This, however, requires that the amine group containing compounds and the resultant polyether polyols be produced in the same plant or nearby plants, with little to no time lapse between the point at which the amine containing compounds are distilled and when these are used as initiators to form polyether polyols.
In accordance with the present invention, suitable compounds for treating aromaticamines to prevent discoloration are compounds including alkali metal salts of sulfur compounds, hydrates thereof, and aldehydes thereof; aluminum hydrides; borates; and boron compounds.
Suitable aromaticamine group containing compounds include, for example, those compounds wherein at least 1 amine group is, preferably 1 to 3 amine groups, and most preferably 2 amine groups are attached directly to an aromatic ring, and the aromatic ring may be substituted or unsubstituted.
In a chemiresistor of the present type, the film is made of a poly(aromatic amine), the resistivity of which decreases upon exposure to acids in both the vapor and aqueous phases.
In addition, the color of a poly(aromatic amine) varies with the acidity of its environment; thus, in principle, one could deposit a poly(aromatic amine) on the end of an optical fiber and monitor the concentration of acidic gas by measuring the optical absorption spectrum from the opposite end of the fiber.
Of the poly(aromatic amine)s, polyaniline is especially attractive, not only because it has suitable physical and chemical properties, but also because its monomer is relatively inexpensive; thus, it should be possible to manufacture relatively inexpensive (even disposable) sensors for deployment over large areas and for personal monitoring badges.
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