Aromatic polyketones

It has already been shown (e.g. Chapters 20 and 21) that the insertion of a p-phenylene into the main chain of a linear polymer increased the chain stiffness and raised the heat distortion temperature. In many instances it also improved the resistance to thermal degradation. One of the first polymers to exploit this concept commercially was poly(ethylene terephthalate) but it was developed more with the polycarbonates, polysulphone, poly(phenylene sulphides) and aromatic polyketones. 

Aromatic polyketones are semicrystalline materials that contain both ketone groups generally flanked by aromatic units. Many also have within them ether moieties that allow for some flexibility and better processing. They have good thermal stabilities, as well as offering good mechanical properties, flame resistance, impact resistance, and resistance to the environment. 

In an earlier investigation by the author (1), polymeric ketones, (II), were prepared at ambient temperature by acid dehydration of a-phenyl acetic acid using phosphorus pentoxide and methane sulfonic acid as illustrated in Eq. (1). Aromatic polyketones formed from this process are provided in Table 2. 

TABLE 2. Selected Aromatic Polyketones Prepared by Dehydration of a-Phenyl Acetic Acid Using Phosphorus Pentoxide and Methane Sulfonic Acid"... 

Finally, it should be mentioned that self-poisoning due to erroneous integer folded depositions is only one manifestation of a productive reaction, which leads to thermodynamic stability, being retarded by a competing lower barrier reaction which almost leads to a stable product. The observations of a crystallization rate minimum in an aromatic polyketone [88], and recently an aromatic polyester [89], are further examples of such an occurrence. 

TABLE 1. Selected aromatic polyketones prepared according to the present invention. 

Musco [92] and Consiglio [93] have used palladium-oxazoline complexes (28,29) to produce styrenic copolymers that exhibit high optical rotations. Takaya has briefly noted the use of his novel phosphine-phosphite bi-dentate ligands for the enantioselective production of aromatic polyketones [82]. 

For example, the method for production of aromatic polyketones by means of Friedel-Craft polycondensation of bis(arylsilanes) with ehlorides of aromatie diearboxylic acids (isophthaloyl-, terephthaloyl-, 4,4 -oxy-dibenzoylchloride) at 20 °C in environment of dissolvent (1,2-diehloreth-... 

The aromatic polyketones can be synthesized [333] when conducting the Friedel-Craft polymerization with acylation by means of the interaction of 2,2 bis(arylphenoxy)bisphenyls with chlorides of arylenebicar-bonic acids in the presence of AICI3. The polyketones obtained using the most efficient 2,2 bis(4-bezoylphenoxy) bisphenyl are well soluble in organic solvents and possess high heat resistance. 

Also, the aromatic polyketones are produced [334] by the reaction of electrophylic substitution (in dispersion) of copolymer of aliphatic vinyl compound (1 -acosen) with N-vinylpirrolydone, at ratio of their links close to equimolar. 

The s mthesis of aromatic polyketone particles has been carried out [336] by means of precipitation polycondensation and is carried out at very the low concentration of monomer [0.05 mol/L]. The polyketones are... 

There exist reports on syntheses of fully aromatic polyketones without single ester bonds [339-349]. 

The fully aromatic polyketones without ether bonds were produced [339] on the basis of polyaminonitrile, which was synthesized from anions of bis(aminonitrile) and 4,4 -difluorobenzophenone using the sodium hydride in mild conditions. The acid hydrolysis of S5mthesized polyaminonitrile avails one to obtain corresponding polyketone with high thermal properties and tolerance for organic solvents. 

The aromatic polyketones without ester bonds can also be produced by the polymerization of bis(chlorbenzoyl)dimethoxybisphenyls in the presence of nickel compounds [341]. The polymers have the high molecular mass, the amorphous stmcture, the glass transition temperature 192 °C and 218 °C and form abiding flexible films. 

The known aromatic polyketones (the most of them) dissolve in strong acids, or in trifluoroacetic acid mixed with methylenechloride, or in trifluoro-acetic acid mixed with chloroform. 

The Refs. [352-355] report on syntheses of carding aromatic polyketones. 

There are contributions [356,357] devoted to the methods of synthesis of aromatic polyketones on the basis of diarylidenecycloalkanes. 

The Refs. [359, 360] report on different s5mtheses of isomeric aromatic polyketones. Three isomeric aromatic polyketones, containing units of 2-trifluoromethyl- and 2,2 -dimetoxybisphenylene were S5mthesized in Ref [326] by means of direct electrophylic aromatic acylated polycondensation of monomers. Two isomers of polyketone of structure head-to tail and head-to head contain the links of 2-trifrluoromethyl-4,4 -bisphenylene and 2,2 -dimethoxy-5,5 -bisphenylene. 

The aromatic polyketones, containing 1,4-naphthalene links were produced in Ref. [363] by the reaction of nucleophylic substitution of l-chlor-4-(4 -chlorbenzoyl)naphthalene with 1) 1,4-hydroquinone, 2) 4,4 -isopropylidenediphenol, 3) phenolphthalein, 4) 4-(4 -hydroxyphenyl) (2H)-phthalasine-l-one, respectively. All polymers are amorphous and dissipate in some organic solvents. The polymers have good thermo-stability and the high glassing temperatures. 

Russian and foreign scientists work on synthesis of copolymers [382-393] and block copolymers [394-399] of aromatic polyketones. 

The works on production of oligoketones and S5mthesis of aromatic polyketones on their basis are held in Kh.M. Berbekov Kabardino-Balkarian State University. 

Takeuchi Hasashi, Kakimoto Masa-Aki., Imai Yoshio. (2002). Novel Method for Synthesizing Aromatic Polyketones from Bis(arylsilanes) and Chlorides of Aromatic Bicarbonic Acids J. Polym. Sci. A, 40(16), 2729-2735. 

Maeyata Katsuya, Tagata Yoshimasa, Nishimori Hiroki, Yamazaki Megumi, Maruyama Satoshi, Yonezawa Noriyuki. (2004). Producing of aromatic polyketones on the Basis of 2,2 -Diaryloxybisphenyls and Derivatives of Arylenecarbonic Acids Accompanied with Polymerization with Friedel-Krafts Acylation React. And Fund. Polym, 61(1), 71-79. 

GibeonHarry, W., PandyaAshish. (1994). Method for Producing Aromatic Polyketones. US Patent 5344914. International Patent Catalogus C 08 G 69/10,... 

Yonezawa Noriyuki, Ikezaki Tomohide, Nakamura Niroyuki, Maeyama Katsuya. (2000). Successful Synthesis of aU-Aromatic Polyketons by means of Polymerization withAromatic Combination in the Presence of ]>lkkel Macromolecules, 33(22), 8125-8129. 

YonezawaNoriyuki, Nakamura Hiroyuki, Maeyama Katsuya. (2002). Synthesis of all-Aromatic Polyketones having Controllable Isomeric Composition and Containing Links of 2-Trifluorometylbisphenylene and 2,2 -Dimetoxybisphenylene. React. AndFunct Polym, 52(1), 19-30. 

Maeyama Katsuya, Sekimura Satoshi, Takano Masaomi, Yonezawa Noriyuki. (2004). Synthesis of Copolymers of Aromatic Polyketones React. And Funct Polym, 58(2), 111-115. 

For example, the method for production of aromatic polyketones by means of Friedel-Craft polycondensation of bis (arylsilanes) with chlorides of aromatic dicarboxylic acids (isophthaloyl-,terephthaloyl-,4,4 -oxydibenzoylchloride) at 20 °C in environment of dissolvent (1,2-dichlor-ethane) in the presence of aluminum chloride is proposed in Ref [331], The polyketones have the intrinsic viscosity more than 0.37 deciliter/gram (at 30 °C, in concentrated H SO ), glass transition temperature is 120-231 °C and melting point lies within 246-367 °C. The polyketones start decomposing at a temperature of 400 °C, the temperature of 10% loss of mass is 480-530 °C. 

The s mthesis of aromatic polyketone particles has been carried out [336] by means of precipitation polycondensation and is carried out at very the low concentration of monomer [0, 05 mol/liter]. The polyketones are produced from bisphenoxybenzophenone (0,005 mole) or isophlha-loylchloride (0.005 mole) in 100 milliliters of 1,2-dichloroethane. Some of obtained particles have highly organized the needle-shaped structure (the whisker crystals). The use of isophthaloyl instead of terephthaloyl at the same low concentration of monomer results in formation of additionally globular particles, the binders of strip structures gives rise. The average size of needle-shaped particles is 1-5 mm in width and 150-250 mm in length. 

For increasing of basic physical-mechanical characteristics and reprocessing, in particular of solubility, the S5mthesis of aromatic polyketones is lead through the stages of formation of oligomers with end functional... 

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