abstract |
Polyimide resins useful at high temperatures are prepared from: (a) a dialkyl, trialkyl or tetraalkylester of biphenyltetracarboxylic acid; (b) phenylenediamine, preferably the phenylenediamine comprises a mixture of meta- and para-phenylenediamine; and (c) a divalent end cap compound that is capable of undergoing addition polymerization. |