Cycloolefins homopolymerization

Natta, G Dall Asta, G Bassi, I. W. CareUa, G. Stereospecific ring cleavage homopolymerization of cycloolefins and structural examination of the resulting homologous series of linear crystalline fran -polyaUcenamers. Makromol. Chem. 1966, 91, 87-106. 

While the copolymerization of norbornene and ethylene by vanadium and titanium catalysts had been investigated in the 1970s, it was not until the invention of metallocene/MAO catalysts and their application to the homopolymerization of norbornene and other cycloolefins by Kaminsky et ai.8,15,19 that the use of early transition metal catalysts for the addition polymerization of norbornene drew new attention. Nevertheless, the industrial relevance of E/NB copolymers, and the nature of the homopolymers, described in the first reports as insoluble in organic solvents, crystalline, and extremely high melting, focused further investigations on copolymers rather than on norbornene homopolymers. 

Late transition metal catalysts, which are more tolerant of polar functional groups than early transition metal catalysts, are most suitable and highly active for norbomene homopolymerizations or copolymerization with other cycloolefins. A range of tailor-made homo-, co-, and terpolymers based on substituted norbomenes for applications in electronic materials are produced and commercialized, but they need further development to be efficiently used in olefin-cycloolefin copolymerizations. 

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