ABSTRACT 



Differential thermal, thermogravimetric, and derivative thermogravimetric 

 analyses were used to study the effects of two important fire retardant chemicals — 

 ammonium phosphate and ammonium sulfate — on the pyrolysis and combustion of 

 cellulose. To aid in the interpretation of treated cellulose thermograms, the ther- 

 mal behavior of the fire retardant chemicals was investigated. 



An increase in the concentration of either flame retardant lowered the 

 threshold temperature and activation energy required to initiate cellulose pyrolysis 

 and combustion, generally decreased maximum weight loss rates, and caused an 

 increase in the production of residue or char. Although these general similarities 

 were found, there were distinct differences in the temperatures at which the rates 

 charged when treated with the same quantity (on a molar fraction basis) of retardant 

 chemical. The difference in which these chemicals alter pyrolysis and combustion 

 is due to a difference in the availability of the inorganic fraction involved in the re- 

 action or to a difference in the reaction mechanism, or both. 



The study demonstrated that direct comparison of retardant chemicals on 

 the basis of their thermal effects on pyrolysis and combustion at one treatment 

 level could lead to erroneous interpretation and improper classification. 



