PLASTICS – Modern Marvel of Science (Jun, 1939)
PLASTICS – Modern Marvel of Science
by John E. Pfeiffer
Science has learned the secret of converting natural gas. milk, acetates, ammonia and waste materials into useful products that enrich our lives. This is the third article of a series revealing their laboratory magic.
THE plastics industry crept up on the United States during panicky depression years. New that things have calmed down, people have time to look around a bitâ€”and everywhere they look, they see hundreds of plastic-made objects. The moldable rivals of metal, lumber, china, and such materials that go into the making of objects for your home and office, are all around you in various forms, including everything from combs to salt shakers. Jewelry using plastics is to be found in Tiffany’s as well as Woolworth’s. The old-fashioned bar with its wooden surface and brass rail is giving way to stylish bars made with a brilliant array of colored plastics. John D. Rockefeller has plastic-made panels for the bathrooms of one of his homes, and the great ocean liner the Queen Mary uses about $100,000 worth of the new industry’s best wares.
But Celluloid and cellulose acetatesâ€”the substances described in the previous article are by no means the only plastics used for these and many other purposes. The cellulose-containing materials are made from wood or cotton wastes and are examples of the so-called vegetable plastics. The field, however, also includes the mineral plastics, substances built from simple chemicals found in coal tar and in the air. Among these is the famous Bakelite, and the story of its finding makes one of the most interesting chapters in the history of synthetic chemistry.
Leo Baekeland was a promising student at the University of Ghent in Belgium. He had entered the institution in 1878 at the age of fifteen and when he graduated, became a chemistry professor. Young Baekeland wasn’t interested in the industrial application of his science, and would probably have been contented to teach would-be chemists for the rest of his life, had it not been for an unforeseen event. He fell in love with the daughter of another professor. No sooner was he married than he found two couldn’t live as cheaply as one. To support his wife the young man was forced to desert the classroom and devote his energies to solving the chemical problems of manufacturers.
Then in 1889 Dr. Baekeland did a bold thing. He left Belgium, went to the United States, and settled in Yonkers, N. Y. There in a small laboratory he performed many research tricks. His best bet at first, however, was a new kind of photographic paper called Velox, and he was just about to manufacture it on a large scale when the financial panic of 1893 ruined everything. For the next few years Dr. Baekeland had to endure a heart-breaking series of setbacks. Not only did he fall heavily into debt, but his health began to go back on him. Furthermore, the sick inventor was receiving complaints that his photographic paper was worthless. Careless customers blamed their failures on everything but their own ignorance. Finally, Dr. Baekeland decided it was too much trouble to manufacture Velox and at the same time teach buyers how to use it. One day he left Yonkers, traveled to Rochester, N. Y., and had a heart-to-heart talk with George Eastman, founder of the Eastman Kodak Company. What happened isn’t exactly known, but Eastman bought the young inventor’s paper, and the story is that Velox netted Baekeland a cool $1,000,000.
Whatever the actual amount transacted, it was enough to free Dr. Baekeland of the shackles of poverty, and give him time for other research. His struggle to live happily was over, but his greatest triumph was yet to come. In 1908 the great chemist was no longer a young man. But at the age of 45 he was more active than ever and hot on the trail of a new varnish. One day he mixed common carbolic acid (phenol) with formaldehydeâ€”a substance that stimulates plant growth. Then he heated the thick soup to about 400 degrees Fahrenheit. When the liquid cooled, it became hard and amberlike; furthermore, no amount of re-heating would cause the newly discovered phenolic material to get soft again â€”it was “thermosetting.”
Chemically speaking, the plastic’s proper name was “Oxybenzyl-methylenglycolanhy-dride,” but that tongue-twister would never do! Dr. Baekeland gave it the commercial nickname of Bakelite and proceeded to put it on the market. Years of bitter experience had taught the inventor an infallible lesson: “One of the evidences of a successful patent is infringement.” And Bakelite was no exception. Dr. Baekeland had to protect his phenol product from many imitators; he went through a flock of patent suits and won every one of them. The one-time professor had turned into a rare combination of top-notch inventor and shrewd business man.
If Bakelite is to be shaped by high-pressure methods or injected into forming molds, it is not allowed to become solid, but is ground into a powder before the hard, thermosetting stage. Or it may be poured in a lava-like stream into special molds and allowed to harden for a few days. Whatever the way manufacturers use to solidify Bakelite, however, it usually ends up with rich, lustrous dark colorsâ€”black, brown, mahogany, walnut. It can be treated in a host of waysâ€” asbestos can be added to increase its heat resistance, mica and graphite affects its electrical properties. Bakelite may be undamaged by temperature as high as 450 degrees Fahrenheit (lead melts at 327 degrees), and is a handy material for heating plugs, cooking-utensil handles, distributor heads in automobile engines, and permanent wave machine parts. Properly treated the phenolic plastic may be able to resist practically any amount of wear and tear. Football cleats are often made of Bakelite, as are silent gears for machinery. The mouthpieces and receivers of more than 17,000,000 telephones are constructed out of Dr. Baekeland’s top-notch money-making discovery. In 1926 his basic patents expired, and a host of other phenolic plastics were made. Besides the Bakelite Corp. in Bloomfield, N. J., leading companies and their phenolic plastics include the Catalin Corp. N. Y. (Catalin), General Plastics Inc., N. Y. (Durez), and many others.
But there is a fly in every ointment. The catch in the case of Bakelite, for example, is that it can’t be made in bright colors or white. In 1928 the Toledo Scale Co. needed a plastic with the latter color. Butchers’ scales must be white. Actual tests show housewives associate white so strongly with cleanliness that they won’t buy meat weighed on scales with other colors. So the Toledo Co. had to coat its cast-iron scales with gleaming white enamel, which often chipped and was an expensive process. Moreover, Toledo salesmen had to be small-scale Sandows, for some of their best scales weighed 165 pounds or more. What was needed was a permanently white material, lighter than cast-iron and as strong.
To find this substance the Toledo Scales Co. financed research work at Pittsburgh’s Mellon Institute. In two years the job was done. The new plastic came neither from plant matter nor coal tarâ€”it was made from gases in the air. Liquid ammoniaâ€”made with the air’s nitrogenâ€”is mixed with the gas you exhale, carbon dioxide, also in a fluid form. The result is urea, a white crystalline substance which is made on a commercial basis only at duPont’s Charleston, W. Va., plant. By properly mixing carbon monoxide (the automobile exhaust gas) with hydrogen, methyl or wood alcohol can be synthesized, and this liquid is mixed with plain oxygen to get formaldehyde (also used in Bakelite). When a special urea-formaldehyde combination hardens, it becomes a plastic which takes a beautiful clean white color. Squeeze the material at pressures from 1,500 to 6,000 pounds a square inch and out come new-style scale parts. The Toledo scales that once weighed 165 pounds now weigh one-third that figure, and the urea-formaldehyde plastic is strong and durable.
As a result of this work the Toledo Scales Co. started the Toledo Synthetic Products Co., which manufactures the urea-containing plastic as Plaskon (another company manufacturing such plastics is the Beetle Products division of the American Cyanamid Co.). To shape the new plastic for scales the General Electric Co. built a 160,000-lb., two-story-high press, and today this concern is firmly entrenched in the molding business. In this way the industry grows, and the urea-formaldehyde materials are used for many things besides butchers’ scales. Their smooth, weather-resisting surfaces become permanently hard when molded, and can be dyed in a wide variety of brilliant blues, reds, yellows and greens. In fact, these plastics in about 6,000 different shades are used to make clock cases, buttons and buckles, boxes for jewelry and perfumes, radio cabinets, and many other objects.
And the use of color is the main way plastics manufacturers hope to further catch the public’s eye. Other plastics that take color are the cellulose acetates and the so-called polystyrenes, materials that can be extracted from certain kinds of benzene. Hence, the psychological effect of color is an important consideration. Plastics experts have consulted color students and learned, for instance, that the following tints were among those supposed to suggest definite moods and feelings: red suggests heat, excitement, strength; brown is the utility color; yellow gives a sensation of airiness; light blue symbolizes coolness, fragility, youthfulness; dark green gives an impression of unhealthiness and cheapness; and lavender makes you think of fragrance and refinement. From this and similar information, plastics are being dyed not only for your practical needs, but also to appeal to your emotions.
Among the newest plastics are ones that may be colored or be completely transparent. There is the methacrylate plastic made at duPont’s Charleston plant from air, coal, and water. Out of these building blocks a substance is derived which, when hardened, is crystal-clear, light-transmitting, and only half as heavy as glass. It is called Lucite. The glare from window panes is due to the fact that ordinary glass reflects 8 per cent of the light that hits it. Lucite, however, only reflects about 5 per cent of the rays and hence produces a correspondingly smaller glare. Furthermore, while window glass doesn’t transmit health-bringing ultra-violet light, these beams slip through the remarkable transparent plastic without any trouble at all.
But whether or not Lucite ever replaces glass in your home, it has already found many unique applications. Besides Lucite’s use in making fancy candlesticks and other attractive objects, the plastic may prove a great aid to physicians and dentists. If you send light through one end of a tube-like piece of Lucite bent in the shape of an “L,” the light rays will act as if they were “piped.” The tube itself will glow a bit, but most of its light is held inside and comes out brilliantly at the other end. Few substances have the ability to bend light as well as this, and dentists’ instruments have already been made with light bulbs in their handles to which are attached Lucite tubes shaped so they can throw light into any corner of the mouth or throat. Also, doctors have had to remove wood or metal splints from broken limbs to see how far healing has progressed. With recently designed Lucite splints, however, it will be possible to keep a patient’s bones in a firm position and at the same time examine the fractured arm or leg without removing the support.
Rohm & Haas Co., Inc., in Philadelphia, make two transparent plastics of similar composition called Crystalite and Plexiglas, and among the possibilities of such materials are plastic lenses. When you go to an eye specialist for a pair of glasses, you may have to pay from $5 to more than $20. A large part of this expense goes to expert lens makers who have to grind glass carefully to remedy your particular ailment But prices may go tumbling down if plastics experts can make long-lasting lenses by high-speed molding methods.
One plastic is made with casein, a chemical found in milk. Another new German material may be used for printing type, since it has many of lead’s best qualities and is much lighter. But Dr. Baekeland’s company is more than keeping up with latest developments. It makes more than 15,000 different articles for 35 major industries, and recently a spokesman announced that the Bakelite Corporation, in cooperation with the United States Army and Navy, was preparing to make airplanes with the aid of plastics. This is to be done by “soaking” wood with plastics, and the process is expected to eliminate all riveting and make it possible to construct 20 to 30 planes in the time it takes to build one.
Meanwhile Dr. Baekeland, at 75, rarely misses a day’s work. He is firmly established as one of the greatest pioneers in the plastics industry.