| abstract |
Thermotropic polyesters of units of diacids, hydroxy acids, diols, and optionally polyestercarbonate-, polyesteramide-, polyssterimide- and/or polyester anhydride-structures, characterized in that a part of the diol component(s) is replaced by one or more dervative(s) of the following formula (I)n wherein nR, R₁ and R₂ which are the same or different, are hydrogen, alkyl radicals having 1 to 4 carbon atoms, cycloalkyl radicals having 3 to 6 carbon atoms, or aryl radicals, optionally substituted by one or more alkyl radicals having 1 to 4 carbon atoms, or substituted by halogen atoms like chlorine, bromine and/or fluorine, nR₃ is hydrogen or an akyl radical having 1 to 4 carbon atoms, nn is 0 or 1 and if n=1, then nX is -O-, -S-, or -N=, whereas m=1 or 2; nAr is phenyl, biphenyl or naphthyl. nThese polyesters can be produced from relatively cheap starting materials and possess excellent physical properties. |