Thermal behaviour and spectral studies on cotton cellulose modified with phosphorus, sulphur and metals

Abstract

The potential flame retardancy of cellulose benzyithiophosphate (CBTP) and its metal co mplexes has been investigated by their thermal degradation behaviour using TG and DSC techniques from ambient temperature to 600°C in air and nitrogen atmosphere. From the resulting data of TG curve using Broido method, the activation energies of CBTP and its

metal complexes for decomposition stage arc found to be in the range 31-45 kJ mol^-1 and are lower than that of cellulose (165.85 kJ mol^-1) in air atmosphere. Modified cellulose samples, when heated, give rise to high char yields. The values of Δ<i>H </i>have also been found reduced and spread in wide range of temperature significantly by introducing phosphorus, sulphur

and metals in cellulose. The FTIR spectra of chars of modified cellulose indicate that dehydration takes place and compounds containing C=O, C=C, P-S-P and P=O groups are formed. These and related observations suggest that such derivatisation may give rise to novel flame retardant treatments for cellulosic materials.