Characterization of recycled celluloses: Thermogravimetry Fourier transform infra-red coupling and thermogravimetry investigations

Thermogravimetry/Fourier transform infra-red coupling analysis and thermogravimetry were performed on recycled celluloses of different compositions. Four samples were studied: one from ashless filter paper, two from recycled celluloses with 80% of chemical paper pulp and 85% of mechanical paper pulp respectively, and one from recycled cellulose the composition of which is not known. The major volatile products formed during the degradation process were identified by means of thermogravimetry/Fourier transform infra-red coupling analysis. From thermogravimetry we show that the degradation process of such recycled celluloses may be divided into two stages. The activation energies for these degradation processes were obtained using the Kissinger and Broido methods. Our data show that Broido's method allows the identification of each recycled cellulose from a knowledge of the activation energies (E(a)) and the critical rate of transformation (alpha(c)). (C) 1996 Published by Elsevier Science Limited