Poly synthetic routes

Alternative synthetic routes to poly(arylene sulfide)s have been pubHshed (79—82). The general theme explored is the oxidative polymerization of diphenyl disulfide and its substituted analogues by using molecular oxygen as the oxidant, often catalyzed by a variety of reagents ... 

Hydroformylation. Hydroformylation of aEyl alcohol is a synthetic route for producing 1,4-butanediol [110-63-4] a raw material for poly(butylene terephthalate), an engineering plastic (qv) many studies on the process have been carried out. 

In conclusion, some trends can be gleaned from an examination of the content of the symposium as a whole. The growth in research efforts addressing the synthesis and properties of poly(diorganosilanes) will likely continue. The unique photophysical properties of this newly developed class of inorganic macromolecules (12) together with ready synthetic routes will be contributing forces here, and no doubt new vectors will arise. 

A typical synthetic route to the incorporation of pendent carboranyl units into a polymer chain is shown in scheme 3. Poly(o-carboranyl-organo-siloxane)s have been successfully prepared through hydrolysis of dimethyldichlorosilane in the presence of carboranedichloromethylsilane. The polymer has some of the elastomeric characteristics of the parent poly(siloxane) however, the thermal-oxidative cleavage of the o-carboranyl pendent group is reported to occurat lower temperatures than that for the thermooxidative cleavage of Si—O and Si—C bonds.10 Thermal studies have... 

This effect has also been observed in polyphosphazenes containing alkyl- or phenyl-carborane as pendent groups.12 A typical synthetic route to poly(phenyl-carboranyl-di-trifluoroethoxy-phosphazene) having pendent phenyl-carborane groups is shown in scheme 4. A substantial improvement in the thermal stability of the polymer was observed. This is attributed to a retardation of the ring-chain de-polymerization mechanism due to steric hindrance effects of the carborane units, inhibiting helical coil formation. 

Two-step synthetic routes to poly(/i-aminoborazines) from /i-chloroborazines involve initial nucleophilic reaction of the /i-chloroborazine with appropriate linking reagents followed by a deamination reaction of the as-obtained /i-aminoborazine. The 5-tiichloroborazine undergoes nucleophilic attack by ammonia or amine derivatives on the boron atom linked to chlorine atoms. For the same reasons previously quoted a tertiary amine (e.g., Et3N) must be added to precipitate the corresponding hydrochloride. 

Polybasic carboxylic hydroxy and amino acid aided synthetic routes directed towards obtaining mixed inorganic materials, especially for battery and fuel cell applications, are overviewed. It has been shown that, in spite of enormous number of papers on the subject, significant efforts should be undertaken in order to understand the basic principles of these routes. Possible influence of the structure of reactants employed in the process (acids, poly hydroxy alcohols, metal salts) is put forward, and some directions of future work in the field are outlined. 

H. Meng, W. Yu, and W. Huang, Facile synthetic route to a novel electroluminescent polymer — poly(p-phenylene vinylene) containing a fully conjugated aromatic oxadiazole side chain, Macromolecules, 32 8841-8847, 1999. 

A. Bolognesi, W. Porzio, G. Bajo, G. Zannoni, and L. Fanning, Highly regioregular poly (3-alkylthiophenes) a new synthetic route and characterization of the resulting polymers, Acta Polym., 50 151-155, 1999. 

Abstract This review describes recent results in the field of poly(aryleneethynylene)s (PAEs) that contain metal ions in the polymer backbone, or in the polymer side chain. This work is focused primarily on polymers possessing ligands of metal complexes as part of the aryle-neethynylene chain. PAEs with porphyrinylene in the backbone have also been addressed. Synthetic routes toward the polymers, as well as their photochemical, photophysical, and electrochemical properties, are presented. Monodisperse oligo(phenyleneethynylene)s with terminal metal complexes or with a ferrocene and thiol at each end are mentioned. 

The Pd-catalyzed C-C coupling (Sonogashira coupling) was applied to polymer synthesis about 20 years ago [23-25], and has especially been developed for the synthesis of n-conjugated poly(aryleneethynylene)s (PAEs) (for reviews, see refs. [16,26-33]). Recently other synthetic routes for PAEs were also developed, e.g., the alkyne metathesis method [28, 34] and the coupling reaction of =C-MR3 with R X (M=Si [35, 36] or Sn [37, 38]). In this review, we are concerned with the synthesis and chemical properties of PAEs with heteroaromatic rings. 

The incorporation of SO2 groups into the main chain of poly(phenylene ether)s leads to poly(phenylene ether sulfone)s. The preferential synthetic routes are ... 

The second synthetic route to PAE containing quinoxaline units involved the reaction of an aromatic dihydroxy quinoxaline or aromatic bis(hydroxy-quinoxaline) with activated aromatic difluoro compounds (Eq. (3)) [15]. The dihydroxy quinoxaline and bis(hydroxyquinoxaline) monomers were readily prepared from the condensation of 1,2-diaminobenzene with 4,4 -dihydroxyben-zil and aromatic bis(o-diamines) with 4-hydroxybenzil, respectively. The Tgs of a series of PAE containing quinoxaline units are presented in Tables 3 and 4. For these polymers, the trend for the Tg is sulfone > carbonyl > terephthaloyl-> isophthaloyl. This trend holds for most polymer families when polymers of similar molecular weights are compared. Several polyphenylquinoxalines of the same chemical structure as those in Table 3 were also prepared by the poly-... 

Poly(arylene ether phthalazine)s were prepared by two different routes [47], As shown in Eq. (13), one route involved the preparation of precursor poly(arylene ether diketone)s and subsequent reaction with hydrazine while the other route concerned the reaction of difluorophthalazine monomers with various bisphen-ols. The poly(arylene ether phthalazine)s prepared by the two routes exhibited very similar Tgs. The synthetic route to the difluorophthalazine monomers is also shown in Eq. (13). A comparison of the properties of a representative series of poly (ary lene ether diketone)s and the corresponding poly(arylene ether... 

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