Synthesis of aliphatic polyimides containing adamantyl units

Aliphatic polyimides containing adamantyl units (APIs) were prepared by the poly(addition/condensation) of a dianhydride bicycle[2.2.2] octane-2,3,5,6 -tetracarboxylic 2,3:5,6-dianhydride with a rigid diamine, 1,3-diaminoadama ntane or 3,3'-diamino-1,1'-biadamantyl, and a flexible diamine, 4,4'-methyl enebis(cyclohexylamine) or 1,4-cyclohexanediamine. One-step polymerizations were conducted at 80-200 degrees C in m-cresol, producing APIs with inhere nt 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 t ransparency. (C) 1999 John Wiley & Sons, Inc.