Direct Polycondensation Of Dicarboxylic Acids Research Articles

Polyester Synthesis at Moderate Temperatures via the Direct Polycondensation of Dicarboxylic Acids and Diols Catalyzed by Rare-Earth Perfluoroalkanesulfonates and Bis(perfluoroalkanesulfonyl)imides

Recently, we reported that scandium trifluoromethanesulfonate [Sc(OTf)3] and scandium trifluoromethanesulfonimide could catalyze polycondensations of dicarboxylic acids and diols. Although these polycondensations were one-step and occurred at the moderate temperature of 35 °C, they required large amounts of the catalysts (ca. 1 mol %) and long reaction times (>100 h). Therefore, scandium catalysts having stronger electron-withdrawing ligands (scandium perfluorooctanesulfonate, scandium nonafluorobutanesulfonate, and scandium bis(nonafluorobutanesulfonyl)imide [Sc(NNf2)3]) were synthesized, and their catalytic efficiencies were tested. We have now demonstrated and report herein that scandium catalysts with the stronger electron-withdrawing ligands could catalyze the polycondensation of adipic acid and 3-methyl-1,5-pentanediol under conditions of a moderate temperature, a short time period, and a lesser amount of catalyst. Other rare-earth-metal catalysts containing ligands with strong electron-withdrawing ...

Novel phosphonated poly(1,3,4-oxadiazole)s: Synthesis in ionic liquid and characterization

A new class of poly(1,3,4-oxadiazole)s (PODs) with pendant phosphonic acid groups was synthesized via direct polycondensation of dicarboxylic acids and their dihydrazides using ionic liquid, namely 1-methyl-3-propylimidazoluium bromide ([mpim]Br), as a reaction medium, and triphenyl phosphite as a reaction activator. The polymers were obtained with inherent viscosities equal to 0.46–0.58 dL/g in two steps starting from polyhydrazides formation followed by thermal polycyclization under high vacuum. Polymers derived from 5-phosphonoisophtalic acid were soluble in traditional organic solvents, while application of 2-phosphonoterephthalic acid resulted in formation of insoluble gels. Such properties as thermal stability, glass transition temperatures, water uptake, molecular weights and proton conductivity of novel polymers were investigated in detail. A comparison between common poly(1,3,4-oxadiazole)s and their phosphorylated or phosphonated analogs having the same polymer backbone demonstrated that PODs with pendant phosphonic acid groups possess approximately the same thermal stability, but greater glass transition temperatures along with reduced solubility. Transparent flexible films cast from such novel polymers were characterized by high tensile properties, namely tensile strength of about 90–100 MPa and elongation up to 8%. The proton conductivity values measured at the temperature range from 20 to 90 °C varied from 4 × 10 −7 to 5 × 10 −6 S/cm at 100% relative humidity.

Thermostable aromatic poly(1,3,4-oxadiazole)s from multi-ring flexible diacids

A series of aromatic poly(1,3,4-oxadiazole)s, PODZs, was prepared either by direct polycondensation of dicarboxylic acids with hydrazine sulfate using the polyphosphoric acid/methanesulfonic acid mixture, or by thermal cyclodehydration of the corresponding poly(hydrazide)s. Various aromatic diacids containing flexible p-oxyphenylene joints and/or bulky isopropylidene or hexafluoroisopropylidene groups in the main chain were used to produce amorphous PODZs soluble in strongly polar organic solvents and having inherent viscosities up to 1.1 dl g −1. The polymers were characterized by Fourier transform infrared and 1H and 13C nuclear magnetic resonance spectroscopy, and their thermal properties were investigated by differential scanning calorimetry and dynamic thermogravimetric analysis. The glass transition temperatures, T g , lie in the range 190–295°C, and depend both on the number of aryloxy groups and on the presence of bulky groups. The PODZs show good thermal resistance in nitrogen up to 440°C.

Synthesis of Polyamides by Direct Polycondensation with 5-Methyl-2-chloro-3-phenyl-2,3-dihydro-1,3,4,2-oxadiazaphosphole as a New Condensing Agent

A new condensing agent, 5-methyl-2-chloro-3-phenyl-2,3-dihydro-1,3,4,2-oxadiazaphosphole (2) prepared from β-N-acetyl-phenylhydrazine (1) and phosphorus trichloride was used for the synthesis of amides and polyamides. The condensing agent was useful for the preparation of amides from carboxylic acids and amines. The direct polycondensation of dicarboxylic acids with aromatic diamines using the condensing agent in the presence of pyridine proceeded at room temperature to produce polyamides with inherent viscosities up to 1.9 dl g−1.

Synthesis of polyamides by direct polycondensation with phenylphosphonic anhydride as an activating agent

AbstractA new activating agent for amide condensations, phenylphosphonic anhydride (1), was prepared by the reaction of phenylphosphonic dichloride with water. The new activating agent was found to be useful for the preparation of amides from carboxylic acids and amines. The direct polycondensation of dicarboxylic acids with aromatic diamines using the activating agent in the presence of pyridine proceeds at 60°C to produce polyamides with inherent viscosities up to 1,1 dl/g. Furthermore, the activating agent was used for chemoselective polyamidation; that is, polyamides from dicarboxylic acids and diamines containing various functional groups were prepared without special protection of acylating‐sensitive groups.

Synthesis of poly(benzoxazinone)s by direct polycondensation of dicarboxylic acids with bis(anthranilic acid)s

AbstractA convenient method for the synthesis of poly(benzoxazinone)s of high molecular weights has been developed. These polymers were prepared readily by direct polycondensation of aromatic dicarboxylic acids containing phenyl ether structures with bis(anthranilic acid)s using phosphorus pentoxide/methanesulfonic acid (PPMA) as a condensing agent and solvent. Polycondensations proceeded smoothly and were completed within several hours at 140°C to produce poly(benzoxazinone)s with inherent viscosities up to 2.6 dL/g. The synthesis of 2‐substituted benzoxazinones by the reaction of aromatic carboxylic acids or dicarboxylic acid with anthranilic acid in PPMA was studied in detail to demonstrate the feasibility of the reaction for polymer formation. The thermogravimetry of the aromatic poly(benzoxazinone)s showed 10% weight loss in air and nitrogen around at 440 and 460°C, respectively.

Synthesis of Polyamides by Direct Polycondensation with Propylphosphonic Anhydride as an Activating Agent

A 50 wt% solution of the propylphosphonic anhydride in NMP as an activating agent was used for the synthesis of amides and polyamides. The activating agent was useful for the preparation of amides from carboxylic acids and amines. The direct polycondensation of dicarboxylic acids with aromatic diamines using the activating agent in the presence of pyridine proceeded at 100°C to produce polyamides with inherent viscosities up to 1.6 dl g−1. Furthermore, the activating agent was used for the chemoselective polyamidation; that is, polyamides from dicarboxylic acids and diamines containing various functional groups were prepared without special protection of the acylation-sensitive groups.

Synthesis of poly(1,3,4‐oxadiazole)s by direct polycondensation of dicarboxylic acids with hydrazine sulfate using phosphorus pentoxide/methanesulfonic acid as condensing agent and solvent

AbstractA convenient method for the synthesis of poly(1,3,4‐oxadiazole)s of high molecular weights has been developed. These polymers were prepared readily by the direct polycondensation of dicarboxylic acids with hydrazine sulfate (1) using phosphorus pentoxide/methanesulfonic acid (PPMA) as both a condensing agent and solvent. Polycondensation of aliphatic dicarboxylic acids with 1 proceeded even at room temperature and produced poly(1,3,4‐oxadiazole)s with inherent viscosities up to 1.4 dL/g. The synthesis of aromatic poly(1,3,4‐oxadiazole)s from aromatic dicarboxylic acids containing phenyl ether structures was carried out by a one‐pot procedure because the preactivation of dicarboxylic acids was required. The synthesis of 2,5‐disubstituted‐1,3,4‐oxadiazoles by the reaction of carboxylic acids with 1 in PPMA was studied to demonstrate the feasibility of the reaction for polymer formation. The thermogravimetry of the aromatic poly(1,3,4‐oxadiazole)s showed 10% weight loss both in air and in nitrogen at 440–490°C.

Synthesis of Polyamides by Direct Polycondensation with Diphenyl 2,3-Dihydro-2-oxo-3-benzothiazolyl Phosphate as a New Activating Agent

A new activating agent for amide condensations, diphenyl 2,3-dihydro-2-oxo-3-benzothiazolyl phosphate, was prepared by the reaction of 2(3H)-benzothiazolone with diphenyl phosphorochloridate in the presence of triethylamine in acetonitrile at room temperature. The new activating agent was found to be useful for the preparation of amides from carboxylic acids and amines. The direct polycondensation of dicarboxylic acids with aromatic diamines using the activating agent in the presence of triethylamine proceeded at room temperature to produce polyamides with inherent viscosities up to 1.1 dl g−1. Furthermore, the activating agent was used for the synthesis of polyamides from bis(oxo carboxylic acid)s or 2,6-pyridinedicarboxylic acid and 4,4′-oxydianiline.

Synthesis of poly(benzoxazole)s by direct polycondensation of dicarboxylic acids with 3,3′‐dihydroxybenzidine dihydrochloride using phosphorus pentoxide/methanesulfonic acid as condensing agent and solvent

AbstractA convenient method for the synthesis of poly(benzoxazole)s of high molecular weights has been developed. These polymers were prepared readily by direct polycondensation of aromatic dicarboxylic acids containing phenyl either structure with 3,3′‐dihydroxybenzidine dihydrochloride using phosphorus pentoxide/methanesulfonic acid (PPMA) as condensing agent and solvent. Polycondensations proceeded fast and was completed within 5 h at 140°C and produced poly(benzoxazole)s with inherent viscosities up to 4.6 dL/g. Model compound work was performed in detail to demonstrate the feasibility of the reaction for polymer formation. The thermogravimetry of the aromatic poly(benzoxazole)s showed 10% weight loss in air and nitrogen at 450–505°C and 465–535°C, respectively.

Synthesis of Poly(benzothiazole) by Direct Polycondensation of Dicarboxylic Acids with 2,5-Diamino-1,4-benzenedithiol Dihydrochloride Using Phosphorus Pentoxide/Methanesulfonic Acid as Condensing Agent and Solvent

A convenient method for the synthesis of poly(benzothiazole) of high molecular weights has been developed. These polymers were prepared readily by direct polycondensation of aliphatic, alicyclic, and aromatic dicarboxylic acids containing phenyl ether structures with 2,5-diamino-1,4-benzenedithiol dihydrochloride using phosphorus pentoxide/methanesulfonic acid (PPMA) as both a condensing agent and solvent. Polycondensations proceeded smoothly and were completed within several hours at 140°C to produce poly(benzothiazole)s with inherent viscosities up to 2.9 dl g−1. The thermogravimetry of the aromatic poly(benzothiazole)s showed 10% weight loss in air and nitrogen at 405—490°C and 450—595°C, respectively.

Synthesis of polyketones by direct polycondensation of dicarboxylic acids with diaryl compounds using phosphorus pentoxide/methanesulfonic acid as condensing agent and solvent

Reaction modele: diphenyl ether plus acide benzoique. Polycondensation pendant plusieurs termes entre 50 et 100°C