Cyclopolymerization divinyl ether

Geometric considerations would seem to dictate that 1,4- and 1,5-dicncs should not undergo cyclopolymerization readily. However, in the case of 1,4-dienes, a 5-hexenyl system is formed after one propagation step. Cyclization via 1,5-backbiling generates a second 5-hexenyl system. Homopolymerization of divinyl ether (22) is thought to involve such a bicyclization. The polymer contains a mixture of structures including that formed by the pathway shown in Scheme 4.18. 

Cyclopolymerizations yielding more complex ring structures have also been reported [Butler, 19896, 1989]. For example, 1,4-dienes such as divinyl ether yield uncrosslinked products with little or no unsaturation and possessing different bicylic structures. The formation of one of the bicyclic structures is shown in Eq. 6-107 [Tsukino and Kunitake, 1979]. 

Cyclocopolymerization is cyclopolymerization of a pair of monomers [Butler, 2000]. An example is the generation of pyran rings by copolymerization between maleic anhydride and the two double bonds of divinyl ether ... 

Intermolecular cyclization reactions are also possible, e.g., in the cyclopolymerization of divinyl ether with maleic anhydride ... 

Further examples of cyclopolymerization have been cited. Divinyl ether gives polymers containing bicyclic units. The polymerizations of 1,4-divinylbenzene and 1,3,5-trivinylbcnzene have been investigated. Ring-opening radical polymerizations for derivatives of vinyl cyclopropane have been described... 

Divinyl ether monomers undergo cyclopolymerization under free-radical as well as cationic conditions. If the polymerizations are carried to high conversion (>30 to 35%), gelation occurs. However, the soluble polymers that are produced at high dilution and low conversion often have rather complex backbone structures. For example, the polymerization of divinyl ether proceeds to give a polymer that incorporates tetrahydrofuran, vinyloxy, and dioxabicyclo[3.3.0]octane units [137,138] ... 

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