Hydrocarbon ladder aromatics from a Diels‐Alder reaction

The Diels‐Alder homopolycycloaddition of 2,5‐diphenyl‐3,4‐(5,6‐acenaphthylenylene)‐cyclopentadienone (VIII) affords a low molecular weight soluble ladder polymer having reduced specific viscosities between 0.17 and 0.25 dl/g in benzene and an insoluble fraction of higher molecular weight. The ladder polymers exhibited a major TGA break at 450°C in an air atmosphere and lost approximately 30% of their weight at 700°C in a nitrogen atmosphere.