Imide-aryl ether thiophene copolymers were prepared and their thermal
and mechanical properties were investigated. A key feature of these co
polymers is the incorporation of the 2,5-thiophene moiety using 5,5'-b
is[(3-aminophenoxy)thienyl-2] ketone or 5,5'-bis[(4-aminophenoxy)thien
yl-2] ketone as diamines in polyimide syntheses. The preparation of th
ese thiophene diamines involved the nucleophilic aromatic substitution
of bis(5-chlorothienyl-2) ketone with either 3- or 4-aminophenol in N
-methyl-2-pyrrolidinone using potassium carbonate. These diamines were
reacted with various compositions of pyromellitic dianhydride and 4,4
'-oxydianiline to synthesize the desired poly(amic acid)s. Films were
cast and cured (300-degrees-C) to effect the imide formation, and the
resulting films showed tough ductile mechanical properties with high g
lass transition temperatures that decreased with increasing thiophene
diamine content.