Schiff base polymers derived from 2,5‐diformylfuran

Polymerization of 2,5‐diformylfuran with two primary amines was carried out in acetonitrile and ethanol at room temperature. The reaction was characterized using a combination of mass spectroscopy and NMR spectroscopy, which revealed the clean formation of the imine –CHN− functional group. Although some cyclic products were detected from mass spectroscopy, the ring size was limited to products that have the −CHN− group only in anti‐geometry. The furan Schiff bases exhibit good thermal stability. While mass spectra evidenced oligomers of different lengths, cross‐polarization magic angle spinning 13C NMR spectra of the insoluble polymer revealed the linear structure as proposed.