Chemical Substitutes-War and Postwar N A RECENT discussion of this subject, Mr. William Howlett Gardner, Chief of the Chemical Materials Branch, Conservation Division, \VPB, made some in teresting observations. Although war's demand for raw materials has often exceeded our supply, our development of alternate substances and processes has made it possible for American industry to maintain production at a steady pace. Although they were originally adopted as an emergency measure, many of the substitute materials have proved so successful that they will have a lasting effect on postwar production. The part that chemical substitutes played in providing new materials when our foreign sources of supply fell to the enemy is well known. Their effect on our shipping program, however, is not generally recognized. If it had not been for our ability to interchange many domestic materials for unobtainable foreign imports, our military supplies would have been s~riously limited. Wide publicity has been given one of the largest chemical substitute programs-that of synthetic rubber. Many of the synthetic rubbers have physical and chemical properties, which, for certain uses, cannot be matched by natural rubber. In specialized military uses the demand for certain types of these rubbers has been as great as for natural rubber. Nylon, another chemical substitute, has replaced silk for most military applications, freeing our limited stocks of natural silk for use where no effective substitute is available. At first, nylon bristles were used as a substitute for hog bristles, which have been a particularly troublesome problem in view of the great need for paint brushes in coating ships. However, mili~ tary demands for nylon textiles have placed limitations upon its use for this purpose, making it necessary to supplement our bristle stocks with hog bristles flown out of. China, and with horsehair. Recently, however, the Eastern Regional Labora~ tories have developed a casein fiber which holds great promise as a substitute. The loss of the major source of supply for copra and palm oil has resulted in the use of synthetic detergents in the production of salt water soaps. With these synthetic substances the Armed Forces were able to carry out washing operations that might have been impossible with high lauric acid types of soap. As a result, it has been possible to allocate limited quantities of high lauric acid oils for civilian needs. Tremendous savings in shipping bulk and weight have also been effected through the use of these synthetic materials. Linseed oil requirements have been met by developing a large American flax crop. Thus, we have been able to serve not only prewar uses such as linoleum and paint, but also to furnish a new source of food supply for our Russian allies. The Government purchased vast quantities of linseed oil for this latter purpose. Contrary to what one might surmise, linseed oil has proved to be a suitable substitute for other scarce oils used in shortening. Japanese blockade of Calcutta, the sole port of export for shellac, would have seriously handicapped the war effort if it had not been for the development of highly improved spirit varnish replacements. Today several importers are selling more of the substitute than they ever did of shellac varnish. The development of synthetic wool is already relieving the shipping strain on natural wool imports. Several large synthetic cryolite plants were constructed at the beginning of the war as a security against Gennan submarine action's cutting off our supply from Greenland. Plywood. has partially relieved the demands for mahogany from Central America and Africa. Plastics replaced aluminum when the Caribbean submarine menace made bauxite importation difficult. These are but a few of the endless number of important examples which can be cited as having played a part in getting supplies to our Armed Forces.
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Needless to say, agencies such as the Office of Economic Warfare have becn scouring countries to our South, as well as all parts of the world outside of enemy hands, seeking new sub· stitutes to augment those we have been able to produce domes· tically. The discovery of Garcia nuts in Mexico and South America will some day give us new drying oil even superior to tung oil for paint and varnish manufacture. Foresight in establishing the tung oil industry before the war in Florida, . Mississippi, Louisiana. and Texas despite the cheap labor of the Orient, has yielded encouraging returns. Until the Burma Road is again opened we are entirely dependent UpOll domestic supplies of tung oil and synthetic substitutes. \Ve have been surprised to find in how many instances the substitutes have proved superior to the materials commonly used. This is partially due to advances in technology and improved methods of fabrication and partially to unique properties of the substitute materials not fully appreciated before the war. Por example, in developing a plastic bugle to conserve brass, it was found that even at Arctic temperatures the new instru. ment can be blown without warming up the mouthpiece. Military raincoats and other protective articles made from textiles coated with vinyl resins are much lighter than anything ever made with rubber. Now that synthetic rubber is available for such purposes, new problems arise in trying to match the properties of the nonrigid plastics! Similarly, laminated wood bonded with synthetic resin has all the necessary properties of the metals for certain uses for which it was substituted. Corrosion is not a factor in using wood. Hence, there will be little tendency to revert to metals 'for such applications even if metals become more readily available than plywood. Clothing treatcd with water repeIlants was originally developed as a means for saving rubber. Such garments permit greater ventilation through the clothing than the ordinary types of waterproof garments. It has been found that troops will abandon raincoats in favor of moisture-proof clothing in the tropics even during the monsoon season. The postwar comequences of these substitutions upon in~ dividual industries will not be as serious as might appear from the above. Competition from new substitutes is a common occurrence under a peacetime economy. If we can judge. from what has taken place in the past, the nation need have no particular fear of the impact of these war measures. The introduction of substitutes under a normal economy invariably serves to expand an industry to the extent that there is an increased rather than a decreased demand for the original material. Certain wartime replacements for individual end uses may well be, therefore, complete and permanent, but new uses for the older materials will more than compensate for these losses. Time and time again, research has supplied the answer to maintaining a balanced economy. Take, for example, the shellac industry. In 1900, shellac moldings were introduced as a substitute for hard rubber for electrical insulation. Shellac at that time was much lower in price than rubber. Although this development might have had an initial adverse effect upon hard rubber production, the rapidly expanding field of electrical applications increased the demand for both rubber and shellac. Baekeland developed phenol~fonnaldehyde resins in 1908 as a substitute for shellac for the same purpose. What was the net result of this development? The new synthetic resins were found to have rapid thermosetting properties not possessed by the imported material. This led to the development of a large new field of molded organic plastics and to expanded uses for shellac. For although shellac could not compete with phenolics for certain applications, it was soon found that no other material would serve as insulation for high~voltage transmission. (Continued on page 129)
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MARCH,
129
1944
• A new translucent "skin" for protecting machine parts in shipment shows definite indications of relieving another bottleneck in the flow of new and replacement parts to the battlefronts, say Army Ordnance men. The new packaging material, recen tly developed by The Dow Chemical Company in response to an appeal from a maker of amphibian vehicles. is already saving time and manpower at home, and speeding the work of assembly and repair crews at the front. The product, which bas an ethy1cellulose base, is a plasticlike substance which is applied by a simple hot dip process; sets into a tough, skin-tight coat in a few seconds that fully protects the metal from rust, corrosion, and dirt during shipment. Assembly crews find it strips off quickly and easily with no more equipment than an ordinary pocket knife. Although the material used is not yet available for general distribution, being under rigid government control, production experts believe it will eventually revolutionize this entire phase of packaging procedure for civilian as well as military equipment. Previous methods frequently required the slow and laborious hand-wrapping of parts in a special greaseproof wrapping material followed by dipping in hot wax, or an alternative process of precoating the parts with a heavy grease which was difficult to remove in the field. These grease-coated parts likewise had to be hand-wrapped before shipment. The types of parts which can be treated by the new process are not yet completely defined. Its use is already apparent in many cases. Adaptations of method are constantly being extended under rigid military supervision. Actual production costs, ordnance men declare, already indicate packaging time reductions up to 80 per cent.
IVesli'lgJzOllSe Pholo LAMP TO PROTECT EGGS, TEST COLORS
Ultraviolet radiations from the coiled quartz tube, mercury vapor lamp transmute oxygen in the air into ozone.
WHAT'S BEEN GOING ON (Co"'i,,u,d[rom pag' 106) Cellulose nitrate lacquers were introduced in 1920. For a while it was felt that they might completely replace shellac as a rapid-drying varnish. Here again the new materials were destined to develop into a large industry. The use of shellac as a rapid-drying coating continued to iilereasc all through the twenties as the public became morc and more conscious of its advantages. So the two materials did not become truly competitive. Typical of a material in an entirely different field is rayon, first developed as a possible substitute for silk. It soon developed, however, into a more or less nOllcompetitivc industry of its own. Numcrous improvements have been madc in thc manufacture of materials during this emergency. Some of these developments will lead to marked reductions in cost and expanded lise during the postwar period. Improvements made in rock wool, for example, will bring about not only greater use of this material, but of insulating materials in gcneral. Many people realize for the first time how much fuel can be conserved by proper use of heat insulation. The greatest impact to old established industries during the period immediately following the war will not corne from wartime substitutes, but from new developments which have
been held back so far, due to other needs for raw materials. Advances made in synthetics for combat use will bring greater durability to postwar products. Lightweight material and plastic appliances will lighten the hour;ewife's burden. A wide variety of frozen and dehydrated products will cut down the time and effort required in food preparation. Once she has used the newly developed war potato flour, for example, the housewife will never want to make mashed potatoes any other way. She will also be able to obtain au all-year-round variety of products which before the war wcre prohibitive in cost during the off seasons. • War accomplishments ill the field of medical science and in the manufacture of products for increasing our health and safety will cut down loss of life and limb in the postwar period. Highoctane gasoline will increase our mileage and the life of our transportation vehicles. New dcvelopmellts in glass and ceramics will provide many products which we did lIot have before. New laboratory tools and methods of fabrication, such as the electron microscope, infrared drying mcthods, induction heating, and thc like. should eventually reduce the cost of manufacturing both the old materials and the newer substitutes. Hence, we can expect a greater Humber of products to be available to a wider purchasing public.
