Study On The Synthesis Of Hydroxycucurbit[6] Uril-based Polymers And Their Properties

Cucurbit[n]uril(CB[n]),a rigid barrel-shaped macrocyclic cavitand,is composed of six glycoluril units and provides highly selective interaction sites with various organic compounds via ion-dipole,H-bonding,and hydrophobic interactions.Introduction of CB[n]to polymers has generated considerable interest due to the unique properties of these macromolecules.An apparent advantage of CB[n]anchored polymers is the appearance of CB[n]cavity on the polymer backbone,which can construct noncovalently connected polymeric architectures by supramolecular complexation.Moreover,the incorporation of CB[n]into polymeric systems can influence the self-assembly behaviors and the rheological performance of the polymers.All these fascinating properties of CB[n]anchored polymers would be useful in supramolecular chemistry,analytical studies,separation technology,macromolecular machines,smart materials and pharmaceutical applications.However,the covalent linkage of between CB[n]and polymer chains can not be performed easily,and thus their applications are limited.In order to bond CB[n]into polymer backbone,reactive functional groups,such as double bounds,must be appended on the CB[n]surface.Our efforts have been focused on developing the method for synthesis of CB[n]anchored polymers.In this paper,hydroxylcucurbit[6]uril was used to construct the CB[6]-based polymers through the non-covalent bond interaction,free radical polymerization and gradual polymerization.The properties of CB[6]-based polymers was also studied.(1)This paper summarizes the history,synthesis and recognition properties of CB[n]and the synthesis of CB[n]derivatives,and summarizes the application of CB[n]in the design of catalytic and stimulated responsive switches,and CB[n]as the main monomer in biomedical and host-guest polymers.(2)We synthesized the polyethylene glycol-polyvinylpyrrolidone amphiphilic water-based block copolymer(PEG-b-PVP)by atom transfer radical polymerization(ATRP).The copolymer was mixed with PerhydroxyCB[6]((HO)12-CB).The SEM and DLS demonstrate that the aggregates are nanoparticles and have a pH-responsive function.When the pH is below 6 or above 13,the aggregates are dispersed,and the the solution became clear;the pH was between 6 and 13,and the aggregates were reassembled and the solution became turbid.This indicates that CB[6]is introduced into the polymer system and does affect the self-assembly behavior and rheology of the polymer,which can regulate the behavior of the polymer.(3)In this chapter,(HO)n-CB[6],which is relatively well soluble in DMSO,was prepared by changing the amount of hydrogen peroxide and the reaction time according to the related literature.CB[6]based methacrylate was prepared by the reaction between(HO)n-CB[6]and methacryloyl chloride,and then the thermo-sensitive and pH sensitive functional polymer based on CB[6]was successfully synthesized by copolymerization of CB[6]based methacrylate with acrylic acid.The copolymer solution was clarified at pH<2.59 and pH>12,and the solution was cloudy when the solution pH was near neutral.In the similar method,six double bonds was introduce to CB[6]by the reaction of(HO)12-CB[6]with methacryloyl chloride.The three-dimensional polymer was obtained by the free radical polymerization of CB[6]monomer.The results of SEM shows that morphology the three-dimensional polymer was rod-shaped polymer.(4)Finally,we use the(HO)n-CB[6]as raw materials to synthesize three CB[6]-based polymers by stepwise polymerization,which are CB[6]-alkane polyether,CB[6]aromatic hydrocarbon polyether and CB[6]-HDI(hexamethylene diisocyanate)polyurethane.The results were confirmed by 1H-NMR and IR.These three polymers based on CB[6]will have potential applications in molecularly imprinted polymers.