Anionic and cationic polymerization of norbornadiene in hydrocarbon

Norbornadiene (NBD) has been successfully polymerized in benzene solvent in high yield (up to 100%) using AlCl₃ as initiator. Anionic polymerization of the same compound was achieved using butyllithium as initiator. According to the IR and NMR data, both polymers have a 2,6-disubstituted nortricyclene structure. The cationic polymerization gave an amorphous polymer; the anionic polymerization resulted in the formation of a crystalline product showing higher stability.