Synthesis and Characterization of Poly(oxy-1,3-phenylenecarbonyl-1,4-phenylene) and Related Polymers

Abstract

The title composition, isoPEK, was prepared from 4-fluoro-3‘-hydroxybenzophenone in N-methylcaprolactam at 225 °C. Cyclomer formation interfered with polymerization at lower temperatures in alternative solvents and dominated in dilute solutions. The 50/50 to 70/30 copolymers of PEK and isoPEK were prepared using 4-fluoro-4‘-hydroxybenzophenone. An analogous composition, poly(oxy-1,3-phenylenecarbonyl-1,4-phenyleneoxy-1,4-phenylenecarbonyl-1,4-phenylene) or isoPEKEK, was prepared from 4,4‘-difluorobenzophenone and 3,4‘-dihydroxybenzophenone using similar conditions. Thermal crystallization of the copolymers was successful, but isoPEK and isoPEKEK were only capable of solvent-induced crystallization. The semicrystalline materials were studied by thermal analysis and X-ray diffraction. The copolymers melted at 264−307 °C and possessed random microstructures with isomorphic crystallization of the PEK and isoPEK repeat units. IsoPEK and isoPEKEK melted, respectively, at the low temperatures of 180 and 193 °C. IsoPEK crystallized with both Form 1 and Form 2 unit cells, while isoPEKEK and the copolymers crystallized with the Form 1 unit cell. IsoPEK was also prepared by ring-opening polymerization of its cyclomers in the melt using cesium fluoride as catalyst. The 3,4‘ catenation of the isoPEK repeat unit and the related monomers was used to rationalize the unique chemistry and properties of these polymers.

Poly(arylene ether)s with pendant diphenyl phosphoryl groups: Synthesis, characterization, and thermal properties

“…The synthesis of poly(arylene ether)s, (PAEs), is typically achieved through nucleophilic aromatic substitution, (NAS), reactions16, 17 of activated aryl dihalides (B 2 ) with bisphenolates derived from bisphenols (A 2 ). A wide variety of activating groups have been employed such as the strongly electron withdrawing sulfonyl,16–22 carbonyl,17, 23–26 and phosphoryl groups 2–4, 6, 7, 9–11, 27–29. However, a number of groups that do not possess very strong electron withdrawing capabilities, including azomethine,30 thianthrene,31 benzoxazole,32, 33 phenylquinoxaline,34–38 benzimidazole,39 triazole,40 and sulfide41 have been successfully utilized as the activating group in the synthesis of poly(arylene ether)s. In all of these cases, the activating group is located in the para position relative to the aryl halide and activates the electrophilic position by decreasing the electron density at the ipso carbon atom.…”

Synthesis of aromatic poly(ether amide amide ether ketone ketone)s by electrophilic Friedel–Crafts solution polycondensation

“…Poly(aryl ether ketone)s (PAEKs) are a class of important high‐ performance aromatic polymers, which are used in aerospace, electronics, and nuclear fields 1–5. Their excellent mechanical, thermo‐oxidative, electrical, and chemical resistance properties make them candidates for advanced materials 6–9. There are two general synthetic pathways to producing PAEKs 10–12.…”

Synthesis and characterization of poly(ether ketone ether ketone ketone)/poly(ether ether ketone ketone) copolymers containing naphthalene and pendant cyano groups

“…Poly(aryl ether ketone)s (PAEK) as high‐performance engineering plastics have attracted much attention 1–4. In fact, their excellent mechanical properties, good resistance to acidity and alkali, high thermal and thermo‐oxidative stability have made them very practical in our daily life and in industry.…”

“…Poly(aryl ether ketone)s (PAEK) as high-performance engineering plastics have attracted much attention. [1][2][3][4] In fact, their excellent mechanical properties, good resistance to acidity and alkali, high thermal and thermo-oxidative stability have made them very practical in our daily life and in industry. Among them poly(ether ether ketone) (PEEK), poly(ether ketone ketone) (PEKK) and poly(ether ketone ether ketone ketone) (PEKEKK) are the most widely used materials and have found many applications in aerospace, coating and insulating materials.…”