Discovery of Plastic Polymer
26 SEP 2017
Hard, moldable plastics were in use for decades to manufacture hair combs and billiard balls before a German scientist discovered that they were organic polymers -- large, carbon-based molecules composed in chains of like units (called monomers). That was in 1922, and that discovery lit a fire under the plastics industry. Suddenly these quaint materials were used in mass production and for everything from toothbrushes and bristles to car and airplane parts.
1 Parkesine and Xylonite
In the 1850s, English inventor Alexander Parkes had been using cellulose to waterproof fabrics, according to SPI, the Plastics Industry Trade Association. Then in1865 at the Great Exhibition in London, introduced a hard plastic called Parkesine, also a cellulose material. The material could be shaped by dies or with pressure into combs, buttons and so forth. Parkes’ manufacturing company failed, as did the Xylonite Company in 1874, formed by an associate of Parkes.
2 Cellulose Nitrate (Celluloid)
Simultaneously with the development of Parkesine, American John Wesley Hyatt experimented with cellulose nitrate to produce plastic billiard balls versus ivory. In 1872 Hyatt and his brother Isaiah patented the first plastics injection molding machine, and they coined the term “celluloid” in 1874. Celluloid would later be used to produce such items as motion picture film, in a process patented by George Eastman Kodak. The 1880s fashion for long hair among women created a demand for celluloid combs versus natural horn.
A patent for "plastic compositions" that would later be Casein was taken out in Germany in 1899, according to the Plastics Historical Society. The patent would be used by the German manufacturer Vereinigten Gummivarenfabriken and the French company Compagnie Francaise de la Galalithe to produce a product named "Galalith." The companies merged in 1904 to form the International Galalith Gesellschaft Hoff and Company, and jointly developed a process that used dried casein granules as a raw material and produced a more stable plastic product, according to the Plastics Historical Society.
Casein was derived from a protein of cow’s milk, it took dye readily, and so could be used to produce colorful pens, combs, tableware and buttons, among other items. Casein would not become widely available for years, but in 1915 Queen Mary of England was charmed enough to order jewelry made from it.
4 The Discovery of Polymers
All of these inventors and manufacturers knew how their plastics worked, but not why. German scientist Hermann Staudinger solved the mystery in 1922, when he developed the concept of macromolecules, including polymers. Staudinger synthesized several polymers and proved that they were long chain molecules (comprised of identical monomers, like links in a chain). Twenty-one years later in 1953, Staudinger received the Nobel Prize for Chemistry for his discoveries.
While Staudinger waited, polymer science and manufacturing took off when such materials as Bakelite, nylon, Perspex and Formica were introduced, and manufacturers developed modern extruding and molding machines. Most of these materials (nylon included) were completely synthetic and petroleum-based, without the biodegradable properties of cellulose (and thus celluloid).