Date Available
5-31-2017
Year of Publication
2016
Degree Name
Doctor of Philosophy (PhD)
Document Type
Doctoral Dissertation
College
Arts and Sciences
Department/School/Program
Chemistry
First Advisor
Dr. Mark Crocker
Second Advisor
Dr. John Selegue
Abstract
Lignin is one of the most abundant and underutilized biopolymers on earth. Primarily composed on three monolignol units (sinapyl, coniferyl, and p-coumaryl alcohol), lignin is formed through a radical pathway resulting in an assortment of linkages, of which the β-O-4 linkage is the most prevalent (up to 60% in some hardwood species). In planta, lignin plays an important role in water transport and in protecting plants from chemical and biological attack. Traditional attempts to depolymerize lignin have focused on the cleavage of β-O-4 linkages via thermal or reductive routes. However these pathways lead to low-value, unstable product mixtures. Moreover, typical product yields are low and the highly corrosive reaction medium results in added expense. More recently, catalytic oxidations have been studied as a viable means to lignin utilization. The present work will review the state-of-the-art of lignin oxidations, and focus on stoichiometric and catalytic attempts to oxidize lignin and lignin model compounds in order achieve selective stepwise depolymerization of lignin. Specifically, activated dimethyl sulfoxides and LDH catalysts were evaluated for lignin and/or lignin model compound oxidations leading, in some cases, to unexpected products.
Digital Object Identifier (DOI)
http://dx.doi.org/10.13023/ETD.2016.225
Recommended Citation
Mobley, Justin K., "TOWARDS CATALYTIC OXIDATIVE DEPOLYMERIZATION OF LIGNIN" (2016). Theses and Dissertations--Chemistry. 59.
https://uknowledge.uky.edu/chemistry_etds/59
