Unsaturated poly(ester–imide)s from hydroxy-terminated polybutadiene, dianhydride and diisocyanate

Hydroxy terminated polybutadiene has been used for the first time in the synthesis of poly(ester–imide)s [P(E–I)s]. Anhydride terminated polyester prepolymers were prepared by the reaction of two different polyols––polytetramethyleneoxide glycol (PTMG) of molecular weight 1000 and hydroxy terminated polybutadiene (HTPB) of molecular weight 2500––and different dianhydrides––pyromellitic dianhydride (PMDA), benzophenonetetracarboxylic dianhydride (BTDA) and 4,4′-(hexafluoroiso-propylidene)diphthalic anhydride (HFDA). The prepolymers were then reacted with different diisocyanates––80:20 mixture of 2,4- and 2,6-tolylene diisocyanate (TDI), 1,6-hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI) and 4,4′-methylene bis(phenylisocyanate) (MDI) resulting in P(E–I)s. The P(E–I)s were characterised by FT-IR, FT-NMR, GPC, TGA, DSC and for static and dynamic mechanical properties. The polymers based on PTMG showed two distinct melting points and behave as thermoplastic elastomers. The thermal stability and mechanical properties of P(E–I)s based on HTPB were substantially higher than those based on PTMG.