Biomedical Polymers for Micelles and Nanoparticles
Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
A number of amphiphilic and resorbable block copolymers belonging to the two families of Polyvinyl pyrrolidone-Polycaprolactone (PVP-PCL) and Poly lactide-Polyvinyl pyrrolidone (PLA-PVP) were synthesized. e-caprolactone and hydroxyl end-functionalized PVP chains were successfully synthesized by free radical polymerization of vinyl pyrrolidone monomer using e-caprolactone and isopropoxyethanol as solvent and chain transfer agent, respectively. The assigned end-functionalities were used to synthesize PCL block using two techniques of anionic ring opening polymerization and ring opening polymerization (ROP). Hydroxyl end-functionalized PLA of varying molecular weight was synthesized using ring opening polymerization of L-Lactide. This was followed by the introduction of vinyl groups into the PLA chains using acrylation (end-capping). The vinyl end-groups were used to facilitate the attachment of the PVP block using free radical polymerization. The average molecular weight, PDI and chemical structure of the homopolymers and copolymers were studied using Size Exclusion Chromatography (SEC) and 1H-NMR analysis. The molecular weight studies of the PVP and PLA homopolymers complied with the theoretical values of the molecular weights, however, some deviations from the desired molecular weights and PDI values were also observed in both cases. PVP-PCL copolymer was well synthesized and a monomer ratio of 37.88% for VP was achieved. Acrylation of the PLA homopolymers showed a maximum end-groups conversion of 50%, which efficiently contributed to the polymerization of PVP block in PLA-PVP copolymer. The synthesized amphiphilic copolymers successfully formed micellar aggregates in dilute aqueous solutions with identifiable CMC values. Furthermore, nanoparticles were fabricated from PVP-PCL by critical CO2 extraction.
Place, publisher, year, edition, pages
amphiphilic, copolymer, polymeric micelle, nanoparticle, PLA, PCL
Engineering and Technology
IdentifiersURN: urn:nbn:se:kth:diva-145858OAI: oai:DiVA.org:kth-145858DiVA: diva2:720734