Novel Preparative Method of Aromatic Polyesters and Polyamides using Aromatic Bisketene Compounds

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9,10-Dicarbonyl-9,10-dihydroanthracene (1) and 1,4-dicarbonyl-1,4-dihydronaphthalene (2) were too reactive to isolate as pure crystals at room temperature, but they were capable of keeping unchanged in degassed benzene. 1 reacted with four kinds of benzoquinones at room temperature to give corresponding polymers in moderate yields, which were found to be aromatic polyesters on the basis of their characterizations. It was found that 1 is able to react spontaneously with quinones to form ester linkage via direct addition reaction. The benzene solution of 2 with its high concentration is not available because of higher reactivity compared to 1. Acid chloride, precursor compound of 2, was used instead in this reaction. The addition of base to the mixture solution of acid chloride and quinones or quinone diimines gave corresponding polymers in moderate yields, which were found to be aromatic polyesters and polyamides, respectively, on the basis of their characterizations. 2 is able to react spontaneously with quinones and quinone diimines to form ester and amide likage, respectively, via direct addition reaction. 3, produced in the system by the irradiation of benzocyclobutenedione, reacted with quinones or quinone diimines to give corresponding polymers in moderate yields, which were found to be aromatic polyesters and polyamides, respectively, on the basis of their characterizations. By the ESR measurement in the reaction of the 3-benzoquinone system, it was found that the polymerization proceeds radical mechanism. And also, the molecular weights of polymers obtained increased with the time. These facts suggested that polymerization proceeds via diradical coupling mechanism. However, long time irradiation induced the decomposition of polymer, leading to decrease of the molecular weights.