| 摘要 |
<p>Polyimides with recurring units of formula: (R is a divalent aliphatic or aromatic gp.). Films, foils, fibres and coatings with strong intrinsic colour. Polymers have high heat-stability, resist attack by chemical reagents and radiation. Give stable solns. By polycondensation of 1,4-benzoquinone tetracarboxylic anhydride or 1,4-benzohydroquinone tetracarboxylic acid anhydride with diamino cpds. in soln. or bulk at room temp. to 350 degrees C. The polyimides may be converted to soluble form by reduction and worked into fibres, films or coatings by re-oxidation.</p> |
