| abstract |
Polyquinazolones suitable for moulding and forming films, fibres and lacquers have relative viscosity 1.1-1.8, softening point above 300 degrees C and structure (I): where R is alkyl, aryl; R1 is a simple link, O, S, sulphonyl, carbonyl, alkylene, cycloalkylene, aralkylene or where X is O, S, sulphoxide, sulphonyl or carbonyl R2, R3 are divalent aromatic (condensed ring) residues or R3 is -R6-Hy-R2 (R6 is R2 or is different) and Hy is R4, R5 are H or C1-5 alkyl, n is greater than 8. |