Synthesis and properties of alkylene‐linked aromatic polyimides

Abstract

Abstract Alkylene‐linked aromatic polyimides were prepared from a family of new dianhydride monomers and aromatic diamines. The dianhydrides were synthesized by Friedel‐Crafts catalysis of the condensation of ditertiary alcohols with o ‐xylene, subsequent oxidation of the aryl methyl groups to carboxy, and finally, dehydration of the ortho ‐carboxy substituents to anhydride groups. Alkylene‐linked aromatic polyimides, with up to 8 methylene groups in the polymer chain, are stable to 400°C in air and can be extruded or compression‐molded at 300°C. In addition, these polymers are soluble in solvents within the solubility parameter range of 10.4 ± 1.2.