Record Details

Sorption by detached organic films and its relation to filiform corrosion

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Field Value
Title Sorption by detached organic films and its relation to filiform corrosion
Names Kennedy, George Hunt (creator)
Slabaugh, W. H. (advisor)
Date Issued 1965-09-01 (iso8601)
Note Graduation date: 1966
Abstract The rate of interaction of carbon dioxide with eight detached organic films commonly used as coatings for metal surfaces was examined.
The films studied were lacquers of several different formulations
including oleoresinous, phenolic, vinyl, alkyd, epoxy, and
hydrocarbon types. The sorption was measured on a McBain type
gravimetric adsorption balance fitted with quartz helixes with an extension
sensitivity of about one mm. /mg. Rates of sorption were
measured at three temperatures, -45.3° C., -63.5° C. and -76.5° C.,
and at three pressures at each temperature, 461.0 torr, 326.5 torr
and 117.5 torr. Theoretical examination of the data lead to the conclusion
that the rate controlling mechanism was a diffusion process.
Sorption coefficients were calculated from the kinetic data and limiting
diffusion coefficients determined by extrapolation to zero CO₂ activity.
Values on the order of 10⁻¹² cm.²/sec. were obtained. From these
were calculated activation energies for the diffusion process, which
were compared to the calculated isosteric heats of sorption.
Oxygen sorption isotherms were attempted and no oxygen uptake
was detected. A few water vapor rate experiments were performed
for comparison with the CO₂ results. The rate of water vapor interaction
was found to be two to three orders of magnitude faster than
that for CO₂.
The eight films studied have been rated as to their relative resistance
to filiform corrosion growth. This relative resistance to
filiform corrosion was compared with the relative diffusion rate of
CO₂. A correlation is suggested, with the films showing faster CO₂
uptake also showing the most resistance. This is in agreement with
the observed effect that CO₂ in a corrosion test atmosphere inhibits
filiform corrosion growth.
Genre Thesis/Dissertation
Topic Corrosion and anti-corrosives
Identifier http://hdl.handle.net/1957/47502

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