Catalytic Synthesis and Characterization of Biodegradable ...

Preface
Biodegradable polyesters have attracted great attentions to be developed as the environment
friendly materials and biomedical materials due to their excellent biodegradable and biocompatible
properties. Two main tasks, i.e. controlled synthesis and functionalization of polyesters, have
emerged in order to obtain the polyesters with tunable properties for biomedical applications. Great
advances have been achieved by virtue of the recent progresses on the controlled living
polymerizations and polyesters functionalities. However, efforts still remained on the synthesis of
polyesters with more controllable structures and smart properties.
In this thesis, the author has provided two strategies to synthesize biodegradable polyesters by
using a series of newly synthesized cobalt-Schiff-base complexes. Controlled synthesis of
polylactide (PLA)-analogues polyesters are expected based on the studies on the catalyst’s activity
and polymerization mechanism. Moreover, functionality of PLA by incorporating with stable
TEMPO radical-substituted polymers has also been synthesized and investigated for the biomedical
applications in tissue engineering and bioimaing. Chapter 1 reviews on biodegradable polyesters,
electro-active polymers and radical polymers, plus their applications in biomedical fields. Chapter 2
describes the synthesis of a series of cobalt-Schiff-base catalysts for alternative copolymerization of
racemic propylene oxide and carbon dioxide. Chapter 3 describes the application of
cobalt-Schiff-base catalysts in ring-opening polymerization of lactic acid-O-NCA (LCA) monomer
to synthesize PLA. Chapter 4 describes the synthesis and bio-valuations of TEMPO-contained
PLA-PTAm random copolymers. Chapter 5 deals with the controlled synthesis of block copolymers
bearing radical polymer segments by RAFT polymerization method and their biomedical
applications. Chapter 6 deals with the synthesis of amphphilic di- and tri-block copolymers
containing stable TEMPO radical segment and their untiliting as EPR bioimaging probes. Chapter 7
concludes this thesis and proposes the perspective of the controlled synthesis, functionalization and
biomedical applications of polyesters.
III
Xiuli Zhuang