Preparation And Self-assembly Of β-cyclodextrin-based Amphiphilic Supramolecular Polymers

In this thesis, the research progress on supramolecular chemistry, cyclodextrins, "click" chemistry, atom transfer radical polymerization (ATRP) and the self-assembly behaviors of polymers in selective solvents was summarized in detail. By the combination of "ATRP", "click"chemistry and the host-guest inclusion betweenβ-cyclodextrin (β-CD) and the adamantly group (AD), we synthesized the dumbbell-lik supramolecular amphiphilic copolymers with a long polystyrene (PS) mid block and short poly (ethylene oxide) (PEO) arms at both ends, then their self-assembly behavior in selective solvents was investigated. The specific contents of this thesis are described as follows:(1) The first step involved the reaction of primary hydroxyl groups in theβ-cyclodextrin with the iodine elemental (I2) and sodium azide(NaN3) to obtain the per-azido-β-cyclodextrin.The second step involved the reaction of triazo in the per-azido-β-cyclodextrin (β-CD-N3) with terminal alkynyl of polyethylene glycol single methyl ether (PEO-Alk) to formβ-cyclodextrin modified with seven PEO arms.(2) Hydrophobic polymers were successfully synthesized by a two-step approach. In the first step, azido-polystyrene was obtained by applying homemade two-way initiator and CuBr/bpy as catalyst. And then the reaction between the as-prepared azido-polystyrene and alkynyl-based adamantine was carried out, forming a series of adamantyl-terminated polystyrene with different molecular weights.(3)The dumbbelll-like supramolecular amphiphilic copolymer (PEO7-β-CD-AD-PS-AD-β-CD-PEO7) were constructed through the host-guest inclusion betweenβ-cyclodextrin (β-CD) and the adamantyl group (AD).(4) The self-assembly behavior of the amphiphilic copolymers (PEO7-β-CD-AD-PS-AD-β-CD-PEO7) was investigated in water, and the bowl-shaped micelles were observed. Further studies indicate that the self-assembly process of the co-polymers are controlled by several different factors, such as the initial concentration of the co-polymers, the proportion of hydrophilic and hydrophobic chain segments. Furthermore, all these polymers were characterized by FT-IR, Gel Permeation Chromatography (GPC) and NMR, and the morphology from the self-assembly of the co-polymers were studied by TEM.