High-temperature polymers inorganic

Reviews containing substantial amounts of data on metallorganic ring-forming polymerizations were found under chelate polymers (7, 18, 23, 31, 33) coordination polymers (5, 6, 9-12, 19, 20, 22, 24, 32, 35) metallorganic polymers (J, 17, 25) and high-temperature polymers (/, 2, 4, 26,28). Reviews and books on inorganic polymers were also useful. 

Organic polymer materials may be analyzed by ashing at relatively high temperatures. This involves oxidation of the carbon containing matrix, leaving an inorganic residue that is taken up in acid. An alternadve in some cases is to dissolve the polymer in solvent and analyze the nonaqueous solution direcdy. Nonaqueous media will be discussed in a later secdon. 

A systematic study of this class of compounds did not start until twenty years later and led to the preparation of a series of M3Q7X4 (M = Mo, W Q = S, Se and X = C1, Br) inorganic polymers by high-temperature reactions (ca. 350 °C) of the elements in a sealed tube [10-14]. The interest on these cluster phases was mainly motivated by their excellent role as synthons for the preparation of molecular M3Q7 and M3Q4 cluster complexes, as will be presented in this section. 

Inorganic polymers based on alternating main group element-nitrogen skeletons (e.g. I - IV) are of interest for their potential as elastomers, high-temperature oils, electrical conductors, biological molecule carriers, and precursors to ceramic materials (J - 6). 

The PEMFCs require expensive polymer membrane (e.g., Nation ), and operate at a low temperature (e.g., 80°C). Although low temperature reduced the cost of material, the heat generated at low temperatures is more difficult to remove. Alternate proton conducting membranes (e.g., inorganic polymer composites) that will operate at a high temperature (e.g., 200°C) are required. The expensive platinum catalyst used for electrochemical reactions can be poisoned by even trace amounts of carbon monoxide in the hydrogen fuel stream. Hence, a more tolerant catalyst material needs to be developed. 

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