High Temperature-Resistant Polymers

In the 1960s, CIBA Products Co. marketed and manufactured glycidylated o-cresol novolak resins, which had been developed by Koppers Co. as high temperature-resistant polymers. Dow offered glycidylated phenol novolak resins, SheU introduced polyglycidyl ethers of tetrafunctional phenols, and Union Carbide developed a triglycidyl p- am in oph en o1 resin. 

FRAZER, A. H., High Temperature Resistant Polymers, Interscience, New York (1968)... 

As part of an effort to develop high-performance, high-temperature-resistant polymers for microelectronics applications, we also recently described a series of both partially fluorinated and nonfluorinated poly(aryl ether ketone)s containing amide, amide-imide, cyano oxadizole, or pyridazine groups and characterized their thermal and electrical properties.11... 

Many heterocyclic polymers have been produced in an attempt to develop high-temperature-resistant polymers for aerospace applications. Among these are the polybenzimidazoles (PBIs), which are prepared from aromatic tetramines and esters of dicarboxylic acids (structure 4.63). In standardized procedures, the reactants are heated to below 300°C forming soluble prepolymer, which is converted to the final insoluble polymer by further heating ... 

Frazer, A.M. "High Temperature Resistant Polymers" John Wiley Sons Inc. New York, 1968. 

Use Manufacture of polybenzimidazoles, high-temperature-resistant polymers. 

Aromatic polyimides have achieved considerable success as high temperature-resistant polymers. Since the desired high molecular weight polyimides are not readily processable, they are generated in situ by the thermal ring closure of the processable precursor poly(amic-acids) ( 2). The use of low molecular weight prepolymers, i.e. poly(amic-acids), as laminating resins is limited by their conversion to an intractable state before complete elimination of volatile by-products. 

C2BioHioSi(CH3)20SiR R"0— with molecular weights up to 250,000 . In a related study a high-temperature-resistant polymer is prepared from l,7-C2BioHio-l,7-[Si(CH3)20H]2 and (CH3)2Si[N(CH3)2]2 . A carborane-siloxane block copolymer with 1,7-C2BioHio units is prepared by the reaction of a ureidosilane-terminated polysulfone hard block with a carborane-silanol-terminated carborane-siloxane oligomer . 

Kroh M (2008) Development of a modified processing technique for selective laser sintering of high temperature resistant polymers with a Nd YAG-laser. Conference of the polymer... 

Lee H, Stoffey D, Neville K (1967) New Linear Polymers. McGraw-Hill, New York Frazer AH (1968) High Temperature Resistant Polymers. Wiley Interscience, New... 

P.E. Cassidy, Thermally Stable Polymers, M. Dekker, New York, 1980 J.P. Critchy, GJ. Knight, and W.W. Wright, Heat Resistant Polymers, Plenum Press, New York, 1983 A.H. Frazer, High Temperature Resistant Polymers, Wiley-Intersdence, New York, 1968. 

Polybenzimidazoles (PBIs) are high-temperature-resistant polymers. They are prepared from aromatic tetramines (for example, tetra amino-biphenol) and aromatic dicarboxylic acids (diphenylisophthalate). The reactants are heated to form a soluble prepolymer that is converted to the insoluble polymer by heating at temperatures above 300°C. The general structure of PBI is shown in Fig. 2.12. 

Nomex is a high-temperature-resistant polymer since it degrades without melting at temperatures in excess of 300 C. Furthermore, its outstanding mechanical properties are retained after prolonged exposure to elevated temperatures. Its melt intractability precludes melt spinning and it is produced by solvent spinning. 

As mentioned earlier, the growth of interest in high-temperature-resistant polymers has been mainly due to the need for these materials as adhesives and composites by the aerospace industry. But the utilization of heat-resistant polymers has been limited by the fact that these materials are often insoluble and infusible and therefore difficult to process. Hence, research during the past two decades has been mainly directed not towards attaining higher thermal stability, but towards the retention of as much stability as possible while introducing solubility or moldability (processibil-ity). It is this aspect of high-temperature polymers which is discussed in the next section. 

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