A Highly Soluble, Fully Aromatic Fluorinated 3D Nanostructured Ladder Polymer

A new, high-molecular-weight, aromatic fluorinated ladder polymer has been obtained by the superacid-catalyzed, nonstoichiometric, step polymerization of a xanthenediol with trifluoroacetone. The polymerizations carried out at room temperature in a mixture of trifluoromethanesulfonic acid (CF3SO3H, TFSA) with methylene chloride resulted in a polymer completely soluble in acetone, methylene chloride, chloroform, THF, methanol, DMF, NMP, and DMAC. The chemical composition of the ladder polymer has been confirmed by the complementary experimental and calculations studies of the 13C and 19F NMR spectra and the calculations of reaction pathways. It was also found that the growth of the fully fused-ring backbone polymer chain occurs in all three dimensions due to the formation of regioisomeric fragments. Appropriate films, for the determination of gas permeation coefficients, were obtained by casting. According to gas permeation experiments, the ladder polymer falls above Robeson's 2008 updated upper bound for the O2/N2 gas pair.