Synthesis and assembly of biodegradable/ compatiblegraft copolymers for biomedical applications
Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
The synthesis and characterization of nanostructured block copolymers is described.Block copolymers were grafted onto a backbone polymer that consists of themonomer MTC-BuOBn. The block copolymers have a part consisting of PTMC(trimethylene carbonate) and a part consisting of PLLA. The purpose with this thesiswork was to demonstrate the efficacy of block polymer formation. TMC serves as amodel for other cyclic carbonates which can be readily functionalized.Thenanostructure was synthesized using ring opening polymerization with anorganocatalyst under mild conditions. The conversion and the solution conformationwere monitored by 1H NMR spectroscopy. The molecular weight (Mn) andPolydispesity Index (PDI) were obtained by gel permeation chromatography (GPC). Iorder to confirm the formation of the nanostuctures, the individual molecules weredeposited on silicon wafers and imaged by atomic force microscopy (AFM).
The AFM images show that the backbone with blocks consisting of with PLLA, PTMC and PLLA and PTMCrespectively form elongated structures. The phase transition behavior, e.g. glass transitiontemperature, Tg,crystallization temperature Tc and melting temperature Tm, were characterized bydifferential scanning calorimetry (DSC). The thermal analyses results indicate that the PLLA-and the PTMC-grafted backbones are semicrystalline while the backbone grafted with both PLLA andPTMC is amorphous. While the grafted backbone forms an elongated structure, an analogouPLLA-grafted dendrimer forms a spherical structure, as expected.
In sum, we have shown that we can control macromolecule shape through chemistry
Place, publisher, year, edition, pages
UPTEC K, ISSN 1650-8297
IdentifiersURN: urn:nbn:se:uu:diva-174804OAI: oai:DiVA.org:uu-174804DiVA: diva2:528918
Master Programme in Chemical Engineering
Hedrick, James LCoady, Daniel J
Bowden, TimWestin, Gunnar