azomethine)s have been synthesized by the condensation between aromatic dialdehydes and diamines.…”

mentioning

confidence: 99%

Self-Assembling Polycondensation of 4-Aminobenzaldehyde. Preparation of Star-Like Aggregates of Cone-Shaped Poly(azomethine) Crystals

Kimura

Zhuang

Kida

et al. 2003

Polym J

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KEY WORDSSelf-Assembling / Polycondensation / Poly(azomethine) / Crystallization / Morphology / Aromatic poly(azomethine)s belong to a class of high performance materials that are known because of their excellent thermal stability, good mechanical properties and environmental resistance, 1-4 but more particularly as promising materials with optoelectrical, photonic and magnetic application. [5][6][7][8] Numerous types of aromatic poly(azomethine)s have been synthesized by the condensation between aromatic dialdehydes and diamines. However, their high melting points and low solubility usually make them inaccessible for processing by conventional techniques. In order to improve their intractability, several approaches such as the introduction into the main chain of flexible aliphatic segments, bulky lateral substituents or fluorine groups have been attempted so far. [9][10][11][12] We have been studying on the morphology control of intractable polymers during solution polymerization, and succeeded in preparing the whiskers of poly(poxybenzoyl) and other aromatic polyesters by polymerization in liquid paraffin (LPF). [13][14][15][16][17][18] These whiskers are formed by the reaction-induced crystallization of oligomers during solution polymerization. The polymer chains are aligned along the long axis of the whiskers and they show single crystal nature. This morphology and the chain alignment are desirable to endow the essential properties for industrial materials such as organic reinforcements. The formation mechanism of these whiskers contains the following three steps: (1) When the degree of polymerization of the oligomers exceed a critical value, they are precipitated from the solution to form lamellae. (2) The lamellae pile up in the form of needle-like crystals with spiral growth.(3) Post-polymerization occurs topochemically in the needle-like crystals, and the whiskers consisting of high molecular weight extended polymer chains are eventually formed. 14 The preparation method of the whisker can be recognized as the self-assembling polycondensation accompanied by the reaction-induced crystallization of oligomers, and it is a very valuable method for the morphology control of intractable polymers to overcome the antagonistic problem between intractability and properties.In many reports it has been very difficult to obtain the high molecular weight poly(azomethine) (PAZM). One of reasons is that aromatic poly(azomethine)s are precipitated in the solution during polycondensation because of the low solubility. 12 Much effort was devoted recently to preparing soluble and fusible aromatic poly(azomethine)s in many different ways. [19][20][21] However, the modification of polymer chain structures sacrifices their essential properties derived from their straight rigid-rod structures. Precipitation during polymerization is of advantage to control the morphology by means of the reaction-induced crystallization of oligomers as described before. In this study, we report the morphology of PAZM crystals prepared by the self...

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“…In time, the red color disappears and a colorless solution is obtained, the protonated structure is not stable and hydrolysis of -CH=N-linkages takes place. The acid-catalyzed hydrolysis of azomethine linkage from PAMs dissolved in acidic solutions is known [42] and was investigated by Yang and Jenekhe [43,44]. If some drops of diluted HCl solution are added to a THF solution of P4 a strong red color was obtained which then gradually disappeared.…”

Section: Optical Propertiesmentioning

confidence: 99%

Synthesis and Characterization of Linear, Branched and Hyperbranched Triphenylamine-Based Polyazomethines

Grigoraş¹,

Stafie²

2009

Designed Monomers and Polymers

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Novel triphenylamine-based linear, hyperbranched and branched conjugated polyazomethines have been synthesized by free-catalyst solution polycondensation of 1,4-diaminobenzene with 4,4 -diformyl triphenylamine, 4,4 ,4 -triformyl triphenylamine and their mixture in different molar ratios. Linear polyazomethine has a good solubility in organic solvents while branched and hyperbranched polymers are partially soluble. A wholly soluble hyperbranched polyazomethine was obtained by end-capping of polymer at gelation point using a monofunctional aromatic amine, p-anisidine. Characterization of all polymers was made by 1 H-NMR, FT-IR and UV-Vis and photoluminescence spectroscopy and thermal methods. Electrochemical behavior of polymers was studied by cyclic voltammetry using thin films cast from THF solution on a platinum disc working electrode in acetonitrile solvent and tetrabutylammonium tetrafluoroborate as electrolyte.

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Aromatic azomethine polymers and fibers

Cited by 223 publications

References 7 publications

Synthesis and Characterization of New Polyamides with Substitutions in the Pendent Benzylidene Rings

Synthesis and Characterization of New Polyamides with Substitutions in the Pendent Benzylidene Rings

Self-Assembling Polycondensation of 4-Aminobenzaldehyde. Preparation of Star-Like Aggregates of Cone-Shaped Poly(azomethine) Crystals

Synthesis and Characterization of Linear, Branched and Hyperbranched Triphenylamine-Based Polyazomethines

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