University of Connecticut |
Polymer Program SeminarRecent Advances in the Controlled Radical Polymerization of Fluoroalkenes and Well-Architectured Fluoropolymers therefrom Thursday, October 12,2006 2:00 PM , IMS Room 20 After reviewing the properties and applications of fluoropolymers [1] and the different methods of Controlled Radical Polymerization (CRP) including those successfully adapted to fluoromonomers, two main strategies based on the “transfer” were adopted: one involving xanthates as the chain transfer agents (CTA) and iodine transfer polymerization (ITP) of vinylidene fluoride (VDF) in the presence of C6F13-CH2CF2-I (Figure 1) and HCF2-CF2CH2-I as CTAs [2]. Evidence of the CRP of VDF (or VDF / hexafluoropropene) was found. Then, the syntheses of well-defined fluoropolymers were reported. Block copolymers were produced from ATRP or ITP of styrenic derivatives with CCl3-F-Block or (I-)-PVDF-I [3], respectively. Then, original PVDF-g-PS graft copolymers were also obtained from bromine-containing random F-copolymers in a living behavior. Industrial applications from CRP of fluoroalkenes (e.g., thermoplastic elastomers, fuel cell membranes, emulsifiers for polymers blends) will illustrate this presentation. References 1) Ameduri B.; Boutevin B. Well-Architectured Fluoropolymers: Fluorotelomers, Telechelics, Alternating, Block and Graft copolymers, Elsevier, Amsterdam, 2004. 2) Boyer C., Valade D., Sauguet L., Ameduri, B.; Boutevin, B.; Macromolecules, 2005, 38, 10353-10362. 3) Sauguet L., Boyer C., Ameduri B.; Boutevin B., submitted to Macromolecules. Figure 1: Molar Masses versus vinylidene fluoride conversion for the Iodine transfer Polymerization (ITP) of VDF in the presence of chain transfer agents: C6F13I (♦) and C6F13CH2CF2I (*) at 75 °C. (the dotted line represents the theoretical straight line)
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