Design,Synthesis And Functionalization Of Perfluorocyclobutyl Aryl Ether Polymers Bearing Phenolic Hydroxyl Groups

Perfluorocyclobutyl(PFCB)aryl ether polymers are a new class of semi-fluorinated polymers,which are promising for applications in areas such as coatings,luminescent materials,fuel cell membranes,space materials and optical materials,due to their unique properties including low dielectric constant,high thermal/oxidative/chemical stability,excellent optical properties and good processability.PFCB aryl ether polymers are commonly synthesized by thermal(2?+2?)cyclopolymerization of aryl trifluorovinyl ether(TFVE)monomers,while aryl TFVE monomers are typically prepared from commercially available phenols via the fluoroalkylation reaction followed by zinc-mediated elimination reaction.However,the development of PFCB aryl ether polymers has been hindered,since the limitation of commercially available phenols and some functional groups are not stable under the conditions for the preparation and polymerization process of aryl TFVE monomers.To explore a new strategy for the preparation of PFCB aryl ether polymers,in this thesis,a class of versatile reactive polymer precursor:PFCB aryl ether polymers bearing phenolic hydroxyl groups(PFCB-OH-xx),was designed and synthesized.Preliminary investigation of the functionalization of PFCB-OH-xx was conducted,and three types of novel PFCB aryl ether polymers were obtained.This thesis mainly includes the following two parts:1.Synthesis and thermal properties of novel PFCB aryl ether polymers containing sulfonated flexible side chainsA new aryl TFVE monomer with a methoxy group(MOTFVB)was designed,and synthesized from 2-methoxyhydroquinone.Then PFCB-OH-xx with adjustable phenolic hydroxyl contents was prepared via the thermal polymerization of MOTFVB followed by demethylated reaction.Finally,a serial of novel PFCB aryl ether polymers containing sulfonated flexible side chains(S-PFCB-xx)were prepared via a nucleophilic ring-opening reaction between phenolic hydroxyl groups and 1,3-propanesultone.The structures of the monomers and polymers were confirmed by 1H NMR,19F NMR and FT-IR spectra.DSC and TGA data show that the polymers have good thermal properties.Furthermore,the polymers exhibit good solubility in common organic solvent.2.Synthesis and thermal properties of novel PFCB aryl ether polymers containing allyl/propargyl groupsNovel PFCB aryl ether polymers containing allyl/propargyl groups(PFCB-O-Pbe-xx and PFCB-O-Pby-xx)were successfully synthesized via a nucleophilic substitution reaction between phenolic hydroxyl groups and 3-bromopropylene or 3-bromopropyne.The structures of the polymers were confirmed by 1H NMR,19F NMR and FT-IR spectra.The thermal crosslinking process of PFCB-O-Pbe-xx and PFCB-O-Pby-xx was investigated by DSC.DSC and TGA data show that the resulted polymers have good thermal properties.Furthermore,the polymers exhibit good solubility in common organic solvent.