The pyrolysis products from Cottonwood cellulose and xylan, with and without 

 treatment, were identified using pyrolysis GLC. To analyze the volatiles, about 12 to 

 20 mg. of the powdered samples were placed in a small aluminum boat and pyrolyzed at 

 600° C . in a Perkin Elmer pyrolysis unit connected to a Hewlett Packard F and M Model 

 5750 temperature programed, dual column GLC. 



The connections were modified to allow the carrier gas to either bypass the 

 pyrolysis unit or sweep the pyrolysis products directly into the GLC unit. The volatile 

 pyrolysis products were resolved by using essentially the previously reported conditions 

 with minor modifications (Schwenker and Beck 1963) . 



The columns consisted of 12 feet of 1/4-inch diameter stainless steel packed with 

 Fluoropak 80, coated with 10 percent of 20M carbowax. The carrier gas was helium 

 flowing at the rate of 45 ml. /minute for the thermal conductivity measurements and 

 nitrogen flowing at the rate of 60 ml. /minute for flame ionization. The column 

 temperature was programed between 50° and 210° C. at the rate of 2° to 8° C. /minute. 

 The flame ionization detector was sufficiently sensitive so that a 20:1 splitter could 

 be used for collecting a major portion of the individual peaks for chemical identifica- 

 tions. The following methods were used for this purpose: (1) comparison of Revalues 

 and spiking with known compounds; (2) mass spectroscopy of the side stream collected in 

 a capillary tube cooled with liquid nitrogen; (3) u.v. spectroscopy of the collected 

 material; (4) bubbling of the side stream in a solution 2 ,4-dinitrophenylhydrazone 

 (DNPH) to form derivatives; (5) thin-layer chromatography (TLC) of the DNPH compounds 

 (Byrne, Gardiner, and Holmes 1966); (6) m.p. of the DNPH derivatives; (7) i.r. spectrum 

 of these materials; (8) Schiff's color test for aldehydes; (9) oxidation of an alcohol 

 with KMnO^ and TLC of the DNPH derivative of the resulting aldehyde; and (10) pH test 

 for acids. 



The GLC detectors were directly connected to a recorder and a Varian model 475 

 digital integrator. The integrator was calibrated by injecting known quantities of 

 each compound. Carbon dioxide was identified by the precipitation of BaC03 from a Ba 

 (OH) 2 solution and quantitatively analyzed by titration with oxalic acid. Water was 

 quantitatively analyzed with GLC using the thermal conductivity detector. The charred 

 residue left after 20 minutes at 600° C. was weighed in the original aluminum boats. 



A general consideration of the items listed in table 4 indicates two types of 

 products. One results from the fragmentation of the glucose units such as acetaldehyde, 

 glyoxal, l-hydroxy-2-propanone, and acrolein. The other is the type of material that 

 can be formed from the dehydration reactions such as water, char, and furan compounds. 

 Both of these reactions probably operate in untreated cellulose, although the degrada- 

 tion apparently dominates, especially at the elevated temperatures. The effect of 

 ZnCl2 treatment was to increase the amount of furan compounds, water, and char. The 

 NaOH treatment increased the 2 and 3 carbon carbonyl compounds as well as the char 

 (figs. 7 and 8) . 



12 



