During the mid-20th century, Freon was little appreciated but indispensable. The DuPont-produced gas made widespread use of refrigerators and air conditioners possible and served as a propellant in aerosol sprays of all types. Up to the 1920s, most commonly used refrigerants were exceedingly hazardous substances. Late in the decade, two scientists doing research for General Motors’ (GM) Frigidaire subsidiary developed an inert, nontoxic and odorless replacement chlorofluorocarbon gas (CFC) gas called Freon . GM asked DuPont to develop the product on a large scale and a plant was built at Deepwater, N.J., in 1930. In their work with the substance, DuPont scientists discovered that Freon also made an effective aerosol propellant. Related CFCs also proved effective as degreasing agents and as the basis for Teflon®, a remarkably durable and inert plastic. Freon products were produced and marketed through a joint DuPont-GM venture called Kinetic Chemicals Company up to 1949 when the operations came under control of the Organic Chemicals Department.
Demand for Freon refrigerants and propellants continued to grow until the 1970s when scientific studies indicated that CFCs were depleting the ozone layer that shielded the earth from harmful ultraviolet radiation. During the 1980s DuPont began developing more environmentally friendly hydrofluorocarbons (HFCs), eventually marketed as Suva refrigerants and Dymel propellants. During the 1980s, federal regulatory agencies banned the use of CFCs and DuPont began phasing out production, producing its last CFCs in the developed countries in 1995. The difficulties faced by American producers and consumers alike in curtailing their use of Freon were a testament to its profound impact on postwar life.
DuPont fluorochemicals can be found in products ranging from stadium roofs to kitchen frying pans. The first significant developments in fluorochemical research began at General Motors (GM) in the 1920s. GM, and its subsidiary Frigidaire, had been searching for nontoxic, nonflammable substitutes for existing refrigerants. Researchers discovered a promising alternative in dichlorodifluoromethane, later called Freon 12. Lacking the capacity to produce Freon in large quantities, GM turned over subsequent development to DuPont in a joint venture called Kinetic Chemicals Company. By the end of the 1930s, DuPont’s Freon sales were nearly $4 million a year. The company expanded the use of Freon to aerosols, cleaning liquids and foam-blowing agents.
Further fluorochemical research led to the discovery of polytetrafluoroethylene, which DuPont would later trademark Teflon. Tests on the new material showed that it was unaffected by most acids and corrosive chemicals and remained solid at temperatures much higher than any other plastic. During World War II, Teflon found its first significant use in nose cones on artillery-shell proximity fuses. Teflon was also used in the secret atomic research of the Manhattan Project because it could withstand the corrosive environment surrounding the production of Uranium-235. Although earliest uses of Teflon were in national defense, the fluorocarbon found its largest market in 1961 when it was introduced as a non-stick coating for cookware.
By the early 1970s, DuPont had developed a group of high-performance fluoroplastics like Tefzel fluoropolymer resins for wire insulation and Teflon PFA melt-processible plastic for chemical equipment linings and specialty tubing. Tedlar® polyvinyl fluoride brought longer life to aluminum home siding and a line of fluoroelastomers served important needs in the industrial sealant market.
Scientific research in the 1970s revealed a link between chlorofluorocarbons (CFCs) and the depletion of the earth's ozone layer. A leading manufacturer of CFCs, primarily Freon, DuPont made an early commitment to phase out CFC production and find safer fluorochemical alternatives. DuPont developed hydrofluorocarbons (HFCs) like Suva refrigerant, Formacel® foam expansion agents, and Dymel propellants for aerosols. Other fluorochemicals have been enlisted in environmental protection. For example, filtration fabrics made of Teflon fibers keep coal ash and other industrial pollutants out of the atmosphere. Today, DuPont continues to develop fluorochemicals that are environmentally responsible and serve a variety of industrial and consumer markets.