Molecular architecture effect on reactivity of polynorbornenes with pendant α,β-unsaturated amide or ester bridged chains via ring-opening metathesis polymerization

The molecular architecture effect on active structure of miscellaneous polynorbornenes (Scheme 1) was investigated with pendant α,β-unsaturated amide or ester groups via ring-opening metathesis polymerization (ROMP). Remarkable differences in the reactivity and polymerization behavior of active norbornenes depend on various molecular architectures. Polynorbornenes derived from active norbornenes with ethylene between urethane group and ester group such as 3a,b (Scheme 1) showed excellent solubility. Organo-insoluble precipitate was obtained after ROMP of 5c with the amide group. Random copolymerization technique of bicyclo[2.2.1]hept-2-ene (NB) and 5c with amide group was considered to be a strategy to overcome the formation of precipitates, which expected to decrease the hydrogen bonding between two amide groups. High performance polynorbornenes with active groups could be designed with high potential of application for photoresist, UV curing and elastomers. Functional poly(5b) was incorporated into poly(methyl methacylate) [poly(MMA)] to produce AB cross-linked materials. The AB cross-linked material [15 wt% poly(5b), Td10=355 °C in nitrogen] had higher thermal stability than pure poly(MMA) (Td10=250 °C in nitrogen).