Miscellaneous condensation polymers

Several papers concerned with the photodegradation of aromatic condensation polymers indicate that thermal stability and photostability are usually not displayed by the same polymers. The mechanism of photodegradation has usually not been established. 

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Miscellaneous Applications. Ben2otrifluoride derivatives have been incorporated into polymers for different appHcations. 2,4-Dichloroben2otrifluoride or 2,3,5,6-tetrafluoroben2otrifluoride [651-80-9] have been condensed with bisphenol A [80-05-7] to give ben2otrifluoride aryl ether semipermeable gas membranes (336,337). 3,5-Diaminoben2otrifluoride [368-53-6] and aromatic dianhydrides form polyimide resins for high temperature composites (qv) and adhesives (qv), as well as in the electronics industry (338,339). 

Finally, a few miscellaneous compounds which were identified in the Delaware River and which have not been previously reported as water contaminants will be discussed Chloro (trifluoromethyl) aniline and chloro (trifluoromethyl) nitrobenzene (no. 55 and 56) were identified in the water, they had maximum concentrations at river mile 78. Both compounds represent common sub-structures in various pesticide and dye molecules, and several of the companies located along the river have patents using these compounds (30-32j. It is possible that these compounds are actually present in the river water as such, but it is also possible that they are formed in the GC injection port by pyrolytic degradation of larger pesticide or dye molecules (see above). All three binaphthyl-sulfone isomers (no. 92) were identified in the river water near Philadelphia. Product literature for one of the companies in the area indicates production of condensed sulfonated polymers derived from naphthalene sulfonic acid and maleic anhydride. It seems likely that the binaphthylsulfones are formed as by-products during preparation of this commercial product. 

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