Synthesis of fully aliphatic polyimides

Fully aliphatic polyimides (APIs) have been synthesized. APIs were prepared by poly(addition-condensation) of the alicyclic dianhydride bicyclo[2.2.2] octane-2,3,5,6-tetracarboxylic 2,3:5,6-dianhydride with the aliphatic diami ne 5-amind-1,3,3-trimethylcyclohexanemethylamine, the mixture of 2,5- and 2 ,6-bis(aminomethyl)bicyclo[2.2.1]heptane or 1,4-cyclohexanebis(methylamine) in m-cresol at high temperature. The polymerization proceeded smoothly at 200 degrees C and produced APIs with inherent viscosities up to 0.48 dl g(- 1) The APIs were soluble in a wide range of polar solvents and showed high thermal stability and excellent transparency.