Synthesis Of Aromatic Polyesters Research Articles

Synthesis of Aromatic Polyesters with Pendent Carboxyl Groups from Diphenolic Acid, Bisphenol a and Isophthaloyl Chloride by Interfacial Polycondensation

Aromatic polyesters bearing pendent carboxyl functionalities were prepared by interfacial polycondensation of diphenolic acid, bisphenol A and isophthaloyl chloride with tetrabutylammonium chloride as phase transfer catalyst. The copolyester composition was confirmed with HPLC analysis. The polymerization process and composition of the copolyesters were examined by considering influences of reaction temperatures, time, ratio of feeds, agitation speeds.

New approaches to the synthesis of aromatic polyesters

A new method of the synthesis of high molecular polybutylene terephthalate (PBT) is developed with the use of Irganox 1010, tris(nonylphenyl) phosphite and hypophosphite as stabilizers and boron nitride or boron oxide as a catalyst is proposed.

Synthesis of well‐defined aromatic polyesters by chain‐growth polycondensation under suppression of transesterification

AbstractFor the synthesis of aromatic polyesters with defined molecular weights and narrow molecular weight distributions (MWDs), we investigated the chain‐growth polycondensation of active amide derivatives of 4‐hydroxybenzoic acid, 1a and 1b, having an octyl or 4,7‐dioxaoctyl side chain, respectively. To suppress the transesterification of the polymer backbone with the monomer, the polymerization of 1 was carried out in tetrahydrofuran (THF) at −30 °C in the presence of initiator 2 and Et3SiH/CsF/18‐crown‐6, which generated a hydride ion as a base in situ. The number‐average molecular weight (Mn) of poly1a was controlled, and narrow MWDs were maintained, until the [1a]0/[2]0 feed ratio was 14.3 (Mn ≤ 3500), whereas that of poly1b was controlled until the feed ratio was 30 (Mn ≤ 7250). The difference stemmed from the higher solubility of poly1b in THF. This chain‐growth polycondensation was applied to the synthesis of a diblock copolyester of 1a and 1b of a defined architecture. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4109–4117, 2005

Investigation of Aromatic Polyester Synthesis by the Chain-Growth Polycondensation Method

Synthesis of aromatic polyesters by chain-growth polycondensation of activated 4-hydroxybenzoic acid derivatives (1) was investigated. Model reactions of ester formation between active compounds (6 and 7) and phenolic nucleophile (8) gave the best result when 3-arylcarbonyl-2-benzothiazolone derivatives were used with tertiary amines in CH2Cl2. Therefore, we designed and synthesized 3-(4-hydroxy-3-octylbenzoyl)-2-benzothiazolone (1h) as a monomer. The Mn− and Mw/Mn−conversion curves of the polymerization of 1h with initiator suggested that transesterification between polymer and monomer occurred in the late stage of polymerization. Investigation of the effects of bases and initiators revealed that the transesterification at the initiator end was minimized by using 3-(4-benzoyloxybenzoyl)-2-benzothiazolone (7h) and diisopropylethylamine as an initiator and a base, respectively. When the ratio of initiator 7h to monomer 1h was 20 mol %, the polycondensation proceeded in a chain-growth manner to give aromati...

Synthesis of aromatic polyesters using polymeric catalysts having quaternary ammonium salt groups

The preparation of polyester (PQ) and copolyester (PQ-DIOL) catalysts having quaternary ammonium groups was performed, and an aromatic polyester (PEA) was directly synthesized from isophthaloyl chloride and diphenolic acid by aqueous/organic interfacial polycondensation using these polymer catalysts. The yield and molecular weight of the polyester were affected by the structure of the pendant quaternary ammonium groups.

Synthesis of aromatic polyesters and polyamides by alternating copolymerizations of 1,4‐dicarbonyl‐1,4‐dihydronaphthalene with bezoquinones and benzoquinone diimines

Synthesis of aromatic polyesters and polyamides by alternating copolymerizations of 1,4‐dicarbonyl‐1,4‐dihydronaphthalene with bezoquinones and benzoquinone diimines

Synthesis of aromatic polyesters and polyamides by alternating copolymerizations of 1,4-dicarbonyl-1,4-dihydronaphthalene with bezoquinones and benzoquinone diimines

1,4-Dicarbonyl-1,4-dihydronaphthalene (1) was synthesized by the dehydrochlorination reaction of 1,4-dihydronaphthalene-1,4-dicarbonyl chloride with triethylamine and obtained as its very dilute solution, but it easily polymerized in the concentration as high as 0.1 mol/L to give its polymer. 1 generated in situ by the dehydrochlorination reaction of 1,4-dihydronaphthalene-1,4-dicarbonyl chloride in a deoxygenated toluene polymerized alternatingly with benzoquinones such as 2-dodecylthio-p-benzo-quinone, 2,5-di(tert-butyl)-p -benzoquinone,p -benzoquinone, and 2,3-dichloro-5,6-dicyano-p-benzoquinone, and with benzoquinone diimines such as N,N'-diethoxycarbonyl-p-benzoquinone diimine, N,N'-dibenzoyl-p -benzoquinone diimine, and N,N'-diphenyl-p-benzoquinone diimine to give aromatic polyesters and polyamides, respectively.

Synthesis of aromatic polyesters having pendant carboxyl groups in the side chains and conversion of the carboxyl groups to other reactive groups

AbstractAromatic polyester, copolyester, and poly(ester‐amide‐thioester) having pendant carboxyl groups are directly synthesized by the organic phase/water phase interfacial polyconden‐sation using low‐molecular and polymeric phase transfer catalysts. Spectral analysis of the resulting polymers indicates that the nucleophilicity of salts of phenols to diacid chloride is far higher than that of salts of carboxylic acids and chemoselective esterification occurs in a 100% yield. Even if the polymeric catalyst having amino acid moiety as a nucleophilic group is used in the polycondensation, the polymers do not contain anhydride groups. The polyester can be almost quantitatively converted to polymers with different reactive groups by reacting the pendant carboxyl groups with alkyl halides in a DMAc‐H2O mixture con‐taining K2CO3. A bifunctional catalytic mechanism is proposed for the chemical modification of the polyesters. © 1995 John Wiley & Sons, Inc.

Enzymatic Synthesis of Various Aromatic Polyesters in Anhydrous Organic Solvents

Lipases and proteases from various sources were tested in aromatic polyester synthesis in organic solvents. A commercial protease from Bacillus licheniformis efficiently catalyzed the transesterifica-tion of a diester of terephthalic acid and 1,4-butanediol in anhydrous tetrahydrofuran (THF). This protease was used as a catalyst in the synthesis of aromatic polyesters in THF. Oligomers with average molecular weights from 400 to 1000 daltons were obtained using various diols and aromatic diesters.

New polymer syntheses, 56. Synthesis of aromatic polyesters by condensation of silylated aromatic dicarboxylic acids and acetylated diphenols

New polymer syntheses, 56. Synthesis of aromatic polyesters by condensation of silylated aromatic dicarboxylic acids and acetylated diphenols

Synthesis of aromatic polyesters by direct polycondensation with triphenylphosphine dichloride

AbstractAromatic polyesters of high molecular weights were prepared by the direct polycondensation reaction of dicarboxylic acids and bisphenols or hydroxybenzoic acids with triphenylphosphine dichloride as a new condensing agent. Reaction conditions, including the amount of reagents and the concentration of monomer, solvent, and acid acceptor, were investigated. The aromatic polyester with the solution viscosity of 1.66 dL/g was obtained from bisphenol. A and terephthalic and isophthalic acid in quantitative yield under the optimum condition. The principal advantage of this condensing agent is that, based on the recycling system, recovered triphenylphosphine oxide can be reconverted to the reactive triphenylphosphine dichloride by treating with phosgene or oxalyl chloride.

Mechanism of Catalyst Action in Interfacial Polycondensation of Chlorobisphenol and Isophthaloyl Chloride

Abstract The mechanism of action of quaternary ammonium salt catalysts in the synthesis of aromatic polyesters was investigated. The possibility of formation of compounds of these salts and bisphenols and their extraction in the form of an ion pair into the organic phase was investigated. The structure of the compounds obtained was determined.

Synthesis of Aromatic Polyesters by Interfacial Polycondensation Using Immiscible Binary Solvents

Synthesis of Aromatic Polyesters by Interfacial Polycondensation Using Immiscible Binary Solvents