The use of activated bis-pentachlorophenyl esters of dicarboxylic acids in synthesis of polyamides

Katsarava, Ramaz; Kunchuliya, D.P.; Avalishvili, L.M.; Andronikashvili, G. G.; Zaalishvili, M.M.

doi:10.1016/0032-3950(79)90130-8

Cited by 7 publications

(1 citation statement)

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“…The acridine-based semiaromatic polyamides PA x Acr ( x = 6, 8, 10, 12) were then prepared by solution-phase polycondensation of the active ester monomer 4 with 1,6-hexanediamine, 1,8-octanediamine, 1,10-decanediamine, and 1,12-dodecanediamine, respectively (Figure ). − The N -hydroxysuccinimide side product was readily soluble in water, which greatly simplified workup. The advantage of this approach over Yamazaki–Higashi polycondensations using the free carboxylic acid is that it does not require an activating agent, which may suffer from competition with the acridine.…”

Section: Resultsmentioning

confidence: 99%

Semiaromatic Polyamides with Re-Entrant Chain Folding Templated by “U-Turn” Repeat Units

et al. 2021

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Biopolymers often show deterministic chain folding templated by repeat unit sequences whose conformations are locked in by intramolecular interactions. In this work, we have used repeat units based on rigid anthracene or acridine scaffolds, which we refer to as “U-turn” repeat units, to template chain folding reminiscent of β-serpentine folds in bulk synthetic polyamides. Unlike the rigid kinked repeat units present in certain commercial semiaromatic polyamides, the acridine-based U-turn repeat units did not impede crystallization in the polyamides, whose crystalline phase was shown to be stabilized by infinite arrays of intermolecular hydrogen bonds and π–π interactions between the acridine units. This led to a unique layered crystalline structure characterized by a well-defined lamellar thickness that depended on the length of the aliphatic spacers between the U-turn repeat units and regular adjacent re-entrant chain folding, which is not usually expected for semiaromatic polyamides crystallized at high supercooling. Our work hence provides the first example of the introduction of deterministic chain folding into a nonpeptidic polyamide in order to tailor its crystalline morphology and may consequently open up new perspectives for the molecular design of structural materials.

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Section: Resultsmentioning

confidence: 99%