Vinylidene cyanide homopolymerization

Spontaneous 1 1 copolymerization has been noted when sulfur dioxide was bubbled through bicycloheptene at —40°C. (88), when isobutylene was bubbled through methyl a-cyanoacrylate (54), when 1,3-dioxole was mixed with maleic anhydride (17), and when vinylidene cyanide was mixed with styrene (20), the latter reactions at room temperature. None of these monomers undergoes homopolymerization under the same experi-... 

Very recently the spontaneous, simultaneous homopolymerization of vinylidene cyanide and cyclic ethers including THF has been reported [105]. Polymerizations were initiated via a donor—acceptor complex but further investigation of the mechanism of initiation is continuing. It is still too early for kinetics to have been reported but they should be interesting when they do come. 

Tetracyanopropane was prepared in the first step from formaldehyde and mal-ononitrile as a compound possessing mobile hydrogen, in the presence of p-alanin as a base. Vinylidene cyanide (VCN) can be stored over P2O5. VCN is difficult to prepare and is highly reactive since a bit moisture enables its homopolymerization [23]. 

A similar initiation mechanism was demonstrated for the interaction of vinyl ethers with vinylidene cyanide, but in this case both an anionic and cationic homopolymerization took place in the same polymerization flask, an unusual event which was termed "cohabitory polymerization . ° ° Later, Dan Chting 16,119 able to fish some 2+2 cycloaddition products out of the polymer mixture obtained when the vinyl ethers reacted with vinylidene cyanide, thus lending support to a reaction mechanism in which the radical cation-radical anion pair could collapse to form the cyclobutane derivative or separate to initiate polymerization. The fact that a 1 1 alternating copolymer was obtained in the presence of a radical initiator supported the existence of a charge transfer complex. 

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