01463naa a2200229 a 450000100080000000500110000800800410001910000230006024501230008326000090020652007590021565000130097465000170098765300230100465300140102765300240104170000180106570000220108370000220110570000260112777300800115320376472024-02-03       2015    bl uuuu     u00u1 u    #d1 aSOUZA, N. L. G. D.  aSynthesis, Vibrational Spectroscopic and Thermal Properties of Oxocarbon Cross?Linked Chitosan.h[electronic resource]  c2015  aIn this work specimens of chitosan which have been cross-linked covalently and ionically with different oxocarbon and pseudo-oxocarbon anions have been synthesised and characterized using infrared and Raman spectroscopic techniques, solid state 13C nuclear magnetic resonance (NMR) and by thermogravimetry. According to the spectroscopic and thermal results, ionically crosslinked chitosans are obtained with squarate, croconate and rhodizonate ions as crosslinking agents, whereas covalently crosslinked chitosan can be obtained when squaric acid is used as the crosslinking agent; the same products are not observed when the pseudo-oxocarbon anion croconate violet is used, which can be attributed to the low basic strength of the crosslinking species.  achitosan  acrosslinking  aInfrared and Raman  aOxocarbon  aSolid state 13C NMR1 aSALLES, T. F.1 aBRANDAO, H. de M.1 aEDWARDS, H. G. M.1 aOLIVEIRA, L. F. C. de  tJournal of the Brazilian Chemical Societygv. 26, n. 6, p. 1247-1256, 2015.