Synthesis of novel fluorine-containing poly(aryl ether ketone)s

Synthesis of Thermally Cross-Linkable Fluorine-containing Poly(aryl ether ketone)s I. Phenylethynyl Terminated Poly(aryl ether ketone)s

“…The obtained brown solid was recrystallized from 2-propanol. 5 Into a flask equipped with a condenser were placed 5.0 g of 4-acetoxy-phenylethynylbenzene (21 mmol), 47 mL of THF and 47 mL of methanol. 3.7 g of sodium hydroxide (93 mmol) dissolved in 31 mL of water was added to this solution.…”

“…Table IV Thermal stability estimated by TGA is also shown in Table II. Temperatures of 10% weight loss in nitrogen (Td10) of cured PEK-PEP are quite high, which is in the range from 544 to 598 • C. We have reported that Td10 of the F-PEKs which do not possess the phenylethynyl moiety ranges from 499 to 553 • C. 5 Compared with these Td10s, thermal stability of PEK-PEP is improved by about 40 • C due to the crosslinking. The TGA curve of the cured PEK-PEP is shown in Figure 7 with that of F-PEK.…”

“…We had prepared novel fluorine-containing PEKs derived from PFBA and reported so far. 5 These PEKs (F-PEKs) described in Scheme 1 exhibit outstanding solubility, thermal stability, low dielectric constant, low moisture absorption and high transparency. Hence, they are expected to be available for optical and electric materials.…”

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

“…Fluorinated poly(arylene ether ketone)s (FPAEK) [1][2][3][4][5] are conventionally prepared by the polycondensation of the phenol groups of hexafluorobisphenol A (6F-BPA) with para-fluorines of bis(pentafluorophenyl) ketone (BPK) using a nucleophilic aromatic substitution reaction (S N Ar), [6][7][8][9][10] which has been traditionally used for the preparation of nonfluorinated poly(arylene ether)s. [11,12] The major problem of this reaction when applied to the preparation of FPAEK is the high tendency of a side reaction at the ortho-fluorines of BPK, [3,4] which are activated by the strong electronwithdrawing effect of the ketone group. [10] This side reaction leads to the formation of branched and eventually crosslinked structures.…”

“…Initial work in our laboratory has shown that this side reaction produces a certain amount of branched and cross-linked structures in the final product when the conventional reaction conditions were used. [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).…”