ABSTRACT 



This study was undertaken to determine the thermal properties of, and 

 the pyroly sis products from, western cottonwood (Populits trichooarpa) and 

 two of its major components: cellulose and xylan. The modifications due to 

 treatment of the wood and its components with an acid and alkali were also 

 documented. Differential thermal analysis (DTA) and thermogravimetric 

 analysis (TGA), as well as direct pyrorysis into a temperature-programed 

 gas-liquid chromatograph, were used in this investigation. 



The components of cottonwood were found to generally behave the same 

 in a thermal environment, both in isolated form and when combined in the 

 whole wood. The hemicellulose, xylan, was completely pyrolyzed prior to 

 the onset of cellulose pyrolysis. The acid salt treatment decreased pyrorysis 

 rate of wood, cellulose, and xylan, and increased char, water, and furan 

 compounds while decreasing the major two and three carbon fragments. The 

 alkali treatment also decreased the pyrolysis rate and increased the produc- 

 tion of char and water, but decreased the furan compounds while increasing 

 the two and three carbon fragments. 



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