Polytriazole

A considerable number of non-cross-linked aromatic and heterocyclic polymers has been produced. These include polyaromatic ketones, aromatic and heterocyclic polyanhydrides, polythiazoles, polypyrazoles, polytriazoles, poly-quinoxalines, polyketoquinolines, polybenzimidazoles, polyhydantoins, and polyimides. Of these the last two have achieved some technical significance, and have already been considered in Chapters 21 and 18 respectively. The most important polyimides are obtained by reacting pyromellitic dianhydride with an aromatic diamine to give a product of general structure (Figure 29.17). 

Research Focus Single-step synthesis of poly((4-phenylsulfonic acid)-1,2,4-triazole)-c >-oxadiazole containing at least 85% polytriazole. 

The formation of triazole rings by the reactions of azides and acetylenes was first described by Huisgen and coworkers [48,49] and has recently been promoted as dick chemistry by Sharpless et al. [50,51]. This versatile [3 + 2] dipolar cycloaddition proved to be useful for the synthesis of hyperbranched polytriazoles via 1,3-dipolar polycydoaddition of AB2-type monomers 28 and 29 (Scheme 14) [52], The monomers exhibited very high reactivity the... 

C. Three Heteroatoms 1. Three Nitrogen Atoms Polytriazoles ... 

The action of diamines or aminotriazoles on 1,3,4-oxadiazoIes (Scheme 100) is a synthetic route to bistriazoles such as (219) and (220) (68JPR(309)168). Bistriazole (221) formation combined with alkylation of the resulting triazolinone (c/. Scheme 95) can make use of glycols instead of monohydric alcohols (68KGS372) as in Scheme 101. Related polytriazoles with aromatic links have also been prepared (81HC(37)1, p. 576). 

Of particular interest are the ladder polytriazoles formed from bisamidrazones with di-and tetra-carboxylic acids or bisbenzoxazinones, e.g. Scheme 149. Such polymers derived from napththoic acids have a high average molecular weight, high thermal resistance and good resistance to wear. 

The transformation of polyoxazoles and polytetrazines into polytriazoles are analogous to transformations treated under Section 4.12.4.3. 

Finally, mention should be made of polytriazoles formed by 1,3-addition reactions of dicyanides with bisnitrilimines conveniently generated from bistetrazoles. The polymers prepared from 1,3-dicyanohexafluoropropane were thermally stable but had a low degree of polymerization. 

Detailed tables of 43 polytriazoles will be found in (B-72MI41202). 

Hensema ER, Boom JP, Mulder MHV, Smolders C A. Two reaction routes for the preparation of aromatic polyoxadiazoles and polytriazoles syntheses and properties. J Polym Sci Part A Polym Chem 1994 32(3) 513-25. 

Gebben B. Thermally stable and chemically polymer membranes-aromatic polyoxadiazoles and polytriazoles [Ph.D. thesis]. Enschede, Holland Twente University 1988. 

Dipolar additirais of bisnitrileimines (generated from tetrazoles with dienes or with di nitriles) result in formations of polypyrazoles and polytriazoles [200]. Some examples of these reactions are ... 

Oxamidrazone is produced from dicyanogen and hydrazine. After isomerization with terephthaloyl chloride, oxamidrazone converts to poly-(terephthaloyl oxamidrazone) (PTO), which can be converted to a polytriazole, a poly(oxadiazole), or a metal-ion-chelating polymer ... 

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