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

Abstract

ABSTRACT:Fluorine-containing poly(aryl ether ketone)s (PEKs) derived from 2,3,4,5,6-pentafluorobenzoic acid (PFBA) 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. In such applications, excellent solubility is of great advantage for making thin film and coating. Contrary to this advantage, this is of disadvantage from a point of solvent resistance. Thermally cross-linkable fluorine-containing PEKs terminated with phenylethynyl moiety (PEK-PEP) are synthesized to improve the solvent resistance in this study. Cross-linking reaction occurs over 320• Cand it brings about not only the outstanding solvent resistance but also the increase of T g . Relationship between the cross-linking density and T g can be fundamentally interpreted by configurational entropy theory. Furthermore, the cured PEK-PEPs possess excellent thermal stability with the 10% weight loss temperature in the range from 544 to 598• C.

Carbazole‐based poly(aryl ether ketone) containing crosslinkable allyl groups on the side chains: synthesis, characterization and properties

“…However, the rate of increase of T g decreased as the time was extended when the polymer was cured at any of the above curing temperatures, which was reflected through the respective comparison of tan 1 θ (tan 1 θ ′ = tan 1 θ ′′ > tan 1 θ ′′′), of tan 2 θ (tan 2 θ ′ > tan 2 θ ′′ > tan 2 θ ′′′) and of tan 3 θ (tan 3 θ ′ > tan 3 θ ′′ > tan 3 θ ′′′). This result agreed with the report by Yamashita and colleagues, where it was concluded that the mobility of molecular chains decreases upon increasing the conversion of the crosslinking reaction and therefore it results in a decrease in the reaction rate …”