Living Better Through Chemistry and Plastics

In the early 1930s, DuPont’s attempts to synthesize commercially viable polyester fibers were stymied by the problems of low melting points and high solubility in water. The research team, led by chemist Walter H. Carothers, turned its attention to polyamides rather than polyesters, and in 1934 pulled a polymer fiber based on an aminoethylester — the first nylon. The team would face two possibilities: polyamide 5,10, made from pentamethylene diamine and sebacic acid; and polyamide 6,6, made from hexamethylenediamine and adipic acid. (DuPont named its molecules for the number of carbons in the starting materials.) DuPont settled on polyamide 6,6, (“Fiber 66”) because the intermediates could be more easily prepared from benzene, a readily available starting material derived from coal tar. Read the Chemical Heritage Foundation's Science of Plastics.

Milestones

1910
Bakelite, the first entirely synthetic thermosetting plastic, is produced from phenol, formaldehyde and wood flour.

Leo Baekeland was searching for a synthetic replacement for shellac when he began experimenting with the reactions of phenol and formaldehyde. By controlling the pressure and temperature applied to an intermediate made from the two reagents, he produced a polymer that, when mixed with fillers, produced a hard moldable plastic. Bakelite, though relatively expensive, soon found many applications — from household products like the telephone to automobile components to the rapidly growing radio industry. (Bakelite)

1928
Polymethyl methacrylate (PMMA) acrylic glass in developed; marketed in 1933 as Plexiglas. (Rohm & Haas)

1937
Polystyrene is produced commercially. It was first made accidentally from a Turkish Sweetgum (Liquidambar orientalis) tree in 1839. (Dow Chemical)

1939
Polyamide Nylon 66 is produced commercially for use in women’s hosiery. (E. I. DuPont)

1941
Polyethylene terephthalate (PET), the first polyester, and Terylene (a trademark of ICI, known as Dacron in the U.S.), the first polyester fiber, are developed. (E. I. DuPont)

1942
Foamed polystyrene (Styrofoam) is produced and first used to float U.S. Coast Guard six-man life rafts. (U.S. Coast Guard; Dow Chemical)

1946
Teflon is marketed under its trademark. It was first inadvertently produced in 1938 from compressed/frozen tetrafluoroethylene. (E. I. DuPont)

1952
Mylar polyester film is introduced; used widely in electrical, electronics, imaging, and graphics applications. Commercialized in 1952, Mylar replaced cellophane as the major product of the DuPont Film Dept. (E. I. DuPont)

1953
First-generation alkyl metal catalysts (TiCl3 and AlEt2Cl) are developed for polymer­izing alpha olefins (e.g., ethylene and propylene). Important products include linear low-density polyethylene and crystalline polypropylene. (Ziegler-Natta)

1955–1959
High-density polyethylene (1955–1956), polypropylene (1957–1958) and stereo-specific rubber (1958–1959) are commercialized. (Hoechst; Grace; Hercules; Phillips)

1959
First commercial production of thermoplastic polycarbonates — products characterized by outstanding low-temperature ductility, impact resistance and superior optical clarity (Lexan trademark). (General Electric)

1977
Fluid-bed catalytic process is commercialized to produce polyethylene copolymerized with three to six carbon alpha olefins (propylene, n-butane, etc.). This development allowed precise control of polymer properties (UNIPOL trademark). (Union Carbide)

1982
Structural composites (e.g., 1984 Corvette bumper) are manufactured using reaction injection molding, the rapid mixing/reaction of isocyanates and polyols. (NSF; Bayer; Dow; Texaco)

1993
Metallocene catalyst is developed to produce ethylene copolymers of exceptional strength, toughness and film clarity. Metallocenes are made of metal atoms held between two carbon rings. (Dow Chemical)

2003
Fermented corn sugar is converted to short-chain polylactic acids for use in plastics and fiber manufacture. (Cargill; Dow LLC)