OEG-based Thermoresponsive Dendritic Macromolecules

Thermoresponsive polymers have drawn considerable interest and are beinginvestigated for promising applications in areas including biomaterials, drug carriesand biosensors. Therefore, to afford novel polymers with attractive and tunablethermoresponsive properties and study the structural effects will not only providenew ideas for theoretical researches but also may pave the way for design andapplications of novel smart materials. Herein, a novel kind of OEG-basedamphiphilic dendritic macromonomers and their corresponding dendronizedpolymers were synthesized (Figure A), and their thermoresponsive propertiesinvestigated. The detailed thesis includes the following three parts:(1) Two dendritic macromonomers, which were constructed with a secondlysine-based dendron as the interior (hydrophobic part) and oligoethylene glycolOEG chains or dendrons as the periphery (hydrophilic part), were designed andsynthesized, respectively.(2) The dendronized polymers were prepared by macromonomer routes and theirstructures and molecular weights were characterized by1H NMR and GPCmeasurements. Circular dichroism spectroscopy and AFM measurements wereused to investigate the secondary structures and morphologies of the polymers,respectively.(3) Their thermoresponsive behavior were investigated by temperature dependent1HNMR, UV/Vis and DLS.The results showed that topology, OEG density in the periphery and switchableamphiphilicity of these dendritic macromolecules show significantly effects on theirthermoresponsiveness. These findings enrich understanding of structure effects onthermoresponsive properties of macromolecules, which may also find broad interestin developing various smart polymer materials. Figure A Cartoon representation of amphihilic dendritic macromolecules and itstypical thermoresponsive behavior in aqueous solution...