Accession Number:

AD0260253

Title:

OXIDATION OF PYROLYTIC GRAPHITE BETWEEN 1250 F AND 1850 F

Descriptive Note:

Corporate Author:

WATERTOWN ARSENAL LABS MASS

Personal Author(s):

Report Date:

1961-05-01

Pagination or Media Count:

1.0

Abstract:

The oxidation of pyrolytic graphite was studied as a function of time and temperature. Pyrolytic graphite does not oxidize as rapidly as commercial graphite at temperatures below 1450 F but approaches that of commercial graphite at 1550 F. Oxidation of pyrolytic graphite proceeds preferentially in the c-direction contrary to expectation. The break in the Arrhenium plot for pyrolytic graphite occurring at 1550 F may beATTRIBUTED TO THE CHANGE IN CONTROL MECHANISM FROM CHEMICAL REACTIVITY TO DIFFUSION CONTROL. An activation energy of 37,180 calories per mol was calculated for a commercial graphite. The activation energy calculated for pyrolytic graphite was 23,350 calories per mol. The lower activation energy for pyrolytic graphite is associated with a lower reaction rate. This anomalous behavior is attributed to its lower porosity since a less porous material exposes a smaller surface area for molecular collisions. Author

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Distribution Statement:

APPROVED FOR PUBLIC RELEASE