ABSTRACT
The versatility of cyclopolymerization of nonconjugated dienes is demonstrated. Compounds containing other polymerizable groupings are also shown to undergo cyclopolymerization. Among these are diynes, dialdehyes, diisocyanates, diepoxides, and dinitriles, as well as unsymmetrical monomers with respect to these functional groups. The effect of dilution on the shift of the carbonyl IR stretching band was smaller for dialdehydes than for monoaldehydes. In a similar type of cyclopolymerization, polymerization of 1,2-diisocyanates and 1,2,3-triisocyanates to cyclic polymers by an anionic mechanism have been described. The mechanism of the cyclopolymerization is considered and it was indicated that the initiation step occurred by attack of the catalyst anion on the carbon atom of one of the isocyanato groups, followed by cyclization and intermolecular reaction of the hybrid anion with another monomer molecule. The infrared spectra of the polyesters and their saponification products showed that the fumarate and the crotonate polymerized with the formation of lactone rings due to reaction between the double and triple bonds.
