Novel lactamimide-containing polymers were first synthesized by the bisimide-lactamimide ring contraction of 1,8:4,5-tetracarboxylic bisimide-containing polymers. The conversion of bisimide moieties was in the range 60–100% depending on polymer chain flexibility. The yields of lactamimide units were between 75 and 100% with respect to bisimide group conversion owing to the insolubility of polymers during lactam ring closure. No appreciable hydrolytic degradation of polymers was observed as followed from GPC data. Both u.v. longwave absorption and emission maxims in polylactamimides were 20–50 nm red shifted compared with those of polyimides due to intramolecular charge transfer. It was found that the thermostability of lactamimide units was close to that of bisimide as proved by TGA.
Посилання на статтю:
Bisimide-lactamimide ring contraction in six-membered polyimides / Serguei Fomine, Lioudmila Fomina, Rogelio Arreola, Juan Carlos Alonso // Polymer. – 1999. – N 40. – P. 2051–2058.