Abstract
Studies on the flame-proofing and thermal stability imparted by the combination of chromium, manganese, iron, cobalt, nickel, copper and zinc with cellulose ammonium phosphate were carried out by thermal, morphological and spectroscopic techniques. The samples were subjected to differential thermal analysis and thermogravimetric studies from ambient temperature to 900°C. Thermodynamic properties were obtained by using the Broido method on thermogravimetric curves. Infrared and reflectance UV-visible spectra of samples heated to significant temperatures were obtained. The samples showed low decomposition temperatures, low energies of activation and high char yields. Unmodified cellulose and other samples were pyrolysed in a temperature-programmed solid probe of a field ionization mass spectrometer, and mass spectra were recorded continuously throughout the pyrolysis to determine the relative amounts of volatile materials. In the treated cellulose samples the fractions of non-fuel volatiles increased and those of anhydroglucoses decreased. These observations confirm their flame-retardant effect. Scanning electron microscopic studies of the samples threw light on the morphological changes in the thermal degradation range. Based on the above studies, a mechanism of the thermal degradation of metal complexes of cellulose ammonium phosphate is proposed.