Synthesis of aliphatic polyimides containing adamantyl units

Aliphatic polyimides containing adamantyl units (APIs) were prepared by the poly(addition/condensation) of a dianhydride bicyclo[2.2.2]octane-2,3,5,6-tetracarboxylic 2,3 : 5,6-dianhydride with a rigid diamine, 1,3-diaminoadamantane or 3,3′-diamino-1,1′-biadamantyl, and a flexible diamine, 4,4′-methylenebis(cyclohexylamine) or 1,4-cyclohexanediamine. One-step polymerizations were conducted at 80–200°C in m-cresol, producing APIs with inherent viscosities up to 0.53 dL g⁻¹. These APIs are soluble in haloalkanes, m-cresol, and sulfuric acid and show high thermal stability and excellent transparency. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3584–3590, 1999