Preparation and properties of aromatic polyethers containing acetylene groups in the backbone

Novel difluoroaromatic compounds containing acetylene groups were prepared. The reactivity of the monomers in nucleophilic substitution was evaluated from the positive charges on the carbon of C-F bonds calculated using the s emiempirical PM3 method. It was found that there is a good correlation betw een the charge calculated and the chemical shifts in the F-19 NMR spectra. Reactions of the monomers with various bisphenols under the nucleophilic su bstitution reaction conditions gave aromatic polyethers. The glass transiti on temperatures of the polyethers were in the range of 145 similar to 280 d egrees C, and the temperature at 10% weight loss were in the range of 410 s imilar to 545 degrees C in the air. DSC revealed that acetylene groups in t he polyether backbone reacted to crosslink at ca. 350 degrees C to give sol vent resistant polymers.