Polymerizations initiated by thermally activated donor-acceptor complexes

2 Polymerization initiated by thermally activated donor-acceptor complexes 

Complexes of monomers with acceptors can initiate polymerizations of the respective monomers even without photoexcitation. The properties of DA complexes and the conditions of the thermal activation are determined by the type of donor (monomer), acceptor, and solvent [300,303]. Ion radicals from the monomer, dipolar intermediates (zwitterions), as well as the relatively 

Many specific examples of reaction type (81) have been described, and iheir number has been increasing. In many of these, vinyl carbazole is the donor. Other monomers can also react in a similar way [304]. 

Hall and co-wokers [305] formulated a general scheme of initiating the polymerization of vinyl monomers [scheme (82a)] and cyclic ethers [scheme (82b)] using alkenes with electrophilic substituents (A is an electrophilic, D a nucleophilic substituent, and X a dissociable group)  

The tendency of vinyl ethers to polymerization decreases with the lowering of the alkyls inductive effect, i. e. ter/.-Bu iso-Pr Et -Bu, iso-Bu. Polymerization only takes place in strongly polar solvents such as acetonitrile or nitromethane. 

---