Identifier

etd-07162007-132432

Degree

Doctor of Philosophy (PhD)

Department

Renewable Natural Resources

Document Type

Dissertation

Abstract

Wood liquefaction was conducted using phenol as a reagent solvent with oxalic acid as a catalyst. A series of studies were done on liquefied wood, liquefied wood residues, novolac-type liquefied wood resins, and bio-composites fabricated from liquefied wood resin. The results of the liquefied wood residue characterization revealed that the liquefaction reactions conducted in different reaction vessels underwent different liquefaction mechanisms. The crystallinity indexes of the liquefied wood residues were higher than that of the original wood, indicating that the amorphous lignin was the most susceptible component in wood to the liquefaction reaction. Fe2+ and Fe3+ ions were found to have catalytic effects during liquefaction reaction. The cure kinetic study of two typical liquefied wood resins (LWR) showed that the activation energies of liquefied wood resin were higher than conventional phenolic resins and close to that of a lignin-phenol-formaldehyde resin from another study. It was found that LWR followed an autocatalytic cure mechanism. Two kinetic models were proposed for LWR based on the isothermal differential scanning calorimetry (DSC) methods. The flexural strengths of the composites were comparable to that of similar products reported by other researchers, indicating that the liquefied wood resin and liquefied wood residue from a weak-acid-catalyzed liquefaction could be successfully applied to molded bio-composite products as a substitute for conventional novolac resin.

Date

2007

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Todd F Shupe

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