Synthesis of fluorine‐containing star‐shaped poly(vinyl ether)s via arm‐linking reactions in living cationic polymerization

Abstract

Various types of fluorine‐containing star‐shaped poly(vinyl ether)s were successfully synthesized by crosslinking reactions of living polymers based on living cationic polymerization. Star polymers with fluorinated arm chains were prepared by the reaction between a divinyl ether and living poly(vinyl ether)s with fluorine groups (C4F9, C6F13, and C8F17) at the side chain using cationogen/Et1.5AlCl1.5 in a fluorinated solvent (dichloropentafluoropropanes), giving star‐shaped fluorinated polymers in high yields with a relatively narrow molecular weight distribution. The concentration of living polymers for the crosslinking reaction and the molar feed ratio of a bifunctional vinyl ether to living polymers affected the yield and molecular weight of the star polymers. Star polymers with block arms were prepared by a linking reaction of living block copolymers of a fluorinated segment and a nonfluorinated segment. Heteroarm star‐shaped polymers containing two‐ or three‐arm species were synthesized using a mixture of different living polymer species for the reaction with a bifunctional vinyl ether. The obtained polymers underwent temperature‐induced solubility transitions in various organic solvents, and their concentrated solutions underwent sol–gel transitions, based on the solubility transition of a thermoresponsive fluorinated segment. Furthermore, a slight amount of fluorine groups were shown to be effective for physical gelation when those were located at the arm ends of a star polymer. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012

Synthesis of graft copolymers based on selective living cationic polymerization using an acetal group with a combination of Lewis acids

“…Graft copolymers consisting of fluorinated graft chains attached to a nonfluorinated backbone were also synthesized in a similar manner. Recently, we have demonstrated the synthesis of fluorine‐containing star‐shaped polymers and their unique solubility characteristics comparing to the corresponding block copolymers 31. Well‐defined fluorine‐containing graft copolymers would lead to another type of fluorinated polymers with branched structures.…”

The State of Fluoropolymers

“…Initial work in fluorine containing polymers focused on homo polymer synthesis with the primary focus on PTFE (12). This work has progressed towards the development of new polymerization methods and processes for new polymer networks such as controlled radical polymerizations (13) and cationic polymerizations (14). Initial work on copolymers focused on improving the solubility of the fluoropolymer (15) and has recently shifted towards the development of materials for advanced applications such as foul-resistant coatings (16) and lithography applications (17) …”

Recent advances in applications of vinyl ether monomers for precise synthesis of custom-tailored polymers

“…Treatment of the resulted polymers with different alkylimidazolium bases allowed preparation of corresponding uniform polymeric ionic liquids of narrow polydispersity (PDI 1.06-1.22) (Scheme 12). The same initiating systems were applied for the synthesis of fluorinated poly(VE)s from the parent fluorine-containing monomers [98,99]. The use of fluorinated solvents (hydrofluorocarbons, chlorocarbons, ethers and aromatics) appeared to be mandatory to provide solubility of the resulting materials.…”