| Abstract: | Ring-opening polymerizations of cyclobutane adducts of tetracyanoethylene (TCNE) and vinyl ethers (VE) or p-methoxystyrene with tertiary amines are described. The polymerization of the cyclobutane adduct 1a of TCNE and ethyl vinyl ether (EVE) was carried out with 10 mol % of triethylamine in acetonitrile at ambient temperature to afford the alternating copolymer of TCNE and EVE with high molecular weight in good yield under various conditions. Under the optimum condition, the cyclobutane adducts of TCNE and a variety of VEs such as n-butyl vinyl ether, isobutyl vinyl ether, 2,3-dihydrofuran, and 3,4-dihydro-2H-pyran were polymerized to yield similar polymers. Although the cyclobutane adduct 4 of TCNE and p-methoxystyrene did not polymerize under these conditions, the treatment of 4 with 1,8-diazabicyclo5.4.0]undec-7-ene (DBU) in acetonitrile at 60°C gave the polymer. On the basis of the fact that the polymer molecular weight increased rapidly at the initial stage and slowly even after the consumption of all of monomers, we propose that the tertiary amine initiates the chain anionic polymerization of the cyclobutane adduct to afford an ammonium macrozwitterion 3 , which is subjected to the intermolecular nucleophilic substitution with each other in a step polymerization manner. © 1995 John Wiley & Sons, Inc. |
