Supramolecular Miktoarm Star Polymer Based On Host-Guest Interaction

ABC miktoarm star polymers have attracted great attention in recentyears for their interesting morphologies and promising applications.However, the construction of these asymmetric star polymers is still a greatchallenge. We designed and fabricated a novel supramolecular ABCmiktoarm star-shaped terpolymer via host-guest interaction. By replacingone of the covalent connections between polymer segment and joint pointwith the noncovalent recognition, the synthetic route was simplified.Moreover, this novel supramolecular ABC miktoarm star terpolymerexhibited the ability to assemble and disassemble. This dissertationincludes the following two parts:1. Supramolecular ABC miktoarm star terpolymer was synthesized viathe molecular recognition between β-cyclodextrin-(β-CD-)based host andadamantane-(AD-)modified guest. In the first step, β-CD with twodifferent functional groups was prepared, which was further used toconstruct a diblock copolymer as the host part via “click” reaction withalkynyl-poly(ethylene glycol)(alkynyl-PEG) and atom transfer radicalpolymerization (ATRP) of dimethylaminoethyl methacrylate (DMAEMA)monomer. On the other hand, the AD-modified polymer as the guest partwas obtained by ATRP of methyl methacrylate (MMA). The polymerichost and guest formed the final star-shaped ABC miktoarm terpolymer viaa simple mixing procedure. The prepared amphiphilic ABC miktoarmterpolymer could self-assemble into micelles in aqueous solution. Thetransition of this supramolecular ABC miktoarm star terpolymer from assembly to disassembly could be readily controlled by adding thecompetitive host or guest.2. Supramolecular ABC miktoarm star terpolymer with lightresponsiveness was synthesized via the molecular recognition betweenβ-CD-based host and azobenzene-(AZO-)modified guest. In the first step,the AZO-modified polymeric guest was obtained by ATRP of methylmethacrylate (MMA). MPEG-β-CD-PDMAEMA served as the host. Thepolymeric host and guest formed a star-shaped ABC miktoarm terpolymervia a simple mixing procedure. The prepared amphiphilic ABC miktoarmterpolymer could self-assemble into micelles in aqueous solution, and thetransition from assembly to disassembly could be realized by UVirradiation.