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Thermal properties of cellulose acetate and its complexes with some transition metals

1999; Elsevier BV; Volume: 63; Issue: 2 Linguagem: Inglês

10.1016/s0141-3910(98)00108-6

1873-2321

A. A. Hanna, Altaf H. Basta, Houssni El‐Saied, Ihab F. Abadir,

Advanced Cellulose Research Studies

Cellulose triacetate–metal ion complexes were prepared using different metal salts. The products were characterized by using IR spectra, where the complex formation is emphasized. TGA and DTA of cellulose triacetate (CTA) and its complexes with Ni(II), Co(II), Cu(II) and Cr(III) chlorides were investigated from room temperature to 550°C. The TGA curves show that these samples degrade thermally in three steps which are attributed to dehydration, fragmentation of the macromolecular structure (the main thermal degradation step), and the carbonization of the product to ash. It is found that the main degradation step follows first-order kinetics. The complexation of cellulose acetate with metal ions increased its thermal stability. The calculated activation energy varied in the following sequence: CTA–Cu(II) > CTA–Ni(II) > CTA–Co(II) > CTA–Cr(III) > CTA. This observation was attributed to the electronegativity of the metal ion and the strength of the bond between the cellulose acetate and the metal ion.