novel polys are prepared by the aromatic nucleophilic displacement reaction of novel di monomers with activated aromatic dihalides or activated aromatic dinitro compounds . the polymerizations are carried out in polar aprotic solvents such as n - methyl - 2 - pyrrolidinone or n , n - dimethylacetamide using alkali metal bases such as potassium carbonate at elevated temperatures under nitrogen . the di monomers are synthesized by reacting phenyl - 4 - hydroxybenzoate with bisarylenes in diphenylsulfone . moderate molecular weight pnabis of new chemical structures were prepared that exhibit a favorable combination of physical and mechanical properties . the use of the novel dis permits a more economical and easier way to prepare pnabis than previous routes .