| abstract |
A class of polymers comprises one or more 2-amidomethylbenzazole units,n contained within the main polymer backbone, wherein Ar is Ar¹ or Ar², wherein Ar¹ is a tetravalent aromatic nucleus having two pairs of valences, the members of each pair being situated on adjacent carbon atoms; Ar² is a trivalent aromatic nucleus in which at least two of the valences are situated on adjacent carbon atoms; and X is -NR⁴_, -O-, or -S-, where R⁴ is hydrogen or alkyl of 1 to 8 carbon atoms or an aryl group. |