Derivatives of Isophthalonitrile (IPN) like /77-xylylenediamine (MXDA) CH2NH2
and 1,3-bis(aminomethyl)cyclohexane (1, 3-BAC) CH,NH I M I I2 2
CH2INH M I 12 2
. . . can save you research time We've synthesized valuable derivatives of IPN like MXDA and 1.3-BAC that could take you one step closer to a commercially valuable chemical and save you research time. A host of new applications can be developed for MXDA as a building block for synthetic fibers and organic chemicals for a variety of uses. 1.3-BAC is a 50-50 mixture of cis-trans isomers and has potential applications similar to those of MXDA. Technical literature is available by writing: The Sherwin-Williams Company, Chemical Division. 11541 S. Champlam Ave.. Chicago. IL 60628. Attention: W. J. Banke.
SHERIllin
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CHEMICALS e 1980-The Sherwin-Williams Company
C&ENAug. 11, 1980
an equal volume of reference fluid to the other. The two fluids form a liquid junction by capillary flow through the strip of ion-free paper, which replaces the traditional "salt bridge." The paper bridge is coated on both sides with polyethylene to inhibit evaporation and confine the fluid flow to the desired course. A potentiometer connected to the electrodes measures the potential difference. This information is transmitted to the microprocessor, which calculates and displays the potassium concentration of the patient's serum. The other potentiometric assay slides are constructed similarly. In the chloride-selective electrode, however, there is no ion-selective layer. Instead, the Ag/AgCl bilayer is coated with cellulose acetate to protect the electrode from substances that will react with silver chloride. Unlike conventional electrodes, which require presoaking in buffer solution, Kodak's multilayered ionselective electrodes require no preconditioning. In practice, a stable potential is reached within three minutes after the serum and reference fluid have been added to the electrode. Kodak says its new Ektachem 400 analyzer won't be available until spring 1981. And initially the instrument's availability will be limited to areas of the U.S. where Kodak sales and service personnel are located to provide customer support. D
Promising process for synfuels' by-products
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Some of the dye-forming reactions currently utilized in the slide assays are based on standard wet chemical clinical assays, says Dan Shilt, who coordinates Kodak's markets programs. But other reactions were newly devised. Kodak now is trying to extend its multilayer assay technology to other blood components. Ionic constituents of electrolytes also can be assayed, but these require Kodak's disposable potentiometric slides. These consist of two thin-film, multilayer, ion-selective electrodes connected by a paper bridge—essentially a miniature electrochemical cell in a plastic mount. The potassium-selective electrode slide, for instance, consists of four layers that are built up sequentially on the plastic support. The bottom layer is silver. A chlorochromate oxidizing bath is used to convert the upper half of the silver layer into a silver chloride film. The resulting Ag/AgCl electrode then is coated with an aqueous gelatin solution containing potassium chloride; this layer serves as the internal reference and establishes the Ag/AgCl electrode's potential. Finally, an ion-selective layer of polyvinyl chloride, plasticizer, and valinomycin is deposited on top. Valinomycin is a commercially available ionophore that selectively allows only potassium ions to pass through the top layer. One drop (10 microliters) of blood serum is applied to one electrode, and
An expected generation of shale oil and coal gasification by-product liquids has prompted considerable development effort aimed at better utilizing these by-products in existing process trains. The ideal situation is simply to feed the by-products to existing processes without changing anything. One process that comes close is the Houdry Litol process for producing benzene from the light oils obtained from coking coal. Six Litol plants are currently in production around the world, and three more are in design or under construction. Total capacity of the nine plants will be 180 million gal per year of benzene. U.S. production is about 1.5 billion gal per year. Adapting to newer feedstocks from a synfuels industry does require some process modification, and it may cause problems in neighboring product areas. According to William A. Schwartz, supervisor of process engineering for Houdry's parent company, Air Products & Chemicals, the principal feedstock for the conventional Litol plant is the CQ to Cs liquid
fraction from the coking ovens. The benzene also can be derived from this feedstock by acid treatment or by hydrogénation and desulfurization. These diminish the yield of benzene and produce some undesirable wastes, however. The Litol process purifies the aromatics from the light oil feed by hydrogénation of unsaturates, hydrocracking of nonaromatics, hydrodesulfurization, and dehydrogenation of naphthenes. The aromatics produced are selectively dealkylated to benzene. The Litol process has two catalytic reaction zones, a hydrogénation zone and a hydrocracking/desulfurization/dealkylation zone. The light oil feedstock is vaporized and contacted with a hydrogen-rich gas. This partially hydrogenated stream is heated to 600° C and passed through a fixed-bed reactor where the sulfurcontaining compounds are converted to hydrogen sulfide. Some of the naphthenes also are dehydrogenated to aromatics, nonaromatics are hydrocracked, and the alkyl aromatics are completely dealkylated.
Modified Litol process has additional reactor
