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Document Type

Thesis - University Access Only

Award Date

2015

Degree Name

Master of Science (MS)

Department

Chemistry and Biochemistry

First Advisor

Douglas E. Raynie

Abstract

Lignin is a very complex heterogeneous biopolymer present in the secondary cell wall of vascular plants. Lignin is biologically significant for plants and also a potential alternate source of value-added chemicals and renewable energy. In spite of its importance, complete understanding of the lignin structure is not known. Understanding the lignin structure and macromolecular characteristics is significant for proper utilization, such as in depolymerization to value-added aromatic compounds. In our research, thermal properties and degradation behavior of the two commercial lignins (Kraft pine lignin (Indulin AT, Mead Westvaco) and Alkali lignin (Sigma-Aldrich)) were investigated using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Structural characterization was performed using attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, proton nuclear magnetic resonance spectroscopy (1H-NMR), and elemental analysis. Cupric oxide oxidation was used to selectively degrade the lignin into its monomers (H/G/S-moieties). The results suggested that these selected lignins were structurally similar and mainly composed of G-type monomers. In addition, lignin samples were reacted using a high temperature hydrotreatment with subcritical and carbon-supported metal oxide (CoO, LaO, MoO) catalysts. Seventeen methoxyphenols were observed in the product mixture. xv MoO was found to give the best performance among the catalysts, in terms of the number of methoxyphenol compounds produced and their relative amount.

Library of Congress Subject Headings

Lignin
Lignin--Thermal properties

Description

Includes bibliographical references (pages 90-92)

Format

application/pdf

Number of Pages

118

Publisher

South Dakota State University

Rights

In Copyright - Educational Use Permitted
http://rightsstatements.org/vocab/InC-EDU/1.0/

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