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Advanced hybrid fluoropolymers from the cycloaddition of aryl trifluorovinyl ethers

Posted on:2007-09-01Degree:Ph.DType:Thesis
University:Clemson UniversityCandidate:Ligon, S. Clark, JrFull Text:PDF
GTID:2441390005973373Subject:Chemistry
Abstract/Summary:
This dissertation discusses the synthesis of aryl trifluorovinyl ethers and their cycloaddition polymerization to give perfluorocyclobutyl (PFCB) polymers. To explore the stereochemistry of these polymers, simple monomfunctional aryl trifluorovinyl ethers were dimerized and the resultant cis and trans isomers were separated. Differences in structure help to improve understanding of the amorphous nature of the bulk PFCB polymeric material. To apply this knowledge, crown ether containing perfluorocyclobutyl (PFCB) polymers were synthesized for use in lithium ion battery applications. While poor solubility has hindered further development of these materials, slight modifications to structure may provide a solution. Also described is a fluorinated aryl vinyl ether and its attempted copolymerization with chlorotrifluoroethylene. While this copolymerization did not yield the desired materials, novel semifluorinated phenol precursors have been utilized in reactions with carboxylic acids to give polyesters and most recently with phosgene like species to give polycarbonates. Next, PFCB polymers were post functionalized with fluoroalkyl tethers to improve oleophobicity and hydrophobicity without decreasing thermal stability or optical clarity. In addition, various silica nanostructures were functionalized with aryl trifluorovinyl ethers. This includes the reaction of aryl silanes to give trifluorovinyl ether functional POSS and their polymerization to provide PFCB hybrid materials. Silane coupling agents were also used to functionalize colloidal silica and fumed silica nanoparticles. These procedures allow excellent dispersion of the silica nanoparticles throughout the fluoropolymer matrix. Finally, the reaction of aryl trifluorovinyl ether with nonfluorinated alkenes and alkynes was explored. In these reactions, the fluorinated olefin adds with the hydrocarbon olefin to give semifluorinated cyclobutanes (SFCB) and with the alkyne to give semifluorinated cyclobutene. The reaction with alkenes has been applied to bis functional acrylates and styrenics to grow SFCB polymers similar to the PFCB polymers. Also, the fluoroolefin was shown to add to multiple alkynes to give six membered ring adducts. These hetero cycloaddition reactions, which occur at temperatures well below those required to add the aryl trifluorovinyl ethers to themselves, provide multiple pathways for the development of new hybrid fluoropolymer materials.
Keywords/Search Tags:Aryl trifluorovinyl ethers, Polymers, PFCB, Cycloaddition, Hybrid, Give, Materials
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