Low-Cost Solvents for the Preparation of Polyphenylquinoxalines

Recent studies have shown there to be great potential for reducing the cost of polyphenylquinoxalines by significantly lowering the cost of the requisite monomers. Such reductions have made previously insignificant solvent costs an important factor in the overall resin cost. Accordingly, a polyphenylquinoxaline was prepared in solvents where relatively expensive isomerically pure m-cresol was replaced with technical phenol or cresol. A series of comparisons was made between these polymers and a polyphenylquinoxaline prepared in the conventional solvent. It was conclusively shown that each of the polymers was of comparable quality in terms of thermal oxidative stability and molecular weight. Thus, less costly solvents can be used for the preparation of polyphenylquinoxalines, thereby further reducing the cost of these superior resins.