Cyclo‐tetrakis‐hexamethylenadipinamid

Zahn, Helmut; Kusch, Peter

doi:10.1002/cber.19650980825

Cited by 7 publications

(1 citation statement)

References 17 publications

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“…Herman Stetter and Helmut Zahn pioneered the stepwise synthesis of well-defined caprolactam cyclic AB oligomers and linear 66 nylon AABB oligomers. − Stetter later used interfacial polycondensation at high dilution to synthesize AABB cyclic oligomers …”

Section: Introductionmentioning

confidence: 99%

Cyclic and Linear Polyamides from Polycondensations of Hexamethylenediamine and m-Xylylenediamine with Adipic, Isophthalic, and Terephthalic Acids

et al. 2009

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Cyclic and linear oligoamides were extracted with methanol in 0.1-0.9% yield from condensation polymers of hexamethylenediamine or m-xylylenediamine with mixtures of adipic, isophthalic, and terephthalic acids. The parent polymers and methanol extracts were analyzed using mass spectrometry, and the extracts, in which the smaller molecules were concentrated by a factor of about 200, were studied by nuclear magnetic resonance (NMR) spectroscopy. Small cyclic oligoamides dominated all of the extract spectra. Cyclic monomers were observed with adipic acid but not with the aromatic acids. Cyclic dimers and trimers predominated and yields of higher cyclics decreased rapidly with increasing ring size, especially in the extracts. The degree of incorporation of the acids into small cyclics was adipic > isophthalic > terephthalic. NMR spectra of extracts from all polymers containing terephthalic and/or isophthalic acid units showed linear oligomers with benzoyl end groups, which presumably arose from thermal decarboxylation during polymerization, lowering the polymer molecular weight and affecting other polymer properties.

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