Poly ketone

Scheme 6.18 Synthesis of poly(ketone ketone sulfone) via a polyaminonitrile precursor.

Generally, trialkylboranes are useful intermediates in the field of organic synthesis with versatile reactivity. The polymers prepared by polyaddition between diene monomers and thexylborane are polymer homologues of trialkylboranes, which can be converted to poly(alcohol)s, poly(ketone)s, and other polymers having some functional groups (scheme 4).8-12... 

The polymers prepared from thexylborane and diene monomers were reacted with carbon monoxide at 120°C, followed by treatment with NaOH and H202 to produce a polyalcohol (scheme 5).13 This conversion includes migration of the polymer chain and thexyl group from the boron atom to carbon, as shown in scheme 5. When this reaction was carried out under milder condition, poly(ketone) segments were included in the polymer backbone due to an incomplete migration of the thexyl group. 

To synthesize the poly(ketone)s selectively, the reaction between the organoboron polymers and KCN was reported (scheme 6).8 After oxidation of the reaction mixture, followed by coagulation, the desired poly(ketone)s were obtained. The yielded polymers... 

Hexafluoroisopropylidene-unit-containing aromatic poly(ether ketone)s were first synthesized from an alkaline metal salt of Bisphenol AF (1) and 4,4 -difluoro-benzophenone.14 Cassidy and co-workers prepared hexafluoroisopropylidene-unit-containing poly(ether ketone)s by condensing 2,2-bis[4-(4-fluorobenzoyl)-phenyl]-l,l,l,3,3,3-hexafluoropropane (9) and 2,2-bis[4-(4-fluorobenzoyl)-phenyljpropane (10) with Bisphenol AF (1) or Bisphenol A (4) (Scheme 7).15 The reactions are nucleophilic aromatic displacements and were conducted in DMAc at 155- 160°C with an excess of anhydrous potassium carbonate. After 3 to 6 h of reaction, high-molecular-weight poly(ketone)s are obtained in high yields. 

A powerful and efficient method for the preparation of poly(ketone)s is the direct polycondensation of dicarboxylic acids with aromatic compounds or of aromatic carboxylic acids using phosphorus pentoxide/methanesulfonic acid (PPMA)16 or polyphosphoric acid (PPA)17 as the condensing agent and solvent. By applying both of these reagents to the synthesis of hexafluoroisopropylidene-unit-containing aromatic poly(ketone)s, various types of poly(ketone)s such as poly(ether ketone) (11), poly(ketone) (12), poly(sulfide ketone) (13), and poly-... 

Poly(ketone) (12) and poly(sulfone ketone) (14) are produced according to Scheme (9). They contain significant numbers of phenylene units substituted in p- and o-positions in addition to the m-phenylene units. 

The molecular weights of poly(ketone)s obtained from diphenyl ketone and diphenyl sulfone are lower than those from diphenyl ether and diphenyl sulfide. The former monomers possess highly electron-withdrawing carbonyl or sulfone groups, which lower the electron density of the rings. 

Poly(ketone)s obtained from 2,2-bis(4-carboxyphenyl)-l 1,1,3,3,3-hexa-fluoro-propane 15 with diphenyl compounds dissolve readily in aprotic polar... 

Table 9.8. Thermal Properties of Poly(Ketone)s Having Hexafluoroisopropylidene Units18... 

Crystallinity of these hexafluoroisopropylidene-unit-containing poly(ketone)s is low except for poly(sulfide ketone) (13). The water contact angle for the fluorine-containing poly(ketone) films is high, being 98° for poly(ether ketone) (11), from 2,2-bis(4-carboxyphenyl)-l,l, l,3,3,3-hexafluoropropane(15) and 96° for poly(sulfide ketone) (13) from 15, whereas it is 78° for poly(ether ketone) from 2,2-bis(4-carboxy-phenyl)propane (16) and 74° for the poly(sulfide ketone) from 16. This result indicates that the substitution of isopropylidene units of poly-(ketone)s with hexafluoroisopropylidene units has a remarkable effect on the surface properties of poly(ketone) films. 

ESR spectra, 511 Uranium(VI) complexes dioxoneocupferron, 512 Uranium hexaalkoxides physical properties, 347 Uranyl complexes cupferron, 512 formamide, 491 glycolic acid, 472 hexafluoroacetylacetone, 373, 377 photochemistry, 385 rearrangement, 384 maleic acid conformation, 467 neutral 1,3-diketones, 402 poly ketones, 399 Urea... 

Different mechanistic interpretations of the formation of an alternating propylene/carbon monoxide copolymer of poly(spiroketal) structure were considered [107, 478, 480, 481, 489]. Any reasonable proposal, however, needs to take into account the nature of the end groups in the copolymer chains. To date this has not been possible owing to the low solubility of the copolymer in solvents other than hexafluoroisopropanol however, this solvent, probably because of its acidic nature, causes transformation of the poly(spiroketal) structure into an isomeric poly(ketone) structure [489]. The formation of a cyclic polymeric structure could be favoured by minor entropy loss due to the intramolecularity of the process [480,481] and by the peculiar conformational situation of the poly(ketone) structure [491]. 

Under most conditions, only the simple polypropylene ketone) is formed in propylene/carbon monoxide alternating copolymerisation. Isomerisation of poly(ketone) to poly(spiroketal) can occur, and it may be assisted by cationic palladium species and protonic acids. It must be emphasised that a low reaction temperature favours the formation of a spiroketal structure [107]. At a temperature above the ceiling temperature, the poly(spiroketal) depolymerises to the more flexible and entropically favoured poly (ketone) [481]. 

In earlier investigations, the author developed catalytic methods for preparing ketones and poly ketones using acetylacetonato-vanadium(III) (1). Oxidative process for ethers using acetylacetonatocobalt(II) are also described by the author (2). 

In contrast to polyolefins such as polypropene, polyketones possess true stereo-genic centers along the polymer backbone. Therefore, poly ketones present a unique opportunity to use simple monomers in combination with chiral, enantio-merically pure palladium catalysts to prepare highly isotactic, optically active polymers (or oligomeric compounds) with main-chain chirality. 

Various copolymers and terpolymers poly(ketone)s containing functional groups (phenolic or phenyl ether substrates) were prepared using ]Pd(dppp)(CH3CN)2] (BF4)2 as the catalyst precursor [124, 125]. Using the same catalytic system meso-genic 1-alkenes were also copolymerized [126]. 

Indeed, it has been found 70 that under the conditions of the experiments, the proportion of quinone to maleic acid remains fixed and is not materially altered by introduction of quinone with benzene. However, the proportion of quinone is never large in tire case where solid catalysts are used. The mechanism of the further oxidation of quinone to maleic anhydride is somewhat speculative since the isolation of any of the intermediate compounds in this step has not been reported in the vapor phase oxidation experiments. However, the formation of a poly-ketone by the following reactions seems a possibility since it may be assumed that a continuation of the hydroxylation process followed by the molecular rearrangement, would be expected. 

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