New dimer for synthesis of high performance polymer matrix composites

摘要

An improved synthesis for PMR-type polyimides, including first preparing a dimer of 5-norbornene-2,3-dicarboxylic acid, or acid ester or anhydride and 4,4'methylenedianiline. This dimer is then reacted with the reaction product of the dimethyl ester (or dianhydride) of 3,3', 4,4'- benzophenonetetracarboxylic acid and 4,4'-methylenedianiline. The resulting polyimide prepolymer exhibits superior physical properties and is substantially free of the undesired trimer of 5-norbornene-2,3- dicarboxylic acid, or acid ester or anhydride and 4,4'-methylenedianiline. When this dimer is reacted with 3,3', 4,4'-benzophenonetetracarboxylic acid dianhydride methylenedianiline amic acid mixture, the resulting polyimide prepolymer exhibits superior physical properties.