STUDIES OF THE ALTERNATING COPOLYMERIZATION OF VINYL ETHERS WITH CHLOROTRIFLUOROETHYLENE

The copolymerization of chlorotrifluoroethylene (CTFE) with several vinyl ethers (VE) (hydroxyethyl vinyl ether, glycidyl vinyl ether, and chloroethyl vinyl ether) was studied. CTFE is an acceptor monomer (e approximately +2), whereas the VE's are highly donor ones (e approximately -2), so they can copolymerize and lead to alternating copolymers. Such a behavior was shown by determining the composition of the copolymer at the beginning of the reaction, and we proved by F-19 NMR of CTFE that the equilibrium constant of the charge-transfer complex formation (CTC) is high (K = 1.4). Then, the structure of the copolymer was investigated by performing the cotelomerization of CTFE and a VE with a fluorinated thiol (C6F13C2H4SH). This reaction produced both the monoadducts and the dimer structure (opposite to that expected from the CTC) which are in contradiction with the polymerization by propagation of the transfer complex. Thus a polymerization of free monomers is proposed, and the alternating behavior of the copolymer comes from the great difference in polarity between these two kinds of monomers.