FLORA Sex( Chemist, Nobel Prize in Chemistry in 1974.)
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Biography FLORA Sex
FLORA, Paul (Flory, Paul) (1910-1985) (USA). Nobel Prize in Chemistry 1974. Born in Stirling, a town in Illinois, the son of Ezra the priest and teacher Martha Florey Florey. After completion of secondary education in 1927 went to Manchester College (Indiana). One of the professors, KV Hall, encouraged his interest in chemistry.
Having become in 1931 the bachelor, Flory continue to improve at Ohio State University, where he became a master of organic chemistry, then switched to physical chemistry - his thesis was on the photochemistry of nitrogen oxides.
After receiving his doctorate in 1934 at the same university Flory goes into the firm 'Dupont de Nemours' in Wilmington (Delaware), which entered the group of researchers led by W. H. Carothers. In 1937, Carothers committed suicide (it was the Great Depression), and next year Florey left a company and became an associate professor of basic science research laboratory at the University of Cincinnati (Ohio).
In September 1940 he became a senior chemist in the company 'Esso leboratris' in Linden (New Jersey), created under 'Standard Oil Development Company' (now 'Exxon Research for End enzhiniring Company'). To improve a new type of rubber - butyl obtained from the gas after the refining of oil - he studied the problem of elasticity of rubber.
When a firm 'Goodyear Tire Rubber End' invited him to lead a group of basic research, Flory took advantage of this opportunity and in October 1943 he moved to Akron (Ohio). Jobs 'Goodyear' created Flory fame, and it is not surprising that in the spring of 1948 he was invited by P. Debye (Nobel Prize in Chemistry, 1936), dean of the chemistry department at Cornell University, Ithaca (New York) to give lectures. His lectures laid the foundation for a new academic discipline - chemistry of polymers and allowed him to become a professor of chemistry at Cornell University.
Over 40 years Florey was researching the physical and chemical properties of polymers. Flory said: 'The acquisition of knowledge about this subject (macromolecule) must be regarded as necessary for understanding the relationship between chemical structure and the properties, . which makes the polymer active in living organisms and the necessary people ', .
Florey studied the kinetics of the reactions of polycondensation. In 1936, proved that there was no significant difference between the reactivity of the same chemical groups, located in the small molecules and polymers (Flory principle). In 1941-1952 he studied the kinetics of the three-dimensional polycondensation and molecular mass distribution of polymers formed in this.
Florey studied the mechanical properties of polymers. He developed a theory, which explained the regularity of formation of branches in some polymers, leading to the emergence of network structure, characteristic of elastic polymers. He proved that the number of defects in the mesh structure determines the strength of the polymer in the gap.
Florey found that in the solution configuration of polymer molecules with their large size can not be accurately described by a probabilistic-statistical method - an approach suitable for small molecules. The situation changes completely when the solution temperature is lowered to a certain value, which varies depending on the type of polymer. At such temperatures the solution becomes the 'ideal' solution (similar to the proposed R. Boyle 'ideal' gas - a concept introduced to study the properties of gases). The temperature at which the solution is ideal, is called the theta-point Flory.
Flory also discovered the possibility of defining some constants characterizing the properties of the polymer solution. In 1930, Staudinger showed that there is a linear relationship between the viscosity of the polymer solution and the average molecular weight of the polymer. Taking this direction, Florey in 1949 showed that the increase in the viscosity of the polymer solution is proportional to the radius of the molecule in the third degree. This constant is common to all solutions of polymers. On the basis of Flory was able to use a large amount of existing data to study the configuration of polymer chains, in particular, the natural macromolecular protein.
In 1956, Florey became deputy director for science in Mellonskom Applied Research Institute in Pittsburgh (Pennsylvania). There he took up the fundamental problems. Liquid crystals are widely used today in calculators and watches, were known only to specialists, when Florey in 1956 published his first work on the theory of liquid crystals.
Administrative activities burdened Flory, and in 1961 he was appointed professor at Stanford University in California.
His book, 'Statistical Mechanics of Chain Molecules ", published in 1969, summarizes research on physical and chemical properties of polymer molecules.
In 1974, Florey received the Nobel Prize "for fundamental contributions to both theoretical and experimental research in the field of physical chemistry of macromolecules'. In his Nobel lecture, he noted that one of the components of explosives used by Alfred Nobel - nitrokletchatka - is also a polymer
. Flora, by definition, the configuration of polymers developed together with the works of Professor MV Volkenshtein and a Japanese scientist Kazuo Nagai, . that led to the development of the statistical theory of physical-chemical properties of macromolecules and mathematical models of some biological processes, . Now the theory and methods in this area allow for real quantitative correlation properties of chain molecules with their chemical composition and structure. They have already found application in a wide range of diverse macromolecules, including such important natural compounds as polypeptides and polynucleotides
. Flory of the importance of his work said: 'The acquisition of knowledge about this subject (macromolecule) must be regarded as necessary for understanding the relationship between chemical structure and the properties, . which makes the polymer active in living organisms and the necessary people ', .
Following the resignation of Stanford University in 1975, Florey remained an active researcher. Since 1968 - Consultant 'International Business meshins' (IBM), and from 1977 spent a couple days a week in the department of polymer science and technology of this firm in San Jose (California).
The new technique of neutron scattering has given evidence in terms of Flory, the configuration of polymers in the amorphous state of disordered. In collaboration with researchers from the San Jose Flory developed this new field of polymer science, . continued to work with solutions of polymers and liquid crystals, and expanded the scope of research, . include the problem of elasticity (the study of fibrous proteins of muscle), .
Was fond of gardening, walking and cycling.
Died Sept. 8, 1985 of a heart attack while working at his country house in the Big Su, California.
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