Syntheses and properties of polyamides from glucosamine and glucose derivatives

Starting from D‐glucosamine, the synthesis of various differently modified methyl and benzyl 2,6‐diaminosaccharides 11, 12, 17 and 18 was accomplished. Interfacial and solution polycondensation of those diamino derivates with aromatic and aliphatic acyl chlorides yielded polyamides 34, 35, 36 and 37a–d which were characterized by 1H NMR spectroscopy and their inherent viscosities. The presence of an anomeric benzyl group in 12 did not decrease the reactivity of the 2‐amino function. The free hydroxy functions in polyamides 35a–b were acetylated to give polyamides 39a–b. Partially blocked polyamides 36a–d had similar properties as unprotected polyamides 34–35a–d. Under corresponding conditions di‐O‐acylated diaminosaccharide 18 gave only oligomer. Number‐average molecular weights were obtained from gel‐permeation chromatography to be 10300 < M̄n < 24000 (interfacial polycondensation), corresponding to number‐average degrees of polymerization up to P̄n = 64, whereas polycondensation in solution afforded only M̄n values between 2000 and 3000. Starting with D‐glucose the synthesis of a C‐glycosidic diaminosaccharide 28 was developed. This reacted to polyamides 38a–d which showed thermal stability up to 280°C.