Carboxymethyl cellulose–gelatin complexes

Carboxymethyl cellulose (CMC) complexes with gelatin (G) were prepared electrochemically (12 V, on chromium–nickel stainless steel electrodes) from aqueous blends of initial CMC/G ratio=1:0.5, 1:1 and 1:2, at pH 9, 10 and 11. The resulting complexes always contained lesser G than in the electrolytic solution. The 1:1 complexes resulted from the CMC/G=1:2 solution. The complexes were slightly more thermally stable than plain CMC and G but their glassy transition took place at a slightly lower temperature. Solubility tests, thermogravimetric, differential thermal analysis, and FTIR spectroscopy suggested that apart from hydrogen bonds and dispersion forces also strong interactions between carboxyl groups of CMC and peptide moieties of G were involved in the formation of CMC–G complexes.