Copolycondensation of various compositions of isophthalic acid and terephthalic acid with hydroquinones or bisphenols by tosyl chloride/dimethylformamide/pyridine

Abstract

The polycondensation of isophthalic acid (IPA)/terephthalic acid (TPA) with aromatic diols by tosyl chloride/dimethylformamide/pyridine in solution was examined through changes in the IPA/TPA compositions, the kinds of dihydroxyl components, the periods of their addition, and the reaction temperatures. The reaction proceeded favorably at IPA/TPA ratios of 70/30 to 50/50, similarly to an earlier report on the interfacial reaction. The effects of the compositions were significant in the reactions with monosubstituted hydroquinones. The results were examined from distributions of the resulting oligomers prepared at a reaction extent of 0.7, determined by gel permeation chromatography. The reaction producing better results exhibited distributions closer to the theoretical ones. The period of addition also favorably affected the distributions as well as the results of the polycondensation. These results were attributed to the change in the reaction method, in which the diols reacted with the aggregates that formed from the activated IPA and TPA. The change was likely caused by the degree of association of IPA and TPA in the aggregates, on the basis of melting points and IR spectra of mixtures of dimethyl esters of IPA and TPA prepared by the quenching of the aggregates with methanol. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2321–2328, 2004

Combined effect of isophthalic acid and polyethylene glycol in polyethylene terephthalate polymer on thermal, mechanical, and gas transport properties

“…Pure PET shows T g of 80.39°C and for IPA‐PEG copolymer series T g values are within 2°C difference up to 4% IPA‐PEG and above 4% IPA‐PEG T g starts decreasing rapidly. As reported elsewhere,15–30 the reduction of T g in PET is due to the kinking effect in the molecular structure, which arise due to the copolymer addition. The addition of comonomers in PET increases the T ch temperature and suggests that the crystallization takes place at higher temperature.…”

“…Replacing PTA with IPA creates a kink in the PET polymer chain. This interferes with crystallization by affecting the periodicity of molecular structure and thereby lowers the polymer's melting point 18–23. In some cases, for example, CHDM are also added to the polymer backbone in place of MEG.…”

Preparation of new poly(amide–imide)s with chiral architectures via direct polyamidation reaction

“…[12][13][14] Higashi et al have developed new condensing agents for direct polyesterfication. [15][16][17][18] Because of importance of methionine and the existence of flexible group in this amino acid, to induce the chirality and improve the solubility of the polymers, in continuation of our study to develop new OAPs via direct polycondensation, [19][20][21][22] here, we report the application of the Vilsmeier adduct derived from TsCl/DMF/Py for direct polyamidation of new optically active bis(paminobezoic acid)-N-trimellitylimido-L-methionine (5) monomer with different aromatic diamines.…”

Synthesis, characterization, and properties of poly(amide‐imide)s from a new diimide‐diacid by direct polycondensation with various diamines

“…22, 23 One of convenient and efficient ways of synthesis of high‐molecular weights PAIs, is the direct polycondensation of imide‐containing dicarboxylic acids with aromatic diamines by means of the Yamazaki–Higashi phosphorylation technique. 24–26 The direct polycondensation route is a very useful laboratory method and avoids using moisture‐sensitive acid chlorides, or isocyanates. 27–29…”