A highly fluorinated monomer, 1,3-bis(1,1,1,3,3,3-hexafluoro-2-pentafluorophenylmethoxy-2-propyl)benzene (12F-FBE), is obtained by reaction of the sodium salt of 1,3-bis(1,1,1,3,3,3-hexafluoro-2-hydroxy-2-propyl)benzene with pentafluorobenzyl bromide. 12F-FBE reacts with diphenols to give soluble, hydrophobic, low dielectric (2.30-2.43 at 10 GHz) polyethers. Thermal stability as measured by TGA (10 wt% loss) is moderate and ranges from 445 to 464 degreesC in air. Glass transition temperatures are between 89 and 110 degreesC. (C) 2003 Elsevier Ltd. All rights reserved.