Authors:C. Tian, Z. Shi, H. Zhang, J. Xu, J. Shi, and H. Guo
The thermal degradation of cotton cellulose treated with chemical mixtures containing P and N was studied by thermal analysis,
infrared spectroscopy, Char yield and limiting-oxygen-index (LOI). Our experiments demonstrated the following facts. The temperatures
and activation energies of pyrolysis were lower for cotton cellulose treated with flame retardants than those for untreated
samples and the values of Char yield and LOI were greater for treated cotton than those for untreated one.
Complexes of cell–THPC–urea–ADP with transition metal ion Co2+ and lanthanide metal ions such as La3+, Ce4+, Nd3+ and Sm3+ have been prepared. The thermal behavior and smoke suspension of the samples are determined by TG, DTA, DTG and cone calorimetry.
The activation energies for the second stage of thermal degradation have been obtained by following Broido equation. Experimental
data show that for the complexes of cell–THPC–urea–ADP with the metal ions, the activation energies and thermal decomposition
temperatures are higher than those of cell–THPC–urea–ADP, which shows these metal ions can increase the thermal stability
of cell–THPC–urea–ADP. Moreover, these lanthanide metal ions can more increase thermal stability of samples than do the transition
metal ion Co2+. The cone calorimetry data indicate that the lanthanide metal ions, similar to transition metal Co2+, greatly decrease the smoke, CO and CO2 generation of cell–THPC–urea–ADP, which can be used as smoke suppressants.
The degradation of cotton cellulose polymer by Li+-, K+- and NH4+-exchanged montmorillonite has been studied. A general reaction scheme is proposed. The mechanism of this reaction would most probably involve chain breaking and increasing the reducing power of cellulose polymer by dissociation of water molecules coordinated to the central metal ion.
Authors:R. Bluďovský, M. Procházka, and J. Kopoldová
Cotton cellulose was irradiated under oxygen or nitrogen atmosphere with60Co irradiator in the dose range 0-130 kGy. The following compounds were found: acetaldehyde, acetone, arabinose, desoxysaccharides, formaldehyde, formic acid, glucuronic and gluconic acids, glucose, malonaldehyde, oxalic acid and xylose. No changes were observed in qualitative composition of radiolytical products formed in oxygen and nitrogen atmospheres. On the other hand the presence of oxygen increased the yields of all radiolytical products, particularly of formic acid, malonaldehyde and other carboxyl groups. A mechanism of formaldehyde formation is discussed.
Several samples of native (untreated), mercerized prior to ammonia treatment and ammonia-treated Egyptian cotton fabric strips have been prepared. On these samples several measurements were carried out, including infrared and electronic absorption spectroscopy, temperature dependent DC electric conductivity measurements and -radiation exposure. Detailed accounts of the spectral properties and phase constitution of NH3-treated cotton celluloses were correlated with their electrical properties. Finally, the mechanism of electric conduction in NH3-treated Egyptian fabric strips was put forward and correlated for the first time with the spectral properties and phase constitution of cotton textiles.
Authors:Hadi Fallah Moafi, Abdollah Fallah Shojaie, and Mohammad Ali Zanjanchi
Moharram , MA , Nasr , TZAE , Hakeem , NA . X-ray diffraction and infrared studies on the effect of thermal treatments on cottoncelluloses . J Polym Sci Polym Lett Ed 1981 19 : 183 – 187 10.1002/pol.1981