Scientists » Chemists » PAUL FLORY
|Full name||: Paul Flory|
|Alias||: Paul Flory|
|Address||: Sterling, Illinois, U.S|
|Animals||: The Dog|
|Father||: Ezra Flory|
|Mother||: Martha Brumbaugh Flory|
|Wife||: Emily Catherine Tabor|
|Children||: Susan Flory Springer, Melinda Flory Groom, John Flory, Jr|
|Education||: Manchester University (Indiana) Ohio State University|
Paul Flory was an American chemist considered as the founder of the science of polymers. He was most reputed for his pioneering contributions in the field of polymers or macromolecules. His leading-edge scientific work in comprehending the behaviour of polymers in solution won him the prestigious ‘Nobel Prize in Chemistry’ in 1974 "for his fundamental achievements, both theoretical and experimental, in the physical chemistry of macromolecules". He examined properties of polymers and made significant contributions in comprehending solution thermodynamics, hydrodynamics, molar mass distribution, glass formation, crystallization, melt viscosity, elasticity and chain conformation. He found that growth of an increasing polymeric chain can stop if it reacts with other molecules that are present and in that case it initiates a new chain. The theory of polymer networks was developed by him to elucidate the method of gelation. Later he also developed a theory of anistropic solutions and a theory of rubber networks. Post retirement he worked in Eastern Europe and Soviet Union as a human rights advocate. He served in academic institutions as well as in industrial sector and he was immensely interested both in the theory of macromolecule as also in its practical uses. He received many awards apart from ‘Nobel Prize’ which included ‘Charles Goodyear Medal’ (1968), ‘Priestley Medal’ (1974) and the ‘National Medal of Science’ (1974).
After completing his PhD, Flory joined ‘Central Research Department’ of ‘E.I. du Pont de Nemours and Company’ in 1934. There he worked as a research chemist in a small team under Wallace Hume Carothers, an American chemist who invented nylon and neoprene. His curiosity regarding basics of polymerization and polymeric substances were aroused here following his association with Dr. Carothers.
Flory was designated to examine physical chemistry of polymers. He worked in the field of polymerization kinetics that is studying reaction rates of chemical processes in polymerization.
Regarding condensation polymerization, a type of step-growth polymerization, he disputed with the postulation that with growth of macromolecule, the reactivity of the end group deceases. He argued that reactivity of end group was independent of size of macromolecule and deduced that the number of chains present decrease exponentially with size.
Flory introduced the significant perception of ‘chain transfer’ (a polymerization reaction that results in transfer of the activity of a growing polymer chain to another molecule) in addition to polymerization for improvement of the kinetic equations and for better comprehension of polymer size distribution.
Following Dr. Carothers’s death in 1937, Flory started working at the ‘Basic Science Research Laboratory’ at the ‘University of Cincinnati’ from 1938. While serving there for two years he developed the theory of polymer networks to elucidate the method of gelation. During that tenure he also developed a mathematical theory for polymerization of those compounds that consist of more than two functional groups.
When the ‘Second World War’ broke, he began working in the industrial sector. From 1940 he started serving the laboratory of ‘Standard Oil Development Company’, in its Linden, NJ location. It is here that he initiated development of a statistical mechanical theory for polymer mixtures.
At that time research and development of rubber took prominence. In 1943 he joined Research Laboratory of ‘Goodyear Tire and Rubber Company’, and worked there as Director of Research till 1948, leading a team on polymer fundamentals.
He held the ‘George Fisher Baker Non-Resident Lectureship in Chemistry’ at the ‘Cornell University’ in the spring of 1948 after accepting invitation of Professor Peter J.W. Debye, the then Chairman of that Department. This stimulating experience and a subsequent offer of a professorship led him join the university in the fall of that year, and he served the post till 1957.
One of the most effective and fulfilling phases of his research career followed at the ‘Cornell University’. In 1949 he was initiated into the Tau Chapter of ‘Alpha Chi Sigma’ at the university.
In 1953 his chef d'oeuvre ‘Principles of Polymer Chemistry’, an elaborated and refined version of his Baker Lectures was published by ‘Cornell University Press’, which soon established itself as a standard text in the field of polymers and is used broadly till present.
He applied the concept of ‘excluded volume’ to polymers molecules, which was introduced by Swiss physical chemist Werner Kuhn in 1934. The concept elucidates that it is not possible for one of the parts of a long chain molecule to occupy a space which is already taken up by the molecule’s another part.
One of his significant accomplishments was the ‘Flory-Huggins Solution Theory’ an original procedure to calculate apparent size of a polymer in good solution. He also deduced the ‘Flory exponent’ that aids in distinguishing polymer movements in solution.
In 1957 he became Director of Research at the ‘Mellon Institute’, ‘Carnegie Mellon University’ and retained the position till 1961.
From 1961 to 1966 he served as Professor of Chemistry at the ‘Stanford University’ following which he became Jackson-Wood Professor of Chemistry at the university and served the position till his retirement in 1975.
He led an active life post retirement that saw him consulting ‘DuPont’ and ‘IBM’ for quite a while. He fought for the scientists who were oppressed, particularly in the Soviet Union and remained an advocate of the ‘Committee of Concerned Scientists’ and ‘Scientists for Sakharov, Orlov, and Shcharansky’ (SOS). In this pursuit he often spoke on the ‘Voice of America’ broadcast to the Eastern Europe and Soviet Union.
From 1979 to 1984 he worked for the ‘Committee on Human Rights’ of the ‘National Academy of Sciences’ and also remained a delegate at the Scientific Forum held in Hamburg in 1980.
More than 300 scientific writings were published by him. Two of his other notable books include ‘Statistical Mechanics of Chain Molecules’ published in January 1969 and ‘Selected Works of Paul J. Flory’ published in 1985.
He was born on June 19, 1910, in Sterling, Illinois. His father, Exra Flory was a clergyman-educator while his mother, Martha Brumbaugh Flory was a school teacher. He had two step-sisters, Margaret and Miriam, and one younger brother James.
He studied at ‘Elgin High School’ in Elgin, Illinois from where he completed his graduation in 1927.
Thereafter he enrolled at ‘Manchester College’ (presently ‘Manchester University’), a Brethren liberal arts college in North Manchester, from where he earned a BS in Chemistry in 1931. It is here that his interest in science, especially chemistry was infused by an exceptional professor, Carl W. Holl.
Encouraged by professor Holl, he applied and got enrolled at the Graduate School of ‘Ohio State University’ located at Columbus, Ohio. The chemistry department of the school was among the largest in the US. Here he developed immense interest in physical chemistry.
In 1934 he earned a PhD in Physical Chemistry from ‘Ohio State University’ submitting thesis on photochemistry of nitric oxide, which he carried out under supervision of Professor Herrick L. Johnston.
In 1936 he married Emily Catherine Tabor and the couple was blessed with three children two daughters, Susan Flory Springer and Melinda Flory Groom and son John Flory, Jr. All his children pursued science and his son went on to become a geneticist.
On September 9, 1985, he succumbed to heart attack in his weekend home in Big Sur, California, at the age of 75.
The Flory convention is named after him.
In 2002 he was inducted into the prestigious ‘Hall of Fame’ of ‘Alpha Chi Sigma’ posthumously.