DIRECT SYNTHESIS AND PROPERTIES OF POLYBENZODIPYRROLEDIONES FROM DIRECT SYNTHESIS AND PROPERTIES OF POLYBENZODIPYRROLEDIONES FROM DIBENZYLIDENEBENZODIFURANDIONES AND VARIOUS DIAMINES

In the reported investigation, aromatic and aliphatic polybenzodipyrrolediones have been synthesized directly by the solution cyclopolycondensation of two dibenzylidenebenzodifurandiones with four different diamines in refluxing m-cresol or o-phenylphenol in the presence of boric acid. The polymerizations proceeded smoothly in a homogeneous solution and afforded the heterocyclic polymers having inherent viscosities as high as 1. 0 almost quantitatively. All the polymers were readily soluble in a wide range of solvents, including N-methyl-2-pyrrolidone (NMP), hot m-cresol, and hot pyridine. Tough, transparent, yellow films could be fast from NMP solutions of the polymers. Thermogravimetric analysis of the aromatic polybenzodipyrrolediones showed a 10% weight loss temperature of 460-500 degree C under nitrogen. The results also indicated that the aromatic polymers were somewhat less thermally stable than wholly aromatic polypyromellitimides.