Synthesis Of Hydrophilic Polymeric Nanoparticles Based On Bergman Cyclization

Polymer nanoparticles with controlled structural characteristics have drawn considerable attention in recent years. In nanomedicinal research, especially drug delivery and imaging, particles with controlled size and tailored arrangement of functional groups are required. Intramolecular chain collapse is an efficient way for the fabrication of well-defined polymer nanoparticles. With this technique, it is possible to produce particles below20nm with a wide variety of chemical compositions and functionalities. Bergman cyclization is the process to form an aromatic1,4-diradical system from enediynes, which can lead to DNA cleavage via H-atom abstraction.,The synthesis of enediynes, as well as the study on their antitumor and antibiotic activites, has becoming a hot research topic nowadays. However, the application of Bergman cycloaromatization in polymer chemistry and materials science was less tried.In this thesis, a series of poly(benzyl acrylate)(PBzA) with different molecular weight and two kind of enediynes were synthesized by single-electron transfer living radical polymerization(SET-LRP) technique and Pd catalytic C-C bond coupling reaction, respectively. After the PBzA being functionalied by enediynes, the linear polymers were fabricated into nanoparticles via Bergman reaction mediated intramolecular chain collapse under ultra-dilute condition. Subsequent formation of polyacrylic acid (PAA) nanoparticles was achieved by deprotection of the benzyl ester groups through hydrogenolysis. With these PAA nanoparticles as nanoreactors ZnS QDs and CdS QDs were fabricated in menthol at room temperature. The linear polymer and nanoparticles were characterized with NMR, GPC, IR and AFM. The QDs were characterized by UV, PL and HR-TEM.