NEW POLYMER SYNTHESES, 94 - THERMOSETTING, CHOLESTERIC OLIGOESTERS CONTAINING MALEIMIDE OR NADIMIDE END-GROUPS

Twenty four cholesteric and telechelic oligoesters were prepared havin g two maleimide or nadimide end groups. All oligoesters were synthesiz ed by copolycondensation of isosorbide and methyl-or tert-butylhydroqu inone with suitable dicarboxylic acid chlorides in 1-chloronaphthalene at 200 degrees C. 4-Maleimidophenol or 4-nadimidophenol was added as terminating reagent. The isolated oligoesters had inherent viscosities in the range of 0,14-0,20 dl/g (CH2Cl2/trifluoroacetic acid) and the presence of the imide end groups was confirmed by H-1 and C-13 NMR spe ctroscopy. Most oligoesters were non-crystalline materials with glass transition temperatures in the range of 105-130 degrees C. Most oligoe sters were capable of forming a Grandjean texture upon shearing of the cholesteric melt, and thermal crosslinking in the LC phase was possib le upon heating to 250 degrees C. In several cases the thermal curve a llowed a fixation of the Grandjean texture.