Articulated para-ordered aromatic heterocyclic polymers containing diphenoxybenzene structures

A process for preparing a para-ordered aromatic heterocyclic polymer which comprises the following steps:

• (a) mixing an amino compound and a dicarboxylic acid with polyphosphoric acid, the amino compound being selected from the group of compounds having the following formulas:
• ##STR56## in which X is O, S or NH, and the dicarboxylic acid having the following formula:
• HO.sub.2 C--Ar--CO.sub.2 H,
• in which Ar is ##STR57## wherein R is a monovalent aromatic radical and R' and R" are individually selected from the group consisting of hydrogen, a monovalent aromatic radical, a monovalent aliphatic radical, a monovalent cycloaliphatic radical and a monovalent heterocyclic radical;
• (b) heating the mixture of step (a) in an inert gas atmosphere at a temperature ranging from about 100.degree. to 150.degree. C. for a period of about 12 to 24 hours;
• (c) at the end of the heating period of step (b), adding to the mixture a difunctional diphenoxybenzene having the following formula:
• Y--Ar'--Y,
• in which Y is CO.sub.2 H, CO.sub.2 CH.sub.3, COCl, CN or CONH.sub.2 and Ar' is ##STR58## (d) heating the mixture of step (c), in an inert gas atmosphere at a temperature ranging from about 150.degree. to 225.degree. C. for a period of about 36 to 96 hours;
• and
• (e) recovering a para-ordered aromatic heterocyclic polymer.