Imide and amine functions are good curing agents for epoxy resins. Thus, a 1:2 ratio of cyclobutanetetracarboxylic dianhydride [4415-87-6] and p-phenylenediamine [106-50-3] reacted in DMF to form the amic acid [91301-67-6] after 4 h at room temp.; a 3:2 mol ratio of pyridine and Ac2O was added to the amic acid soln. and the mixt. was heated to 80° to form the N,N'-diaminophenylcyclobutanetetracarboxylic diimide (I) [91301-63-2]. When 11.1 g triglycidyl-p-aminophenol was mixed with 2.97 g I and cured 3 h at 120° and 3 h at 204°, the softening point of the cured system was >300°.

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