Polybenzazole polymers can be synthesized rapidly in large quantities at high molecular weight and high concentration by a two-step process of forming oligomers in a batch reactor and advancing the molecular weight of the polymer in an extruder.
A shaped article of an aromatic heterocyclic copolymer can be produced by (a) reacting (i) an aromatic diaminodithiol compound, hydrogen atoms of thiol groups of the aromatic diaminodithiol compound being substituted with substituted or unsubstituted alkyl groups, and (ii) an aromatic diamino compound separately with (iii) a dicarboxylic acid derivative in an organic solvent to produce two types of oligomers; (b) reacting the two oligomers in an organic solvent to produce a precopolymer; (c) heating the precopolymer to cause a thiazole ring closure reaction, thereby producing the aromatic heterocyclic copolymer; (d) finely comminuting the aromatic heterocyclic copolymer to obtain fine powder; and (e) molding the powder at an elevated temperature to form an article of a desired shape.
In a process for the preparation of poly-o-hydroxyamides and poly-o-mercaptoamides, a bis-o-aminophenol or a bis-o-aminothiophenol is reacted with a dicarboxylic acid derivative with the following structure: ##STR1## where D=O, S, or NH, and where R* is the parent body of the dicarboxylic acid and at least one of the groups R.sup.1 through R.sup.5 is F or CF.sub.3.
In a process for the preparation of poly-o-hydroxyamides and poly-o-mercaptoamides, a bis-o-aminophenol or a bis-o-aminothiophenol is reacted with a dicarboxylic acid derivative of the following structure: ##STR1## with D=O, S, or NH and where R* is the parent body of the dicarboxylic acid and at least one of the groups R.sup.1 and R.sup.2 is CN or NO.sub.2.
In a process for the preparation of poly-o-hydroxyamides and poly-o-mercaptoamides, a bis-o-aminophenol or a bis-o-aminothiophenol is reacted with a dicarboxylic acid derivative of the following structure: ##STR1## with D=O, S, or NH and where R* is the parent body of the dicarboxylic acid and the groups R.sup.1 through R.sup.4 are H, F, CH.sub.3, or CF.sub.3 (with a maximum of two CH.sub.3 or CF.sub.3 groups).
In a process for the preparation of poly-o-hydroxyamides and poly-o-mercaptoamides, a bis-o-hydroxyamide or a bis-o-mercaptoamide is reacted with a dihydroxy compound in the presence of a basic catalyst.
