Giulio Natta

Italian chemist

• Born: February 26, 1903
• Birthplace: Imperia, Italy
• Died: May 2, 1979
• Place of death: Bergamo, Italy

Natta was awarded the Nobel Prize in Chemistry in 1963 for his work on macromolecular synthesis with total control of the relative spatial orientation of groups of atoms that are bonded to the polymer chain. This important development revolutionized the plastics industry and made possible the use of polymers in widespread applications, such as plasticware, laundry detergents, microwavable containers, and antiknock admixtures to high-octane fuels.

Early Life

Giulio Natta (ZHEW-lyoh NAHT-tah) was born on the Italian Riviera to Francesco Natta, a prominent attorney and judge, and Elena (Crespi) Natta. He was educated in the nearby city of Genoa. Natta claimed that his interest in chemistry began at the age of twelve, when he found that he could not put his chemistry book aside. “From then on, chemistry was my love,” he said. He was graduated with honors from Genoa’s high school of science in 1919, at the age of sixteen. Initially, he was enrolled in the pure mathematics course at the University of Genoa but found that mathematics was too abstract. As his father had taken up the challenge of putting the ideals of justice into practice, so also was Giulio attracted by the application of the concepts of chemical theory to the solution of practical questions, and this led him to transfer to the Polytechnic Institute of Milan, where he studied chemical engineering. He received his doctorate degree in chemical engineering from the Polytechnic Institute in 1924, five years after his high school graduation.

In his Nobel presentation on December 12, 1963, Natta stated that he first became interested in the spatial relationships of atoms and in structural chemistry in general while he was still a student and apprentice of a Professor Bruni in 1924. It was then that Natta learned the techniques of structure elucidation by X-ray analysis. This analytical procedure was complemented by his study of analysis by electron diffraction at Freiburg, Germany. While in Freiburg, Natta came to know Hermann Staudinger, who was pioneering the analysis of polymers by chemical methods, and he was so influenced by Staudinger that he resolved to investigate the structure of polymers using electron diffraction and X-ray techniques.

On April 25, 1935, Natta married Rosita Beati, a literature teacher at the University of Milan. They had two children, Franca and Giuseppe. He remained close to his wife throughout his life, and it was through her influence and background in literature that the word “isotactic” was coined to describe the structure of the particular form of polypropylene that he had prepared and that marked the beginning of his prizewinning research. Natta’s need to combine theory with practical applications was a basic driving force throughout his life. He utilized the techniques of X-ray analysis and electron diffraction, both of which he had learned at a very early stage in his career, throughout his research.

Life’s Work

After obtaining his doctorate in chemical engineering in 1924, Natta remained at the Polytechnic Institute of Milan as an instructor. His talents as an educator were quickly recognized and marked by his rapid rise through the academic ranks. In 1925, he was made assistant professor of analytical chemistry and was promoted to professor of general chemistry in 1927. During this period, Natta’s research centered on the application of X-ray analysis to the structure elucidation and crystallinity of inorganic substances. He used X-ray analysis to investigate the properties of industrial catalysts. In 1932, he visited the University of Freiburg in Germany to learn the new technique of electron diffraction and immediately began to utilize this new method in his work. His interaction with Staudinger inspired his idea to apply these analytical techniques to the investigation of macromolecular structure.

Natta returned to Milan in 1933 and then accepted a position as professor and director of the Institute of General Chemistry at the University of Pavia, where he remained for two years. He became professor of physical chemistry at the University of Rome in 1935, professor and director of the Institute of Industrial Chemistry at the Turin Polytechnic Institute in 1937, and then professor and director of the Industrial Chemistry Research Center at the University of Milan in 1938.

Because of his close ties to industrial applications of chemistry research, Natta was asked by the Italian government, under Benito Mussolini, to initiate research and development on the production of synthetic rubber , and he successfully implemented the industrial production of butadiene-styrene rubbers at Ferrara during World War II. His earlier work on industrial catalysts also led at this time to his development of catalytic processes for production of methanol and other alcohols, as well as formaldehyde and butyraldehyde. After the war, Montecatini, a large Italian chemical company in Milan, funded much of Natta’s research. The low cost and availability of petroleum stimulated his work in the use of petroleum as a raw material base for industrial chemicals and monomers used in plastics production.

Natta became immediately interested in the work of Karl Ziegler, who had succeeded in preparing high molecular weight polyethylene using transition metal compounds as catalysts, in 1952. Since Ziegler was working on ethylene polymerization, Natta turned his attention to propylene, which has one more carbon than ethylene. Propylene had the advantage of being much cheaper than ethylene, as it was a by-product of the petroleum and propane refining processes.

All Natta’s previous research knowledge and industrial experience came to bear on this effort. In 1954, Natta announced that he had succeeded in preparing a new polypropylene that was far superior in physical properties to that previous methods could produce. He used X-ray and electron diffraction techniques to show that his polymer had a greater degree of crystallinity than could be obtained previously. In fact, all the methyl groups, which are bonded to the backbone of the polymer chain, where shown to be oriented so that they were all on the same side of the chain. The new class of polymers, where the stereochemistry (the relative spatial arrangement of atoms and groups) could be controlled, was called stereoregular polymers. Further research with a variety of vinyl polymers and catalyst systems led to the total control of macromolecular stereochemistry during the polymerization process. Isotactic polymers, with pendant groups all on the same side of the chain, and syndiotactic polymers, with pendant groups alternating from side to side with each monomer unit, could now be prepared readily and inexpensively.

Natta became a member of the National Academy of Sciences of Italy in 1955. He visited the United States in 1956, and showed several articles made from isotactic polypropylene, including a cup, a washing-machine agitator, and pipes, at a press conference. Montecatini was producing the polymer on an industrial scale in 1957, and the patented process was licensed throughout the world.

He continued research in the area of polymer science and made many other notable contributions. These included the stereospecific polymerization of butadiene to give polybutadiene, which had a configuration analogous to natural rubber. The copolymerization of ethylene with other monomers gave unusual rubber materials in that no double bonds were present in the macromolecule. He also developed the asymmetric synthesis of polymers, where an optically active macromolecule can be produced from optically inactive monomers. To mimic biological processes in this way was a remarkable and insightful achievement. In the 1960’s, Natta was continuing this extensive work with the polymerization of nonhydrocarbon monomers, such as benzofuran, and vinyl ether.

Numerous gold medals were awarded to Natta in recognition of his scientific contributions, including the First International Gold Medal of the Synthetic Rubber Industry (1961), the Society of Plastics Engineers Gold Medal (1963), the Lavoisier Medal from the French Chemical Society (1963), and the Perkin Medal (1963). He also received honorary degrees from the University of Turin (1962) and from the University of Mainz (1963). Natta was awarded the Nobel Prize in Chemistry, jointly with Ziegler, in November, 1963. Arne Fredga of the Royal Swedish Academy of Sciences observed, during the formal presentation, that nature’s monopoly on stereospecific and asymmetric polymerization had been broken.

In the last twenty years of his life, Natta became increasingly limited in his activities by Parkinson’s disease. He could still go for long walks in the woods and hunt for mushrooms with his wife, but his other hobbies, mountain climbing and skiing, were impossible. Natta also had an interest in fossils and kept a collection of petrified fish. He continued his impact on chemistry education as coeditor of the book Stereoregular Polymers and Stereospecific Polymerizations (1967) and was coauthor of Stereochimica: Molecole in 3D (1968; Stereochemistry, 1972) with Mario Farina; he retired in 1972. Natta died in Bergamo, Italy, on May 2, 1979, following complications from surgery for a broken femur.

Significance

The driving force in Natta’s scientific achievements was the desire to apply the theories of chemistry to practical applications. His background in engineering and chemistry provided him with the intellectual tools required to transform ideas into reality. He was known as “the wizard of plastics” and was one of the foremost personalities in leading the world into the age of plastics. The explosive expansion of the plastics industry and the use of plastics in every facet of life brought about environmental stress as the result of the quantities of durable waste accumulating in dump sites. Legislation has been aimed at limiting the type and quantities of plastics waste. Many industrial projects in the plastics industry have been initiated to develop product biodegradability and the recyclability of polymers.

The impact of Natta’s contributions can hardly be overstated. Much of the plasticware used in household goods, scientific and medical laboratories, microwavable containers, detergents, pipes, and antiknock additives are a direct result of his work. He laid the foundations for understanding the relationships between polymer structure and the resulting physical properties of polymers. These discoveries influenced the development of the entire plastics industry. The advancement of technology in many other fields, such as the aerospace industry, computers, and the automotive industry, are directly related to the availability of inexpensive, lightweight materials that outperform metals, wood, and paper in terms of strength, durability, heat resistance, and other physical properties.

Bibliography

“Giulio Natta.” In Current Biography Yearbook 1964, edited by Charles Moritz. New York: H. W. Wilson, 1964. Contains much of the biographical material available on Natta. The article mentions some of his coworkers by name and lists the early trade names of some of the plastics produced industrially by Montecatini and others. References at the end of the article provide a few other sources.

Hargittai, István, Angiolini Comotti, and Magdolini Hargittai. “Giulio Natta.” Chemical and Engineering News 81, no. 6 (February 10, 2003): 36. A profile of Natta, featuring information on his family background, education, career, awards, and achievements.

McGraw-Hill Modern Scientists and Engineers. Vol. 2. New York: McGraw-Hill, 1980. The section on Natta summarizes his scientific achievements and lists a reference on Hermann Staudinger, who influenced Natta’s interest in high polymers, as well as references to the polymerization process in general, to rubber, and to stereochemistry.

Meikle, Jeffrey L. American Plastic: A Cultural History. New Brunswick, N.J.: Rutgers University Press, 1995. An interdisciplinary cultural history of the world of plastics, written by an art historian and professor of American studies. Explores plastics in the context of invention and technology, material culture studies, advertising and marketing, industrial design, consumerism, and cultural history. Recommended especially for those seeking a nontechnical study of the effects of Natta’s work beyond the sciences.

Natta, Giulio, and Ferdinando Danusso, eds. Stereoregular Polymers and Stereospecific Polymerization. London: Pergamon Press, 1967. This book is a compendium of Natta’s publications. Since most of Natta’s research was published in Italian, or languages other than English, the book is an invaluable source to anyone wishing access to Natta’s original work.

Natta, Giulio, and Mario Farina. Stereochemistry. Translated by Andrew Dempster. London: Longman, 1972. An excellent source on the technical aspects of stereochemistry for college-level students. Many parts can be read with a minimal background in chemistry. Shows the clarity of thought that Natta had in visualizing molecules in three dimensions and contains many illustrations. Discusses the entire field of stereochemistry and is not limited to the polymer aspects. Biological considerations are extensively treated.

Wasson, Tyler, ed. Nobel Prize Winners. New York: H. W. Wilson, 1987. The chapter on Natta gives the English translation of the formal presentation speech made by Arne Fredga of the Royal Swedish Academy of Sciences as well as Natta’s Nobel lecture. An extensive list of references are cited at the end of the lecture, and these are followed by a condensed biographical sketch, which details Natta’s awards and honors.