1940: Chemistry

Chemistry, both pure and applied, can be proud of its progress during 1940. While in some fields the accomplishments may not be so spectacular as in other years, others rank well with previous achievements.

Sulfanilamide and Its Derivatives.

For most of us matters of health and self-preservation still come first, and so we turn again to the spectacular results which have been obtained with sulfanilamide, and which are now being achieved with its increasing number of derivatives. The public has heard much about sulfanilamide and is inclined to pass over that word in the news—but not so the chemist. So far, more than fifteen hundred derivatives have been made, in the effort to find something better for particular applications, and especially some form or derivative of the drug that will be less toxic and at the same time more efficient in overcoming some infection. Beginning with sulfanilamide, we had an effective drug against the streptococcus type of invasion; then came sulfapyridine, with which to combat all the types of pneumococcus, which cause pneumonia; then sulfathiazole, effective even against the dread staphylococcus. Now another derivative gives great promise because with it the alimentary tract can be sterilized without enough of the compound getting into the blood stream to cause complications; and it is believed promising in still other fields of medicine. Another new derivative is a compound involving nicotinic acid, and the advantage claimed for it is effectiveness in reduced dosages, thereby avoiding the depression of the central nervous system that may be an undesirable effect of sulfanilamide on some patients. Late in 1940 a camphorated derivative was perfected, and for it, too, less toxicity than with the original drug has been found. Because of its high potency the dosage required is less than in the administration of sulfanilamide itself, and it has been found particularly effective in the treatment of pneumonia. (See also BIOLOGICAL CHEMISTRY; MEDICINE.)

Calcium Compounds.

Calcium is one of the elements essential to the maintenance of our bodies and in recent years much work has been done on forms easily assimilated in our metabolism. To calcium gluconate, now well-established in therapeutics, new calcium compounds were added during 1940.

Vitamins.

Vitamins still continue to hold their place in the scientific and public interest. One of the discoveries of the past year was that the form of blindness known as keratitis, a disease in which the cornea of the eye is invaded by a superfluous number of blood vessels, followed by the formation of white opaque spots that blot out vision, is caused by the lack of vitamin B₂ or riboflavin. Even more important was the discovery that the administration of this vitamin would clear up the spots and restore vision. Further, if the vitamin is administered in the early or incipient stages, it was found, the disease can be prevented from developing.

For a long time physiologists have emphasized the fact that in refining foods to meet the demands of modern diets, desirable vitamins are frequently lost, not to be recovered. A century ago when everyone ate whole-wheat bread this difficulty did not exist. It seems important, therefore, that foods can today be fortified by the addition of riboflavin or vitamin B₂, now available in large quantities and at a price so reasonable that it can also be added to stock feeds. It is produced by a new method involving the fermentation of starches and sugars. In Great Britain, where the people insist upon white flour, deficient in vitamins, bread will now be fortified with vitamin B₁ and a little calcium salt. It will be recalled that this vitamin, thanks to research in the United States, is now commercially available in whatever quantity may be required. Thus we find vitamins becoming available through the grocery as well as through the pharmacy.

Another source of vitamins is at least interesting and may soon become commercial. It was reported that edible vitamins are to be found in grass and that 12 pounds of dried grass contain more vitamins than 340 pounds of fruits and vegetables. All that remains is to perfect a method for drying grass without damage to the vitamins, so that it can be offered in a powdered form suitable for incorporation in foods. We have here an inexhaustible cheap source of these vital food factors.

Foods.

Foods will always have the attention of scientists. There is such a supply of foods new either in form or substance that a Food of the Month Club has been formed, offering to supply new items each month which the subscriber can try on the family.

One of the most important developments in the past fifty years affecting lard was the discovery during 1940 that its oxidation can be prevented. All that is required is the addition of an exceedingly small quantity of gum guaiac derived from a tropical tree. This preserves the linoleic constituents of the lard, a health factor of considerable importance.

Then it has been found that a little calcium chloride will stiffen canned tomatoes, so that they retain their shape and are consequently more attractive. The pure food regulations offer no bar to this procedure.

The turkey crop is more important year by year, but turkeys have their troubles, too. One of these is perosis, the name for slipped tendons. But if one pound of manganese in the form of sulphate is added to one ton of mash used as a feed for turkeys that are penned, the trouble is prevented.

Rubber.

A real headline for 1940 has been the development of so-called synthetic rubbers in the United States, and new progress in the use of rubber. Strictly speaking, these new materials should be called 'elastomers' or by some other name to indicate that they are not true duplicates of natural rubber. The molecules are not identical. But apparently the term 'synthetic rubber' has come to stay. What has been accomplished in rubber during 1940, the culmination of research begun much earlier, is probably from the point of view of applied science the most important development of the past year.

Synthetic rubber had been produced before, notably methyl rubber in Germany 25 years ago. However, it was disappointing in performance during the World War. Also prior to 1940 we had neoprene, Thiokol, and Koroseal, all American products available on a commercial scale and used because they could perform services impossible to natural rubber. For example, these materials resist the action of petroleum and its products far better than natural rubber; although they cost from three to six times as much, they have been in demand. Buna in different varieties, developed in Germany, has had much publicity and about half the requirements of the Reich had been met by this synthetic prior to the outbreak of the present war. Sovprene is the name of a similar product developed in the Soviet.

The announcements and introduction of new synthetic rubbers in the United States during 1940 were enough to afford an excellent example for those who contend that when things are badly needed inventors will produce them. Three new synthetic rubbers of American origin made their bow, all manufactured from raw materials to be had within this country: Butyl rubber is one, Ameripol another, and Chemigum the third. They are all products of gases derived from petroleum.

This is further evidence that petroleum, so long used only to produce fuels and lubricants, has become almost as important as a raw material for the chemical industries. If the United States is to embark upon a program for the manufacture of enough chemical rubber to make us independent of crude rubber, perfectly enormous quantities of butadiene made from butane, derived from petroleum, are essential. Butadiene can also be made from alcohol, as has been done in Russia, but petroleum is a more economical source. In addition, the patent rights to manufacture Buna, also from butadene, are owned here.

One should not jump to the conclusion that synthetic rubber is soon to be available in great quantity. Some 1,700 tons were manufactured in 1939, and with greatly increased production costs will be lowered. Compare this quantity, however, with the 592,000 tons of crude rubber used in the same year and some idea is obtained of what is involved in producing even an important fraction of so large a total. Further, it would be unwise to proceed with the construction of necessary facilities without the experience that comes from erecting one such plant, thereby learning improvements and avoiding costly mistakes in those to follow. The synthesis of this type of material is most difficult, and that it should have been accomplished in so many different ways at a time when the product assumes unusual national importance is indeed remarkable.

A rubber product, Pliofilm, found a new job in 1940, being used in the packing industry to prevent weight shrinkage. First used as a wrapper for meat loaves, it is now applied by means of a packaging machine to a wider variety of meat products.

Rubber advanced further into the printing industry in 1940 in the form of rubber printing plates on a Webb press. The new plates are particularly suitable for printing on corrugated or uneven surfaces or for high-speed work. They also make possible a 25 per cent saving in ink and a reduction of as much as 66 per cent in the time required for make-ready.

Rubber has also been introduced in a new type of armor plate, in which a special rubber alternates with thin steel sheets. The resulting armor resists bullet penetration equivalent to solid steel armor plate of 20 per cent greater weight. Weight saving is of course desirable not only in airplane armament but on the sea as well, and new applications are not impossible.

Metals and Their Applications.

Metals continually offer new opportunities, and these are by no means neglected. The sea has long been recognized as an inexhaustible mine for many materials. The plant of the Ethyl-Dow Chemical Co. at Wilmington, N. C., during four years of operation treated water equivalent to one square mile 354 feet deep or 634,366,000,000 pounds of brine. The chemicals in this vast amount were sodium chloride, magnesium sulphate or Epsom salts, calcium chloride, potassium chloride, aluminum, strontium carbonate, iron, copper, iodine, silver, and gold. If they could have been recovered and sold at current prices, they would have been worth over $383,000,000. In most cases, however, the cost of recovery would have been greater than their worth. The gold, 0.2 ton, was worth $168,000, but it would have cost more than that to extract it. Magnesium metal has become important, and in 1940 a $15,000,000 plant was built in Texas, to mine the ocean for this lightest of metals. The demand by aircraft construction is one of the reasons. The company has been producing about 2,500 tons of magnesium per year from the brines of Michigan. That amount has now been doubled, but with the completion of the new plant 12,500 tons will be the yearly production in the United States.

A new process for the recovery of aluminum from clay, the largest resource of this metal, has been announced. We now depend on bauxite, the ore which has always supplied us. If clay can be used successfully, it will indeed be fortunate.

Cable sheathing produced to the extent of $10,000,000 annually is ordinarily lead hardened with antimony, one of the strategic materials coming mostly from China. It has now been learned that calcium will harden lead, and the result is superior to the antimony lead. A smaller percentage of calcium than antimony is needed and there is less tendency for the alloy to crack after long use in cables.

A new type of dustless and sliverless copper was perfected during 1940 to meet the need of the electrical industry for a metal free of the imperfections of ordinary copper. Ordinary copper is held responsible for the penetration of insulation and for a considerable percentage of failures caused by short circuits. The new copper approaches the malleability of gold, has greater ductility than ordinary copper, draws easier, and is a better conductor of electricity.

A new nail was offered last year, made from rust-resisting Monel metal. These nails are provided with a number of grooves that so increase their holding power in wood as to give better service than wood screws. They are particularly intended for marine work where their rust-resisting properties are highly valued.

A new magnetic alloy of cobalt, vanadium, and iron, that can be drawn and rolled, also made its bow. Polonium, one of the radioactive substances, was incorporated to advantage in the electrodes of spark plugs, and the element indium was produced in commercial quantities and found to play a very important part in bearings and on other surfaces subject to friction.

Petroleum.

Among the developments in the petroleum industry should be noted the increased production of aviation grade gasoline, the award of a contract for a plant to produce toluene for explosives from petroleum, and a patent for the production of high quality gasoline from paraffin wax. This last is accomplished by the action of heat of 850° to 1,000° F. and a catalyst such as an acid-treated clay of the type used for decolorizing lubricating oils. Distillation follows and the yield of high grade gasoline is about 40 per cent. The possibility of producing gasoline from vegetable products and from seaweed was the subject of a paper before the American Chemical Society. The carbohydrate materials—that is, products rich in starch or sugar—are heated under pressure with limestone. There is no idea that the farmer will in future produce his own gasoline, nor is it possible for fuel produced by this process to compete with the low cost of gasoline from crude oil. However, it is contended that fuel can be made cheaper by such a process than by the hydrogenation of coal, which is the German method and which requires expensive high-pressure equipment.

By feeding oxygen into the intake air, it has been found that the power of Diesel engines may be increased 55 per cent for the few minutes required to help the take-off of Diesel-equipped planes. This can be done without detonation or undue strain, and means that the weight of the engine can be reduced by one third.

The advantage of using 100 octane gasoline for ordinary motor cars and busses has been stressed and experiments show a 55 per cent increase in mileage per gallon over the 70 octane now in use at speeds of 20 miles an hour. At higher speeds the gain is as much as 40 per cent. If the cost of manufacturing high octane gasoline were twice that of ordinary fuel, the economy would still be in favor of the better gasoline. The airplane demand is such, however, that it may be some time before the ordinary motorist can take advantage of this economy.

Color.

It is interesting that a chance discovery has revealed the fact that color-blind men in airplanes are able to see through all types of camouflage so far developed. Also, color photographs taken from plane at night will penetrate camouflage that might hide military objectives from ordinary reconnaissance photography. (See also PHOTOGRAPHY.)

Plastics.

Plastics have continued to make an enviable record. Vinylidene chloride, trade-named Saran, has crude oil and salt brine as its parents. The product as first manufactured consists of so-called fibrous crystals in heterogeneous arrangement. At this stage the plastic has only ordinary properties and a tensile strength of about 8,000 pounds per square inch. However, when the fibrous crystals become oriented into linear patterns, the resin takes on remarkable properties. The strength is increased to 60,000 pounds per square inch, accompanied by great flexibility. The new resin has high chemical resistance and has already found its place in fishing tackle, as a binder for abrasive wheels, and in extruded threads which, woven, have been used as seat covers in some New York subway car equipment.

New applications of plastics include furniture, ladies' shoes, football helmets, and costume jewelry. Veneers of expensive and rare woods are used not only to mold various pieces of jewelry but to provide decorative finishes for vanity and cigarette cases, table tops, baggage, and even wall panels. Interior walls of a room may now be had in one piece; and a wood veneer laminated with one of the synthetic resins is now provided in pieces up to 8 x 20 feet into which it is only necessary to fit window and door frames. Joints, cracks, and other features unsatisfactory for finishing are absent, and one side is provided with a cloth surface to facilitate the type of preferred adornment.

The use of plastics in molding airplanes has received much attention and a 2,050-pound, low-wing monoplane trainer was built. This was composed of triple laminated spruce plywood, impregnated with phenol resin plastics. The parts were made in molds and then baked under pressure. Riveting and welding are eliminated in such construction, and if the process can be applied commercially and the airplanes prove satisfactory in use, the production rate will be 20 times faster than for metal aircraft. At least four aircraft companies and two research laboratories are working on this problem. (See also PLASTICS.)

Glass.

Much interest was aroused in 1939 in the possibility of increasing the transparency of glass by giving the surface a very thin coating. The first commercial application was in projection lenses, where the utmost light was desirable with colored movies. The difficulty with that development for show windows was the nonpermanent character of the film. This objection has been somewhat overcome by the most recent developments. Meanwhile a new method has been introduced in which, instead of treating the surface of the glass to form a thin film, the oxides in the glass surface are dissolved from a very thin layer. This has been found possible without damage to the surface polish, just so long as the solvent does not take out the silica. Telescopes, and photograph lenses are likely to be the first beneficiaries.

A new glass has been devised for use with X-rays. It is laminated with the center of the sandwich a piece of glass high in lead oxide. Progress was also made in the manufacture of mirrors. Spray methods for applying the silvering solution were perfected, with higher quality and lower cost two of the results. The process is continuous, with no manual handling involved.

Pulp and Paper.

In the paper field the use of new species involving some change in the chemical processing of the pulpwood potentially added much to our resources. It was found that contrary to accepted ideas, white pine can be grown as rapidly in New England as loblolly and slash pine in the South. Improvement in bleaching pulp, using sodium chlorite, now available commercially, is expected to make the United States independent of Scandinavian wood pulp. This chemical compound, commonly called chlorite, has the unusual property of bleaching wood pulp, cotton, rayon, and other materials extremely white without weakening the fibers or causing the loss of other desirable properties.

Improvements in bleaching what is called sulphate pulp, now made in great quantities, make it possible to replace sulphite pulp in some papers. This again broadens the resources from which pulp satisfactory even for ledger papers may be made, and the strong sulphate pulp can compete with sulphite in the production with ground wood of newsprint. (See also PAPER AND PULP INDUSTRY.)

Containers.

The tin situation, as well as continued competition in the container industry, has led to further developments. Reports are that there is not more than a year's supply of tin in the country, and it may be some time before tin is refined here. Further steps have been taken in the use of plastics or synthetic resins to line cans of untinned iron which are generally decorated with aluminum paint, producing a can satisfactory for many purposes. New designs of glass bottles, in which a stronger glass is used, have made possible the competition of the bottle with the single-service fiber container and even with the can.

A container of Pliofilm and cellulose acetate has been introduced for food products. This is a light-weight transparent package held in a cardboard carton and presents advantages of its own as a single-service package.

Paints.

Progress continues in the field of protective coatings and methods for their application. The effort continues to produce paints of germicidal value, and it is known that a halogenated oil containing 4 per cent chlorine, when added to linseed oil for paint, possesses the highest germicidal value, but even this is not great. New paints were introduced for rooms with health lamps. Most paints reflect less than 10 per cent of the ultraviolet light from such lamps, but a new one was introduced that will reflect up to 72 per cent of these beneficial rays.

Most paints, lacquers, and the like are applied with the help of a vehicle. This, of course, introduces drying problems, which vary with the type of coating employed. More enamels are being used than formerly, such as on reflectors and even automobiles. Infrared rays, which are the heat rays of the spectrum, are now applied commercially, using old-style carbon filament lamps with gold-plated reflectors, so that an automobile may almost be said to proceed through a gold-lined tunnel as the finishing step in its decorated exterior. A new enamel called Ethomelt avoids the use of vehicles altogether and is applied hot.

Textiles.

Nylon made its commercial bow in May and the stock of women's hose that had been accumulated for the event was cleaned out of most stores in a few hours. Since then there has been difficulty in maintaining stocks. It is well to remember that the women of America use 50 million dozen pairs of silk hose annually, and that the nylon fiber available could account for somewhat less than 10 per cent of that number during 1940. However, new facilities for producing the fiber have been under way and a new plant is in process of erection, so that by the end of 1941 or early in 1942 five times the originally planned output of fiber will be made, some 16,000,000 pounds annually. And there will be represented in equipment for the manufacture of nylon fiber some $28,000,000. Notwithstanding this demand, a price reduction in nylon yarns was made in October, in conformity with the policy which exists in the chemical industry to reduce prices as rapidly as large-scale production makes it possible.

Improvements in nylon have been announced. It has been made tougher and stronger by a tempering process—more important in the case of bristles, films, and rods than of fibers used in hosiery. The tendency of the fiber to darken when subjected to heat and light has been overcome by a new process, and a derivative of the first material has been made resistant to long contact with acids and alkalies. Another advance has been to render nylon permanently waterproof, so that stockings made from it are splashproof. Open-toed shoes put added stress on stocking toes, and now the hosiery can be reinforced with nylon-covered elastic toes. The versatility of nylon is further demonstrated by its use in photographic film, where its great strength enables thinner film base to be made and with much longer service life. Wool-like fiber of nylon is made, and still other forms are possible. Vinylidene chloride, mentioned elsewhere, is also a fiber base, and a competitor named Fortezan is in the offing. The latter is said to be stronger and more elastic than the first truly synthetic fiber.

The fiber produced from the casein of skim milk, first publicized in Italy, and now made here, was used as a supplement up to a maximum of 10 per cent with rabbit fur to make high quality hats. This came at a time when the importation of rabbit fur was disturbed by the war. It is said that between one and two million pounds of such fiber will be required annually for hat making. It is interesting to add that material for a woman's dress requires casein from thirty quarts of milk. There has been further work on similar fibers from the protein in soybeans, and cloth containing 30 per cent of this fiber with 10 per cent of mohair and 60 per cent of wool has been made for upholstery in automobiles.

A new method for mercerizing cotton fabrics, so that the material has a high sheen and a soft feel and is practically shrinkproof is now utilized. Improvement in mothproofing is reported. The new process holds the proofing reagent chemically bonded to the wool and the fabric can be repeatedly laundered without losing its moth-resistant properties. Just as mothproofing agents are made a part of the fiber, a patent has been issued covering the precipitation of synthetic resins within a fiber of cellulose acetate yarn to increase its resiliency and render it substantially creaseless.

A carpet that glows in the dark has been developed for sleeping cars, theaters, and other partly illuminated places. Dyes that absorb invisible ultraviolet light and reflect it as visible light are the secret of this material. The dyes are used to treat the wool before the carpet is woven and the details of the pattern stand out strikingly. Special lamps fitted with filters allow only invisible ultraviolet rays of the light to pass. Concealed in the ceiling and walls, they are not seen by patrons. Greater safety and the elimination of shaded aisle lights are other advantages. (See also TEXTILES.)

Other Developments.

To the multitude of uses to which synthetic resins have been put, add water softening. So far this work has been done with water which is not very hard. The investigation of course continues, and perhaps some day we shall see sea water made useful in household and industry by some such process. Synthetic resins also are employed to add strength to paper, especially when it is wet. We think first of paper towels in this connection, but there are other applications and the paper that is strong when wet will display even additional strength when dry.

An innovation in ink has been the introduction of a solid ink, one that is applied without oil or other vehicle and sets up without striking through the paper when cold.

Whey is a by-product in the manufacture of cheese. It may now become a raw material for a new type of wine. Yeast and sugar are used with the whey and the result, a type of Sauterne, improves with aging in the wood and clarification is helped by a cold shock. The new whey wine can also be produced in sherry flavors and contains 15 per cent of alcohol by volume.

It has been proposed that to protect ships' hulls from rust and barnacles the hull be submerged in water containing magnesium and calcium salts in the proportions in which they are found in sea water. Electric current is then passed through the water, so that the hull becomes the negative electrode. This would cause a coating of calcium and magnesium to be deposited on the hull. These coating are said to prevent the corrosion of the underlying steel and to make it more difficult for barnacles and other growths to establish themselves.

Colchicine helped produce the first new flower ever created by the use of a chemical—a tetra marigold. The new plant, 2½ feet high, bears very deep orange flowers, much larger than the parent flowers. The chemical has also been shown to have a beneficial effect on such trees as aspens and larches, trebling their size in young plants. Bigger trees mean more wood and cellulose for industry.

Riboflavin made eggplant grow faster and larger, while synthetic vitamin has caused unusual gains in the growth of tobacco. Tests with vitamin B₁ failed to prove that vitamin to be as useful with plants as some had claimed.

A new explosive prepared from butadiene derived from petroleum and ozone, a special form of oxygen, was announced. Another innovation is the use of water in place of explosives in some coal mines. Tubes covered with metallic braid are inserted in drill holes filled with water, which is then compressed to expand the tubes. This expansion breaks the coal and the hazards of explosives are avoided, as is the danger of gases resulting from explosives. The tubes are good for 2,500 tons of coal before they break.

The above citations are only indicative. The story cannot be made complete, nor can we give full details to show just how important some of these accomplishments have been. The emphasis now is on problems important in national defense.