Polyethers and Polythioethers

These materials form yet another class of polymer which may be prepared by more than one polymerization method. For example polyoxymethylene (polyformaldehyde, polymethanal, acetal resin) may be prepared by double-bond polymerization from formaldehyde or by ring-opening of trioxane  

Other polyethers may be prepared either by condensation polymerization or by ring-opening, e.g. 

In practice those materials of significance as elastomers are produced by ring-opening. 

The introduction of C—O—C linkages into a polymer backbone otherwise consisting of carbon-carbon linkages increases the chain flexibility since the barriers to single-bond rotation in a C—O—C segment are lower than in a comparable C—C—C segment. This 

The most promising industrial polyether-polythioether rubbers may be classified into four types  

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There have been few recent studies on the synthesis of polyethers and polythioethers derived from vegetable oils, and all arise from castor oil-based monomers. They are, therefore, discussed in the next section devoted to this very special renewable resource. The same applies to polyanhydrides. 

In addition to the four classes of polyether and polythioether described above there has been an interest in the polyaddition products known as polyacetals but which may, somewhat loosely, be considered as a class of polyether ... 

The Use of Phthalimide Photochemistry in Macrocyclec Polyamide, Polyether, and Polythioether Synthesis... 

The phthalimides, that serve as starting materials for these photomacrocylization reactions are readily prepared by N-alkylation of potassium phthalimide with polyamide, polyether, and polythioether-linked mesylates or hahdes. As seen by viewing the processes included in Schemes 11 through 16, irradiation of the phthaHmido-silylpolyamides, -ethers and -thioethers in MeOH solution does indeed result in modestly to highly efficient production of the corresponding macrocyclic products. 

The variation in the complexation properties by this substitution (polyether to polythioether) was used by Cram for ion complexation and by Inouye for the synthesis of macrocycles for sugar recognition (Scheme 35) [71,88]. 

In 1973, the synthesis of titanium, zirconium, and hafiiium polyesters via reaction of the dicyclopentadienylmetal dichloride complexes with disodium dicarboxylates in either aqueous or organic solvents was reported (31). Aroimdthe same time the synthesis of polyethers and amines of titanocene and polythioethers of zirconocene was also reported using similar methodologies (32,33). 

A series of organotin polyesters, polyethers, polyamines, polythioethers, poly-aminoesters, and polyetheresters (207-212) have also been prepared by reacting dialkyl (or Z>w-alkoxycarbonylalkyl) dichlorides with (1) organic dicarboxylic acids, (2) diols or diphenols, (3) diamines, (4) dithiols, (5) amino acids, and (6) hydroxy acids as shown in Scheme 53. ... 

Following are some structures that exemplify products that will be encountered in this review. The polyamines (structures drawn with a dibutyltin central moiety 1), polyethers, 2, polythioethers, and other related polymers feature a tetrahedral tin. 

In addition to polysubstitution, the polyaddition reaction can be used for synthesis of LC polymers. It is an alternative method for obtaining simple LC polyethers and their analogs—polythioethers and polyimines. Easily soluble LC polymers with a low molecular weight were obtained with the Michael reaction between mesogenic diacrylates and diamines or dithiols (in solution, at a temperature under 60 C) [21] ... 

Some are synonymous or near synonymous, e.g., poly alkeny lenes and polydienes, polyalkynylenes and poly acetylenes, polyethers and polyoxides, polythioethers and polysulfides. 

Heat-SensitiZingProcess. Another process used to make latex mbber articles of thicker section involves sensitizing the compound so that it coagulates when heated to a given temperature, then using heated molds to build the article to the desired thickness. Ammonia-preserved latex is used in this process, and polyether, polythioether, or poly(vinyl methyl ether) (PVME) can be used as heat-sensitizing agents. 

Of the many other aliphatic polyethers, polythioethers and polysulphides prepared in the laboratory, some have become commercially available. Those of interest to the plastics industry are dealt with later in this chapter. 

E. M. Fettes and F. O. Davis, in N. G. Gaylord, ed., Polyethers, III, Polyalkylene Sulfides and Other Polythioethers, Interscience Publishers, New York,... 

Although polyethers are the main building blocks of the prepolymer, other materials such as polyesters, polythioethers, and polybutadienes are also used. Most urethanes use blends of polymers to achieve desired properties. Urethane sealants have pood inherent adhesion to most substrates, but silane adhesion promoters are often used to unprove this adhesion,... 

A wide variety of group 4 (Ti, Zr, Hf) metallocene-containing polyethers, polythioethers, polyesters, polyamines, polyoximes, and polyamidoximes has also been reported. Their synthesis, which is based on the polycondensation (with HCl elimination) of CP2MGI2 with difunctional organic species such as diols, dithiols, etc. (Scheme 14), was carried out either in aqueous solution or using interfacial condensation techniques, based upon the... 

Aromatic polythioethers or polysulfides are closely related to polyethers in structure and properties. A typical aromatic polysulfide is poly(phenylene sulfide) (PPS) (20), which is used as electrical insulators and structural parts in the building of engines and vehicles. Poly(phenylene sulfide) is prepared by the condensation reaction between /7-dichlorobenzene and sodium sulfide ... 

These indude polyethers, polythioethers, and polyamines [82-85]. In addition to linear materials, star-shaped polymers such as 4.39 have been reported [86]. These materials are redox-active as a result of the presence of the cationic ArFe(i/ -CsHs) moieties, which undergo reversible reduction at -40 °C. The materials are photo-... 

The majority of the structures is prepared from AB2 monomers by polycondensation, to result in hb polyesters, polyamides, polyethers, poly(ester amide)s, polysulfones, poly(ether ketone)s, polyphenylenes (among others), and increasingly also by polyaddition leading to, for example, poly(carbosilane)s, poly(urea urethane)s, polyarylenes, poly(ether amide)s or polythioethers, and many others [6-11, 13, 17, 21]. In particular, cycloaddition reactions offer the advantage of an often very selective and clean, high-yield reaction that is not influenced by special functionalities [33]. The relatively easy synthesis of the hb polyphenylenes described by Mullen et al. [34]. is an excellent example of this. In addition, certain cycloaddition reactions form as Hnear units nonstable intermediates, which allows the preparation of hb polymers without any linear units, which therefore exhibit formally a DB of 100% [35]. 

GAYLORD, N. G. Polyethers. Ill Polyalkylene Sulfides and Other Polythioethers. New York Intersdence Publishing Co., 1962. 

Polythioether dendrons, the sulfur analogues of the poly(aryl benzyl ether) dendrons, were assembled by Portnoy and coworkers to the fourth generation. These dendrons were prepared using the protected thiophenol monomer building block, which can be efficiently synthesized from the hydroxy isophthalate diester in multigram quantities. The deprotection of the thiophenolate performed in situ is followed by three steps (similar to those previously described for the polyether dendrons in Scheme 15.17b) for each generation assembly (Scheme 15.20). ... 

Polyethers, Part III - Polyalkane Sulfides and other Polythioethers, Ed., N.G. Gaylord, Wiley-Interscience, New York, NY, USA, 1962. 

Gaylord NG (ed) (1%2) Polyethers, Part IIL Polyalkylene sulfides and other polythioethers. Intersdence, New York, p 1... 

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