Chain-coupling reaction of amine-terminated oligomers by bis(4-monosubstituted-5(4H)oxazolinones)

摘要

Bis(5(4H)oxazolinones) derived from naturally occurring alpha-amino acids were reacted with amine-terminated polyethers and polyamides in the bulk at 175-200 degrees C. Model reactions were also carried out using primary alkylamines. The reactions were studied by means of SEC, and H-1 and C-13 NMR, and the resulting polymers were characterized by DSC and TGA. The chain-coupling reaction is extremely fast and yields high molar mass copolymers containing peptide linkages in less than 5 min. The NMR spectra of model compounds and polymers were fully assigned, showing that the oxazolinone/amine polyaddition reaction proceeds in the expected way, without any noticeable side reaction. The polymers exhibit lower crystallinity, higher T-g and a melting temperature close to or lower than that of the starting oligomers. References: 16