Cyclopolymerization of unconjugated

It is well known that, in the cyclopolymerization of unconjugated dienes which can form 5- and 6-menbered ring structural units, these units often largely prevail over the linear ones, that is the units deriving from monomer molecules which have contributed to the polymer chain growth with only one of their unsaturations. To account for this fact, several hypotheses have been suggested, which will be reviewed and discussed in the present paper. 

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