865-54-3Relevant academic research and scientific papers
Original SF5-containing fluorinated copolymers based on vinylidene fluoride
Kostov,Ameduri,Sergeeva,Dolbier Jr.,Winter,Gard
, p. 8316 - 8326 (2008/02/02)
The radical co- and terpolymerization of fluorinated monomers bearing an SF5 group, XYC= CZSF5 (where X, Y, and Z represent either H or F atoms) with 1,1-difluoroethylene (vinylidene fiuoride, VDF or VF 2) and hexafluoropropene (HFP), is presented. Although these SF 5 monomers do not homopolymerize under radical initiation, they do copolymerize (and terpolymerize) in solution, in the presence of radical initiators with VDF (and with VDF and hexafluoropropylene (HFP)), hence leading to original copolymers bearing SF5 side groups. NMR characterizations and yields enabled one to compare the relative reactivities of F 2C=CFSF5, HFP, perfluoromethyl vinyl ether, and perfluoropropyl vinyl ether in the copolymerization of VDF with these fluoroolefins. The degree of fluorine substitution on the ethylenic unit of the SF5 monomers had an influence on their reactivity, on their relative incorporation in the copolymers, and on the molar masses of the resulting terpolymers - the higher the fluorine in the SF5 monomer, the higher molecular weight. Interestingly, the greater the degree of fluorine substitution of the SF5-containing monomer, the greater the yield of the reaction. The yield also increased as the amount of initiator was increased. The relative concentrations of the comonomers in each copolymer were assessed by 19F and 1H NMR spectroscopy. The thermal properties (thermal stability and glass transition temperature) of these resulting SF 5-containing fluoropolymers were also examined.
Sulfuranonium Ions, R-SF4+, Preparation, Evidence, and Stability
Wessel, Juergen,Kleemann, Gert,Seppelt, Konrad
, p. 2399 - 2407 (2007/10/02)
Sulfuranonium Ions of the type R-SF4+ are generated from R-SF5 by fluoride ion abstraction with SbF5.In spite of large variation of R (CH3, CH=CH2, CCH a. o.) none of the ions is stable at room temperature.The ions were identified by NMR met
