Pyrolysis of cellulose in a vacuum
1956; US government; Volume: 56; Issue: 6 Linguagem: Inglês
10.6028/jres.056.045
ISSN2376-5305
AutoresS. L. Madorsky, V.E. Hart, Sidney Straus,
ResumoSamples of cotton , cotton h ydrocelJulose, and viscose rayo n, both by t hemselves an d impreg nat;ed with sod ium carbonate or sodium chloride, were p yl'Olyzed at 250 0 to 397 0 C in a lli g h vacuum.The volatile products were fractionated a nd t he fractio ns analyzed in th e m ass spectrometer a nd by inf rared absorpt ion.Th e volatile fraction s co nsisted mainly of CO, CO2, water, and levoglucosan (tar).The residue consisted main ly of carbon (cha r).Imp reg na t ion of the cellulosic m aterials with salt s caused a decrease in t he y ield of tar and an increase in t he yields of CO, CO" H 20 , a nd char.R ates of thermal degradation of the sam e materials were in vcstigated in the range 245 0 to 305 0 C by a loss-of-w eight m ethod, usin g a ver y sensitive t ungste n spring bala ncc enclosed in a vac uum.Plots of rates of loss of " 'eigh t versus percentage of loss of ' weight, in t h e case of pure cellulosic materials, p ass th rough maxima at a bout 13 to 23 percent loss of " 'eigh t, t he n drop graduall y to t he carb onization end point.In the case of sampl es impreg nated with sodium carbonate or sod ium chlorid e, t he initial ra tes of loss of weight are very hi gh , but drop rapidly to the carbon izatio n end p oi11 t .Th e activation energies o f thermal d egradation of t h e pure cellulosic mater ials are much greate r than t hose of t he sa me material s impregnated with sod ium carbo nate or sodium ch lor ide .1 'rhis work was performed as a part of the researcb project sponsored by the Office of Qua rtermas ter General , D epartment of t be Army, 2 'rbis paper was presented a t the 128th National Meeting of the American C hemi cal Society in Minneapolis, Minn., September 12 to 16, 1955.3 F ig ures in brackcsts indicate the literature references at t he end of this paper .
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