By Carin A. Helfer and Kristof Molnar
Polymers? Do you mean plastics? Many people do not know the term polymer, but this material is literally everywhere and a major part of our daily life. Plastics are polymers, but rubbers and fibers are polymers, too. Probably the most recognized biological polymer (biopolymer) is deoxyribonucleic acid (DNA). Carbohydrates, proteins, cellulose, silk, and cotton are biopolymers, also. Life would not be possible without biopolymers.
Some man-made (synthetic) polymers are silicone rubber, which can be used in caulk; polyethylene (PE), which is used to make milk jugs; nylon, which is used in clothing and parachutes; and polyethylene terephthalate (PET), which is used to make soda and water bottles. Even your white glue and other adhesives are polymers. If you look around, you will find many polymers throughout your day.
Large quantities of both synthetic and natural rubber, usually a combination for optimum performance, are used in tires. Interestingly, back in the early 1930s, steel-wheeled tractors were used in agriculture. Unfortunately, the operators ended their day sore from the pounding of the steel-wheeled tractors. Of all the tire companies in Akron, the Firestone Company was the first to be successful in creating a rubber tractor tire. However, the idea of rubber tractor tires did not catch on quickly. In 1932, when Professor G.W. McCuen of The Ohio State University presented research data on the new rubber tires that showed greater fuel efficiency, greater drawbar pull, higher operating speeds, and more operator comfort, the tractor companies were skeptical. In 1937, after a two-year campaign by the Firestone Company, only 42% of all new tractors in the U.S. were equipped with rubber tires. However, the number quickly grew in the next few years.
Natural rubber, which is used in tires, industrial products, and consumer products, starts as a milky substance tapped from trees grown in tropical climates. Currently, the natural rubber that is commercially used in the U.S. comes from the Hevea brasiliensis tree, which grows in Southeast Asia. A combination of exponentially growing demand in the upcoming years and potential loss of Hevea brasiliensis trees due to disease could limit imports of natural rubber needed in the U.S. Currently, researchers at OSU are working on two alternative natural rubber sources (i) Parthenium argentatum (guayule natural rubber), which is native to southwestern U.S.; and (ii) Taraxacum-kok-saghyz, which is a unique dandelion that produces rubber in its roots, and can be grown in the U.S. and even Ohio. Our lab is working on a new synthetic rubber that may lead to more fuel-efficient passenger and truck tires because of the polymer’s unique ring structure, instead of the standard linear structure.
Polymers are more than plastics and are literally everywhere. They changed our lives when they became widely available in a synthetic form, as much as our lives would change if they were to become obsolete. Because if you are honest with yourself, they are so infused in our lives that it would be unimaginable to live without them.
Dr. Carin A. Helfer is a Research Assistant Professor and Dr. Kristof Molnar is a Research Associate in the Department of Food, Agricultural and Biological Engineering of The Ohio State University. E-mail: firstname.lastname@example.org; email@example.com. This column is provided by the OSU Department of Food, Agricultural and Biological Engineering, OSU Extension, the Sustainability Institute and the College of Food, Agricultural and Environmental Sciences.