Abstract: The present invention provides PMR-type polyimides that exhibit lower melt viscosities than PMR-type polyimides of the prior art. These PMR-type polyimides are created by incorporating flexible linkages, such as kinked structures and twisted or non-coplanar moietes into the backbone structure of the PMR. Specifically, the present invention provides for the production of PMR-type polyimides having 2,2′-disubstituted biaryls in the polymer backbone.

Abstract: Addition-cured polyimides that contain the reaction product of an aromatic triamine or trianhydride analogue thereof, a reactive end group such as 5-norbornene-2, 3-dicarboxylic acid, ester derivatives of 5-norbornene-2,3-dicarboxylic acid, anhydride derivatives of 5-norbornene-2,3-dicarboxylic acid, or 4-phenylethynylphthalic anhydride, an aromatic diamine, and a dialkyl ester of an aromatic tetracarboxylic acid. The resultant starlike polyimides exhibit lower melt flow viscosity than its linear counterparts, providing for improved processability of the polyimide. Also disclosed are methods for the synthesis of these polyimides as well as composite structures formed using these polyimides.