Polymerization of novel trifluorovinyl ethers: Insight into the mechanisms of termination and chain transfer

Abstract

New trifluorovinyl ether polymers were synthesized with the view toward overcoming the high chemical and thermal stabilities commonly associated with flu- oropolymers. Trifluorovinyl ether copolymers, with fluorinated pendant groups, have previously been prepared to overcome limitations in processibility. To further enhance solubility in common organic solvents and to improve processibility, we prepared three new trifluorovinyl ether monomers, having hydrocarbon ether pendant groups, for polymerization: 1-(2-(2-ethoxy ethoxy)ethoxy)-1,2,2-trifluoroethene (Et-TFVE), 1-(2-(2- t-butoxy ethoxy)ethoxy)-1,2,2-trifluoroethene (t-Bu-TFVE), and 1-(2-phenoxy ethoxy)- 1,2,2-trifluoroethene (Ph-TFVE). Homopolymers of these three monomers were pre- pared by aqueous emulsion polymerization with the use of a redox initiator. Poly(Et- TFVE) and poly(Ph-TFVE) were prepared with a range of molar masses, the highest of which had weight average molar masses of 33,800 g mol 21 and 59,000 g mol 21 , respectively. As a result of monomer reactivity and structure, the polymerization mechanism was complicated, resulting in b-scission termination/chain transfer for all three polymers and hydrogen abstraction chain transfer for poly(Et-TFVE) and poly(t- Bu-TFVE). To the best of our knowledge, this is the first example of hydrogen abstrac- tion from the pendant group of the trifluorovinyl ether itself. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3301-3308, 1999