Preparation of Highly Fluorinated Poly(ether sulfone)s under Mild Polycondensation Conditions Using Molecular Sieves

Abstract

Highly fluorinated poly(ether sulfone)s were prepared by a modified polycondensation technique, using a molecular sieve dehydrating apparatus in order to efficiently remove water under mild conditions. Consequently, side reactions were minimized, which resulted in the formation of polymers free of microgels. This reaction was also used to introduce pentafluorostyrene moieties into the polymer to provide crosslinking functionalities.

Multiblock sulfonated–fluorinated poly(arylene ether)s for a proton exchange membrane fuel cell

“…1). It is known that perfluoroaromatic monomers are highly reactive toward the nucleophilic aromatic substitution reaction and high molecular weight polymers form at relatively low temperature and short periods of time [11][12][13]. Several fluorinated oligomers were synthesized with molecular weights ranging from 2 to 60 K. Low molecular weight samples formed white powder-like products after isolation, whereas the high molecular weight sample formed white fibrous material.…”

Highly Fluorinated Poly(arylene ether ketone) Prepared by a CaH2‐Mediated Polycondensation Reaction

“…[4][5][6][7][8][9] Even under mild reaction conditions (i.e., at 113 8C) when molecular sieves were used to dehydrate the solution, a shoulder peak associated with branched structures was observed in the GPC curves of the final products. [3,13] In addition, it was also noted that molecular weights obtained were always lower than the designed values due to this side reaction upsetting the Summary: A new reaction procedure has been developed for the polycondensation of hexafluorobisphenol A (6F-BPA) with bis(pentafluorophenyl) ketone (BPK) in dimethylacetamide (DMAc). In this reaction, CaH 2 has been used as a base to facilitate the formation of the phenolate; an alkali metal fluoride was used as a catalyst.…”

“…[16] Therefore, a low boiling, non-polar co-solvent such as toluene has been introduced into the reaction medium to facilitate the removal of water by azeotropic distillation [5][6][7] or by refluxing. [3,13] Unfortunately, this approach reduces the polarity of the polymerization medium and results in a lower selectivity of the reaction. In addition, the azeotropic distillation is not able to completely remove all the water from the reaction solution.…”

Synthesis and characterization of fluorinated crosslinkable poly(phthalazinone ether)s bearing tetrafluorostyrene groups for optical waveguides

“…Note that the specimens used to obtain these data were recovered by dropping the reaction solution into a mixture of acidic water/methanol (2:1 v:v) so that both the polymer and low molecular weight cyclic oligomers were collected. 22 The presence of cyclic oligomers can be clearly seen as a small peak at 17 min in the low molecular weight region of the GPC curves.…”