Hermann Staudinger was one of the most influential organic chemists of the twentieth century. His wide-ranging research interests included the investigation of many kinds of molecules, ranging from small organic compounds to large polymers. He is generally considered to be the father of macromolecular (polymer) chemistry and won the 1953 Nobel Prize in chemistry for his discoveries in that field.
Staudinger was born in Worms, Germany, on March 23, 1881. He at first planned to study botany at the University of Halle, but he subsequently followed his father's advice and switched to chemistry. After graduating from
Halle with a degree in chemistry in 1903, Staudinger moved to the University of Strasbourg and became an academic lecturer there in 1907. Subsequent academic appointments took him to Karlsruhe, Zurich, and, finally, Freiburg.
Although Staudinger's work on ketenes, diazo compounds, oxalyl chloride, and pentavalent phosphorus compounds is still relevant, he is more recognized for his seminal contributions to macromolecular chemistry. Staudinger started working on macromolecules in the early 1920s. Following his move to Freiburg in 1926, he discontinued his investigations of small organic compounds and concentrated exclusively on the chemistry of what he believed were high molecular weight compounds.
It was a risky career move for Staudinger, and one that put him at odds with many of the leading organic chemists of the time. He proposed (without much proof to back up his proposal) that macromolecules were long-chain molecules of identical or nearly identical units that were linked by covalent bonds . Today it is known that many of Staudinger's ideas were essentially correct, but in the 1920s most chemists disagreed with him. They viewed macromolecules as colloidal aggregates of small molecules and did not believe that covalent bonding was involved.
Staudinger's colleague, Dr. Heinrich Wieland, told him to drop his idea of large molecule organic compounds and assured him that a sample of purified rubber would be shown eventually to be composed of low molecular weight compounds. During a lecture in Zurich in 1925, Staudinger was verbally attacked for advocating the idea of covalent bonding in macromolecules.
Despite the attacks, Staudinger was determined to convince his detractors that his ideas on the structures of macromolecules were sound. To prove his point he carried out a series of experiments designed to yield more understanding of the chemical and physical properties of polymers. He began with natural rubber. He and J. Fritschi hydrogenated the double bonds present in natural rubber polymer molecules in an autoclave and found that the isolated product had properties similar to those of the starting rubber. From this Staudinger concluded that natural rubber was not a colloidal substance, but a long-chain macromolecular substance.
He gathered more evidence by synthesizing polymers from formaldehyde and from styrene. The homologous formaldehyde-derived polymers spanned the molecular size range, from small molecules to large macro-molecules. From the results Staudinger concluded that polymers were molecules whose repeating units were linked by covalent bonds, and that they had characteristic functional groups at their ends. The polystyrene polymers were prepared under varying reaction conditions and had a range of molecular weights and physical properties. These data were also consistent with covalent bonding, but not with colloidal association.
Staudinger's ideas were gaining popularity, but it was a 1928 paper by Herman Mark and Kurt Meyer that finally convinced chemists that Staudinger had been right. Mark and Meyer used x-ray crystallography to probe the structure of a crystallized polymer and found that polymers were indeed long-chain molecules in which repeating units were linked by covalent bonds.
Staudinger spent the next twenty or so years building up macromolecular chemistry and helping to lay the foundation for today's multibillion-dollar polymer industry. He retired in 1951 and received the 1953 Nobel Prize in chemistry for his work on polymers. He died on September 8, 1965.
James, Laylin K., ed. (1993). Nobel Laureates in Chemistry 1901–1992. Washington, DC: American Chemical Society; Chemical Heritage Foundation.
"Science Explains Polymers." National Academy of Sciences. Available from http://www.beyonddiscovery.org .