Elmer Keiser Bolton
Encyclopedia
Elmer Keiser Bolton was an American chemist and research director for DuPont
, notable for his role in developing neoprene
and directing the research that led to the discovery of nylon
.
in Lewisburg
, Pennsylvania
and took the Classical Course, receiving a B.A. Degree in 1908. From there he went to Harvard University
, receiving his A.M. degree in 1910 and his Ph.D. in organic chemistry in 1913. His thesis advisor was Charles Loring Jackson
and his dissertation concerned the chemistry of periodoquinones.
Several other prominent contemporaries of Bolton's at Harvard Graduate School
were Roger Adams
, Farrington Daniels
, Frank C. Whitmore
, James B. Sumner
and James Bryant Conant
. Adams was particularly influential through Bolton's career. They shared diverse interests, yet a drive for accomplishment in organic chemistry. In later years Adams had significant influence on Bolton's ideas about industrial support of chemical research and university students.
In 1913 Bolton won the Sheldon Fellowship, which he used to work at the Kaiser Wilhelm Institut outside of Berlin, Germany for two years with Professor Richard Willstätter
. Here he worked on anthocyanins, a major program for Willstätter, and published three papers on isolation and structures of anthocyanin
pigments. Willstätter, apparently impressed by Bolton's ability but frustrated by his tendency to make arithmetic mistakes, commented "You must have been a bank teller." To his surprise Bolton replied that he had been a bank teller, this was how he paid his way through college.
Bolton was very impressed by Willstätter's careful, logical approach to tackling a research problem. He felt that this was the result of good training in the German university system. He also observed the relationship between German universities and industry, for which there was no counterpart in the United States. Another aspect of German research that impressed Bolton was the effort to create artificial rubber. This work was significant to German industry, and later to the German war effort in World War II
because Germany did not have ready access to sources of natural rubber. Also, the approach being used by the Germans undoubtedly lead to the development of neoprene rubber years later at DuPont Labs.
Bolton married Margarite L. Duncan in 1916 and they had three children, a daughter and two sons. He retired from DuPont after a distinguished career in 1951, but continued to follow the scientific literature. He died July 30, 1968 at the age of eighty-two.
(1914) most organic compounds had been imported from Europe
, but disruptions caused by the War presented an opportunity for American chemical companies to become established in this area, and to meet a wartime need. When Bolton returned from Germany in 1915 he discovered American organic chemists struggling to develop methods for manufacturing these compounds. The Dupont Company needed chemists, and hired Bolton in 1915.
Bolton joined the Chemical Department at the Experimental Station outside Wilmington
, Delaware
, where most of DuPont's research was conducted. Being groomed for advancement, he started working on the synthesis of glycerol. By 1916 Bolton was selected to lead the Dye
Group that was newly formed to research the synthesis of dyes. The United States had little knowledge of dye manufacture at this time, so later in 1916 Bolton traveled to England to learn about British technology in this area, and upon return he was assigned to the Wilmington Office to be advisor on dyes and intermediates. In 1918 he transferred to the Dyestuffs Department and was assistant general manager of the Lodi Works where silk colorants were made. In 1919 he returned to the Chemical Department as manager of the Organic Division. During this time he learned much about developing manufacturing processes and developed two principles; that high priority must be given to cost and time effectiveness of research, and that a manufacturing process should be perfected using pure materials, then later adapted to use materials available to the plant. Bolton's friend from Harvard, Roger Adams shared much of Bolton's philosophy in his work at the University of Illinois at Urbana-Champaign
.
In 1922 DuPont reorganized its research by dividing the entire research enterprise into four parts, each assigned to one of its four production areas. Bolton was made director of research for the Dyestuffs Department where his ability in this capacity was quickly realized. Dye manufacture requires the synthesis of a large number of intermediate compounds, and Bolton realized these could be used in many activities outside the Dyestuffs Department. By 1923 his lab was working on accelerators for manufacture of synthetic rubber
and soon after extended the research to include antioxidants for gasoline and rubber, floatation agents, insecticides, seed disinfectants, and large scale manufacture of tetra-ethyl lead
.
were also taking an interest in the problem.
Work on synthetic rubber began with the polymerization
of butadiene obtained from the hydrogenation
of diacetylene
, and at first not much progress was made. At the end of 1925 Bolton met chemist Julius Arthur Nieuwland from the University of Notre Dame
who had discovered a way to polymerize acetylene
using a cuprous oxide catalyst. Unfortunately the resulting polymer would explode when struck, but Bolton believed the process could be modified to produce a stable compound that would replace butadiene in the reaction. Bolton brought Nieuwland into the project as a consultant to DuPont, and Nieuwland taught the DuPont chemists how to use his catalyst. A continuous-flow reactor was developed that would produce a good yield of the stable polymer Bolton was seeking. While the polymer was highly chemical resistant, it degraded with exposure to light.
In 1927 DuPont's Chemical Director C.M.A. Stine persuaded the company to take on a fundamental research project for synthetic rubber and received $250,000 in funding for this purpose. In 1928 Wallace Carothers
, an instructor at Harvard University, was hired to lead the newly formed group. Bolton operated within this group and by 1929 had discovered that his polymer could be readily converted into 2-chlorobutadiene (chloroprene
) with a copper catalyzed addition of hydrogen chloride
. This material was both chemical and light resistant, with the properties of a synthetic rubber.
The new material was announced at the Rubber Division of the American Chemical Society
on November 2, 1931, and was called Duprene (today it is called neoprene
). By this time the Stevenson Act had been repealed and the Great Depression
had begun. Rubber prices were low and the new material cost twenty times what natural rubber cost. Therefore it never became a substitute for natural rubber, but it did find commercial use in applications where a rubber compound was needed that was more resistant to oils and outdoor degradation. Applications of neoprene include: the Rigid-hulled inflatable boat
; diving suit
s, and diveskins; glove
s, balaclavas, sleepsacks, Knee high boots, wetsocks and other protective clothing; radar absorbent material
; plumbing fixture
s; gaskets, hose
s, seal
s and belt
s; foam
(mousepad
, wetsuit
); orthopedic braces; and solid fuel rocket propellant (see AGM-114 Hellfire
).
and celluloid
were known and some synthetic polymers such as bakelite were also known and relatively common. The General Bakelite Company company was producing about 200,000 tons of Bakelite annually. Unfortunately the existing polymers could not be drawn into fibers and spun into thread, so the opportunity was to manufacture thread
from synthetic polymers to replace natural fibers such as cotton
.
The approach taken by Carothers' group was to adapt known synthesises that produced short chain polymers to produce long chain molecules. The first break was finding that bifunctional esterification could produce long molecule chains which today are known as aliphatic polyester
s, but at that time were called superpolymers. Then there was the key observation by Julian W. Hill in April, 1930 in which it was seen that the superpolymers could be drawn in the molten state to form thin, transparent fibers that were much stronger that the polymers were in the undrawn state. However, the superpolymers the group was able to synthesize either had too low a boiling point and insufficient chemical resistivity or had too high a melting point to be spun. By late 1932 the entire project was discontinued.
Bolton, now the Chemistry department director, refused to give up. Most likely he was aware of the re-discovery of polyethylene
by Eric Fawcett
and Reginald Gibson at Imperial Chemical Industries
in 1933. In early 1934 Bolton urged Carothers to continue the research, and Carothers decided to take another look at polyamides.
Carothers surmised that the problem with the polyamides that had been made from ε-aminocaproic acid
was due to cyclization reactions, so he replaced ε-aminocaproic acid
with 9-aminononoic acid which would not cyclize. This produced results that were encouraging, so Carother's group prepared polyamides from a variety of compounds including amino acids, dibase acids and diamine
s. The leading candidate for development became 5/10 polyamide made from pentamethylenediamine and sebic acid. It had the right melting point, the desired properties in fiber form and could be spun
without gel
formation.
Bolton at this point made a bold and characteristically visionary decision. He decided that practical synthetic fibers could not be made from castor oil
, the only practical source of sebacic acid
. To use an agricultural product as a primary feedstock would mean the new synthetic material would have very similar mass production problems as existing natural fibers had. Instead he wanted to use benzene
as the feedstock for making both adipic acid
and hexamethylenediamine
to make a 6/6 polyamide.
This polymer was first made early in 1935, and thanks to concurrent development of polyamine spinning technologies, could be spun into fibers. The fibers had high strength and elasticity, were insensitive to common solvents and melted at 263 °C, well above ironing temperatures.
Bolton insisted that every aspect of the synthesis of this polymer be thoroughly worked out in a pilot plant at the Experimental Station. He insisted that the development begin with pure materials then be adapted to use materials available to a plant in bulk.
On October 27, 1938 DuPont announced it would build a plant at Seaford, Delaware
to make nylon
, the world's first fully synthetic fiber. The Seaford plant was essentially a scaled up version of the pilot plant, and had remarkably trouble-free startup.
:
DuPont
E. I. du Pont de Nemours and Company , commonly referred to as DuPont, is an American chemical company that was founded in July 1802 as a gunpowder mill by Eleuthère Irénée du Pont. DuPont was the world's third largest chemical company based on market capitalization and ninth based on revenue in 2009...
, notable for his role in developing neoprene
Neoprene
Neoprene or polychloroprene is a family of synthetic rubbers that are produced by polymerization of chloroprene. Neoprene in general has good chemical stability, and maintains flexibility over a wide temperature range...
and directing the research that led to the discovery of nylon
Nylon
Nylon is a generic designation for a family of synthetic polymers known generically as polyamides, first produced on February 28, 1935, by Wallace Carothers at DuPont's research facility at the DuPont Experimental Station...
.
Personal life
Bolton was born in Frankford, Pennsylvania the oldest of two brothers. His father ran the furniture store on Main Street and both he and his brother attended public school in Frankford and went on to college. Bolton went to Bucknell UniversityBucknell University
Bucknell University is a private liberal arts university located alongside the West Branch Susquehanna River in the rolling countryside of Central Pennsylvania in the town of Lewisburg, 30 miles southeast of Williamsport and 60 miles north of Harrisburg. The university consists of the College of...
in Lewisburg
Lewisburg, Pennsylvania
Lewisburg is a borough in Union County, Pennsylvania, United States, south by southeast of Williamsport and north of Harrisburg. In the past, it was the commercial center for a fertile grain and general farming region. The population was 5,620 at the 2000 census. It is the county seat of Union...
, Pennsylvania
Pennsylvania
The Commonwealth of Pennsylvania is a U.S. state that is located in the Northeastern and Mid-Atlantic regions of the United States. The state borders Delaware and Maryland to the south, West Virginia to the southwest, Ohio to the west, New York and Ontario, Canada, to the north, and New Jersey to...
and took the Classical Course, receiving a B.A. Degree in 1908. From there he went to Harvard University
Harvard University
Harvard University is a private Ivy League university located in Cambridge, Massachusetts, United States, established in 1636 by the Massachusetts legislature. Harvard is the oldest institution of higher learning in the United States and the first corporation chartered in the country...
, receiving his A.M. degree in 1910 and his Ph.D. in organic chemistry in 1913. His thesis advisor was Charles Loring Jackson
Charles Loring Jackson
Charles Loring Jackson was the first significant organic chemist in the United States. He brought organic chemistry to the United States from Germany and educated a generation of American organic chemists.-Personal life:...
and his dissertation concerned the chemistry of periodoquinones.
Several other prominent contemporaries of Bolton's at Harvard Graduate School
Harvard Graduate School of Arts and Sciences
The Graduate School of Arts and Sciences is the academic unit responsible for many post-baccalaureate degree programs offered through the Faculty of Arts and Sciences at Harvard University...
were Roger Adams
Roger Adams
Roger Adams was an American organic chemist. He is best-known for the eponymous Adams' catalyst, and his work did much to determine the composition of naturally occurring substances such as complex vegetable oils and plant alkaloids...
, Farrington Daniels
Farrington Daniels
Farrington Daniels , was an American physical chemist, is considered one of the pioneers of the modern direct use of solar energy.- Biography :Daniels was born in Minneapolis, Minnesota on March 8, 1889...
, Frank C. Whitmore
Frank C. Whitmore
Frank Clifford Whitmore , nicknamed "Rocky", was a prominent chemist who submitted significant evidence for the existence of carbocation mechanisms in organic chemistry.He was born in 1887 in the town of North Attleborough, Massachusetts....
, James B. Sumner
James B. Sumner
James Batcheller Sumner was an American chemist. He shared the Nobel Prize in Chemistry in 1946 with John Howard Northrop and Wendell Meredith Stanley.-Biography:...
and James Bryant Conant
James Bryant Conant
James Bryant Conant was a chemist, educational administrator, and government official. As thePresident of Harvard University he reformed it as a research institution.-Biography :...
. Adams was particularly influential through Bolton's career. They shared diverse interests, yet a drive for accomplishment in organic chemistry. In later years Adams had significant influence on Bolton's ideas about industrial support of chemical research and university students.
In 1913 Bolton won the Sheldon Fellowship, which he used to work at the Kaiser Wilhelm Institut outside of Berlin, Germany for two years with Professor Richard Willstätter
Richard Willstätter
Richard Martin Willstätter was a German organic chemist whose study of the structure of plant pigments, chlorophyll included, won him the 1915 Nobel Prize for Chemistry. Willstätter invented paper chromatography independently of Mikhail Tsvet.-Biography:Willstätter was born in to a Jewish family...
. Here he worked on anthocyanins, a major program for Willstätter, and published three papers on isolation and structures of anthocyanin
Anthocyanin
Anthocyanins are water-soluble vacuolar pigments that may appear red, purple, or blue according to pH...
pigments. Willstätter, apparently impressed by Bolton's ability but frustrated by his tendency to make arithmetic mistakes, commented "You must have been a bank teller." To his surprise Bolton replied that he had been a bank teller, this was how he paid his way through college.
Bolton was very impressed by Willstätter's careful, logical approach to tackling a research problem. He felt that this was the result of good training in the German university system. He also observed the relationship between German universities and industry, for which there was no counterpart in the United States. Another aspect of German research that impressed Bolton was the effort to create artificial rubber. This work was significant to German industry, and later to the German war effort in World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
because Germany did not have ready access to sources of natural rubber. Also, the approach being used by the Germans undoubtedly lead to the development of neoprene rubber years later at DuPont Labs.
Bolton married Margarite L. Duncan in 1916 and they had three children, a daughter and two sons. He retired from DuPont after a distinguished career in 1951, but continued to follow the scientific literature. He died July 30, 1968 at the age of eighty-two.
World War I and DuPont
Up to the onset of World War IWorld War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...
(1914) most organic compounds had been imported from Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
, but disruptions caused by the War presented an opportunity for American chemical companies to become established in this area, and to meet a wartime need. When Bolton returned from Germany in 1915 he discovered American organic chemists struggling to develop methods for manufacturing these compounds. The Dupont Company needed chemists, and hired Bolton in 1915.
Bolton joined the Chemical Department at the Experimental Station outside Wilmington
Wilmington, Delaware
Wilmington is the largest city in the state of Delaware, United States, and is located at the confluence of the Christina River and Brandywine Creek, near where the Christina flows into the Delaware River. It is the county seat of New Castle County and one of the major cities in the Delaware Valley...
, Delaware
Delaware
Delaware is a U.S. state located on the Atlantic Coast in the Mid-Atlantic region of the United States. It is bordered to the south and west by Maryland, and to the north by Pennsylvania...
, where most of DuPont's research was conducted. Being groomed for advancement, he started working on the synthesis of glycerol. By 1916 Bolton was selected to lead the Dye
Dye
A dye is a colored substance that has an affinity to the substrate to which it is being applied. The dye is generally applied in an aqueous solution, and requires a mordant to improve the fastness of the dye on the fiber....
Group that was newly formed to research the synthesis of dyes. The United States had little knowledge of dye manufacture at this time, so later in 1916 Bolton traveled to England to learn about British technology in this area, and upon return he was assigned to the Wilmington Office to be advisor on dyes and intermediates. In 1918 he transferred to the Dyestuffs Department and was assistant general manager of the Lodi Works where silk colorants were made. In 1919 he returned to the Chemical Department as manager of the Organic Division. During this time he learned much about developing manufacturing processes and developed two principles; that high priority must be given to cost and time effectiveness of research, and that a manufacturing process should be perfected using pure materials, then later adapted to use materials available to the plant. Bolton's friend from Harvard, Roger Adams shared much of Bolton's philosophy in his work at the University of Illinois at Urbana-Champaign
University of Illinois at Urbana-Champaign
The University of Illinois at Urbana–Champaign is a large public research-intensive university in the state of Illinois, United States. It is the flagship campus of the University of Illinois system...
.
In 1922 DuPont reorganized its research by dividing the entire research enterprise into four parts, each assigned to one of its four production areas. Bolton was made director of research for the Dyestuffs Department where his ability in this capacity was quickly realized. Dye manufacture requires the synthesis of a large number of intermediate compounds, and Bolton realized these could be used in many activities outside the Dyestuffs Department. By 1923 his lab was working on accelerators for manufacture of synthetic rubber
Synthetic rubber
Synthetic rubber is is any type of artificial elastomer, invariably a polymer. An elastomer is a material with the mechanical property that it can undergo much more elastic deformation under stress than most materials and still return to its previous size without permanent deformation...
and soon after extended the research to include antioxidants for gasoline and rubber, floatation agents, insecticides, seed disinfectants, and large scale manufacture of tetra-ethyl lead
Tetra-ethyl lead
Tetraethyllead , abbreviated TEL, is an organolead compound with the formula 4Pb. An inexpensive additive, its addition to gasoline from the 1920's allowed octane ratings and thus engine compression to be boosted significantly, increasing power and fuel economy...
.
The Stevenson Act and Synthetic Rubber
In the early 1920s the supply and demand of natural rubber became a concern in international trade. In November 1922 England enacted the Stevenson Act that was intended to protect rubber producers by restricting production. This caused a great deal of concern in the United States because an expanding supply of rubber was needed to support the growing number of automobiles in use. Bolton saw this as an opportune time to start research on synthetic rubber. However, research did not begin in earnest until 1925 when the high price of rubber was attracting considerable attention and other scientists such as Thomas EdisonThomas Edison
Thomas Alva Edison was an American inventor and businessman. He developed many devices that greatly influenced life around the world, including the phonograph, the motion picture camera, and a long-lasting, practical electric light bulb. In addition, he created the world’s first industrial...
were also taking an interest in the problem.
Work on synthetic rubber began with the polymerization
Polymerization
In polymer chemistry, polymerization is a process of reacting monomer molecules together in a chemical reaction to form three-dimensional networks or polymer chains...
of butadiene obtained from the hydrogenation
Hydrogenation
Hydrogenation, to treat with hydrogen, also a form of chemical reduction, is a chemical reaction between molecular hydrogen and another compound or element, usually in the presence of a catalyst. The process is commonly employed to reduce or saturate organic compounds. Hydrogenation typically...
of diacetylene
Diacetylene
Diacetylene , with the formula C4H2, is a highly unsaturated hydrocarbon that contains three single bonds and two triple bonds. It is the first in the series of polyynes.-Occurrence:...
, and at first not much progress was made. At the end of 1925 Bolton met chemist Julius Arthur Nieuwland from the University of Notre Dame
University of Notre Dame
The University of Notre Dame du Lac is a Catholic research university located in Notre Dame, an unincorporated community north of the city of South Bend, in St. Joseph County, Indiana, United States...
who had discovered a way to polymerize acetylene
Acetylene
Acetylene is the chemical compound with the formula C2H2. It is a hydrocarbon and the simplest alkyne. This colorless gas is widely used as a fuel and a chemical building block. It is unstable in pure form and thus is usually handled as a solution.As an alkyne, acetylene is unsaturated because...
using a cuprous oxide catalyst. Unfortunately the resulting polymer would explode when struck, but Bolton believed the process could be modified to produce a stable compound that would replace butadiene in the reaction. Bolton brought Nieuwland into the project as a consultant to DuPont, and Nieuwland taught the DuPont chemists how to use his catalyst. A continuous-flow reactor was developed that would produce a good yield of the stable polymer Bolton was seeking. While the polymer was highly chemical resistant, it degraded with exposure to light.
In 1927 DuPont's Chemical Director C.M.A. Stine persuaded the company to take on a fundamental research project for synthetic rubber and received $250,000 in funding for this purpose. In 1928 Wallace Carothers
Wallace Carothers
Wallace Hume Carothers was an American chemist, inventor and the leader of organic chemistry at DuPont, credited with the invention of nylon....
, an instructor at Harvard University, was hired to lead the newly formed group. Bolton operated within this group and by 1929 had discovered that his polymer could be readily converted into 2-chlorobutadiene (chloroprene
Chloroprene
Chloroprene is the common name for the organic compound 2-chlorobuta-1,3-diene, which has the formula CH2=CCl-CH=CH2. This colorless liquid is the monomer for the production of the polymer polychloroprene, a type of synthetic rubber...
) with a copper catalyzed addition of hydrogen chloride
Hydrogen chloride
The compound hydrogen chloride has the formula HCl. At room temperature, it is a colorless gas, which forms white fumes of hydrochloric acid upon contact with atmospheric humidity. Hydrogen chloride gas and hydrochloric acid are important in technology and industry...
. This material was both chemical and light resistant, with the properties of a synthetic rubber.
The new material was announced at the Rubber Division of the American Chemical Society
American Chemical Society
The American Chemical Society is a scientific society based in the United States that supports scientific inquiry in the field of chemistry. Founded in 1876 at New York University, the ACS currently has more than 161,000 members at all degree-levels and in all fields of chemistry, chemical...
on November 2, 1931, and was called Duprene (today it is called neoprene
Neoprene
Neoprene or polychloroprene is a family of synthetic rubbers that are produced by polymerization of chloroprene. Neoprene in general has good chemical stability, and maintains flexibility over a wide temperature range...
). By this time the Stevenson Act had been repealed and the Great Depression
Great Depression
The Great Depression was a severe worldwide economic depression in the decade preceding World War II. The timing of the Great Depression varied across nations, but in most countries it started in about 1929 and lasted until the late 1930s or early 1940s...
had begun. Rubber prices were low and the new material cost twenty times what natural rubber cost. Therefore it never became a substitute for natural rubber, but it did find commercial use in applications where a rubber compound was needed that was more resistant to oils and outdoor degradation. Applications of neoprene include: the Rigid-hulled inflatable boat
Rigid-hulled inflatable boat
A rigid-hulled inflatable boat, or rigid-inflatable boat is a light-weight but high-performance and high-capacity boat constructed with a solid, shaped hull and flexible tubes at the gunwale. The design is stable and seaworthy...
; diving suit
Diving suit
A diving suit is a garment or device designed to protect a diver from the underwater environment. A diving suit typically also incorporates an air-supply .-History:...
s, and diveskins; glove
Glove
A glove is a garment covering the hand. Gloves have separate sheaths or openings for each finger and the thumb; if there is an opening but no covering sheath for each finger they are called "fingerless gloves". Fingerless gloves with one large opening rather than individual openings for each...
s, balaclavas, sleepsacks, Knee high boots, wetsocks and other protective clothing; radar absorbent material
Stealth technology
Stealth technology also termed LO technology is a sub-discipline of military tactics and passive electronic countermeasures, which cover a range of techniques used with personnel, aircraft, ships, submarines, and missiles, to make them less visible to radar, infrared, sonar and other detection...
; plumbing fixture
Plumbing fixture
A plumbing fixture is an exchangeable device which can be connected to an existing plumbing system to deliver and drain away water but which is also configured to enable a particular use.-Common fixtures:The most common plumbing fixtures are:*Bathtubs...
s; gaskets, hose
Hose (tubing)
A hose is a hollow tube designed to carry fluids from one location to another. Hoses are also sometimes called pipes , or more generally tubing...
s, seal
Seal (mechanical)
A mechanical seal is a device which helps join systems or mechanisms together by preventing leakage , containing pressure, or excluding contamination...
s and belt
Belt (mechanical)
A belt is a loop of flexible material used to link two or more rotating shafts mechanically. Belts may be used as a source of motion, to transmit power efficiently, or to track relative movement. Belts are looped over pulleys. In a two pulley system, the belt can either drive the pulleys in the...
s; foam
Foam
-Definition:A foam is a substance that is formed by trapping gas in a liquid or solid in a divided form, i.e. by forming gas regions inside liquid regions, leading to different kinds of dispersed media...
(mousepad
Mousepad
A mousepad or mouse mat is a surface for enhancing the usability of a computer mouse.-History:During a 1968 presentation by Douglas Engelbart marking the public debut of a mouse,...
, wetsuit
Wetsuit
A wetsuit is a garment, usually made of foamed neoprene, which is worn by surfers, divers, windsurfers, canoeists, and others engaged in water sports, providing thermal insulation, abrasion resistance and buoyancy. The insulation properties depend on bubbles of gas enclosed within the material,...
); orthopedic braces; and solid fuel rocket propellant (see AGM-114 Hellfire
AGM-114 Hellfire
The AGM-114 Hellfire is an air-to-surface missile developed primarily for anti-armor use. It has multi-mission, multi-target precision-strike capability, and can be launched from multiple air, sea, and ground platforms. The Hellfire missile is the primary 100 lb-class air-to-ground precision...
).
Synthetic Fibers
When Wallace Carothers arrived at DuPont in 1928 one of the tasks his group took on was the development of synthetic fibers for textiles. At that time a number of natural polymers such as latexLatex
Latex is the stable dispersion of polymer microparticles in an aqueous medium. Latexes may be natural or synthetic.Latex as found in nature is a milky fluid found in 10% of all flowering plants . It is a complex emulsion consisting of proteins, alkaloids, starches, sugars, oils, tannins, resins,...
and celluloid
Celluloid
Celluloid is the name of a class of compounds created from nitrocellulose and camphor, plus dyes and other agents. Generally regarded to be the first thermoplastic, it was first created as Parkesine in 1862 and as Xylonite in 1869, before being registered as Celluloid in 1870. Celluloid is...
were known and some synthetic polymers such as bakelite were also known and relatively common. The General Bakelite Company company was producing about 200,000 tons of Bakelite annually. Unfortunately the existing polymers could not be drawn into fibers and spun into thread, so the opportunity was to manufacture thread
Yarn
Yarn is a long continuous length of interlocked fibres, suitable for use in the production of textiles, sewing, crocheting, knitting, weaving, embroidery and ropemaking. Thread is a type of yarn intended for sewing by hand or machine. Modern manufactured sewing threads may be finished with wax or...
from synthetic polymers to replace natural fibers such as cotton
Cotton
Cotton is a soft, fluffy staple fiber that grows in a boll, or protective capsule, around the seeds of cotton plants of the genus Gossypium. The fiber is almost pure cellulose. The botanical purpose of cotton fiber is to aid in seed dispersal....
.
The approach taken by Carothers' group was to adapt known synthesises that produced short chain polymers to produce long chain molecules. The first break was finding that bifunctional esterification could produce long molecule chains which today are known as aliphatic polyester
Polyester
Polyester is a category of polymers which contain the ester functional group in their main chain. Although there are many polyesters, the term "polyester" as a specific material most commonly refers to polyethylene terephthalate...
s, but at that time were called superpolymers. Then there was the key observation by Julian W. Hill in April, 1930 in which it was seen that the superpolymers could be drawn in the molten state to form thin, transparent fibers that were much stronger that the polymers were in the undrawn state. However, the superpolymers the group was able to synthesize either had too low a boiling point and insufficient chemical resistivity or had too high a melting point to be spun. By late 1932 the entire project was discontinued.
Bolton, now the Chemistry department director, refused to give up. Most likely he was aware of the re-discovery of polyethylene
Polyethylene
Polyethylene or polythene is the most widely used plastic, with an annual production of approximately 80 million metric tons...
by Eric Fawcett
Eric Fawcett
Eric Fawcett , was a professor of physics at the University of Toronto for 23 years. He also co-founded Science for Peace.- Academic and Professional Life :...
and Reginald Gibson at Imperial Chemical Industries
Imperial Chemical Industries
Imperial Chemical Industries was a British chemical company, taken over by AkzoNobel, a Dutch conglomerate, one of the largest chemical producers in the world. In its heyday, ICI was the largest manufacturing company in the British Empire, and commonly regarded as a "bellwether of the British...
in 1933. In early 1934 Bolton urged Carothers to continue the research, and Carothers decided to take another look at polyamides.
Carothers surmised that the problem with the polyamides that had been made from ε-aminocaproic acid
Aminocaproic acid
Aminocaproic acid is a derivative and analogue of the amino acid lysine, which makes it an effective inhibitor for enzymes that bind that particular residue. Such enzymes include proteolytic enzymes like plasmin, the enzyme responsible for fibrinolysis...
was due to cyclization reactions, so he replaced ε-aminocaproic acid
Aminocaproic acid
Aminocaproic acid is a derivative and analogue of the amino acid lysine, which makes it an effective inhibitor for enzymes that bind that particular residue. Such enzymes include proteolytic enzymes like plasmin, the enzyme responsible for fibrinolysis...
with 9-aminononoic acid which would not cyclize. This produced results that were encouraging, so Carother's group prepared polyamides from a variety of compounds including amino acids, dibase acids and diamine
Diamine
A diamine is a type of polyamine with exactly two amino groups. Diamines are mainly used as monomers to prepare polyamides, polyimides and polyureas. In terms of quantities produced, 1,6-diaminohexane, a precursor to Nylon 6-6, is most important, followed by ethylenediamine...
s. The leading candidate for development became 5/10 polyamide made from pentamethylenediamine and sebic acid. It had the right melting point, the desired properties in fiber form and could be spun
Spun
Spun is a 2002 American crime dramedy directed by Jonas Åkerlund, and starring Jason Schwartzman, Brittany Murphy, Mickey Rourke, Mena Suvari, John Leguizamo, Patrick Fugit, Eric Roberts, Chloe Hunter, and Debbie Harry. It is Åkerlund's début as a feature-film director, having already become known...
without gel
Gel
A gel is a solid, jelly-like material that can have properties ranging from soft and weak to hard and tough. Gels are defined as a substantially dilute cross-linked system, which exhibits no flow when in the steady-state...
formation.
Bolton at this point made a bold and characteristically visionary decision. He decided that practical synthetic fibers could not be made from castor oil
Castor oil
Castor oil is a vegetable oil obtained from the castor bean . Castor oil is a colorless to very pale yellow liquid with mild or no odor or taste. Its boiling point is and its density is 961 kg/m3...
, the only practical source of sebacic acid
Sebacic acid
Sebacic acid is a dicarboxylic acid with structure 8, and is naturally occurring.In its pure state it is a white flake or powdered crystal...
. To use an agricultural product as a primary feedstock would mean the new synthetic material would have very similar mass production problems as existing natural fibers had. Instead he wanted to use benzene
Benzene
Benzene is an organic chemical compound. It is composed of 6 carbon atoms in a ring, with 1 hydrogen atom attached to each carbon atom, with the molecular formula C6H6....
as the feedstock for making both adipic acid
Adipic acid
Adipic acid is the organic compound with the formula 42. From the industrial perspective, it is the most important dicarboxylic acid: About 2.5 billion kilograms of this white crystalline powder are produced annually, mainly as a precursor for the production of nylon...
and hexamethylenediamine
Hexamethylenediamine
Hexamethylenediamine is the organic compound with the formula H2N6NH2. The molecule is a diamine, consisting of a hexamethylene hydrocarbon chain terminated with amine functional groups. The colorless solid has a strong amine odor, similar to piperidine...
to make a 6/6 polyamide.
This polymer was first made early in 1935, and thanks to concurrent development of polyamine spinning technologies, could be spun into fibers. The fibers had high strength and elasticity, were insensitive to common solvents and melted at 263 °C, well above ironing temperatures.
Bolton insisted that every aspect of the synthesis of this polymer be thoroughly worked out in a pilot plant at the Experimental Station. He insisted that the development begin with pure materials then be adapted to use materials available to a plant in bulk.
On October 27, 1938 DuPont announced it would build a plant at Seaford, Delaware
Seaford, Delaware
Seaford is a city located along the Nanticoke River in Sussex County, Delaware. According to the 2010 Census Bureau figures, the population of the city is 6,928, an increase of 3.4% from the 2000 census...
to make nylon
Nylon
Nylon is a generic designation for a family of synthetic polymers known generically as polyamides, first produced on February 28, 1935, by Wallace Carothers at DuPont's research facility at the DuPont Experimental Station...
, the world's first fully synthetic fiber. The Seaford plant was essentially a scaled up version of the pilot plant, and had remarkably trouble-free startup.
Publications
- E.K. Bolton, Development of Nylon, Industrial and Engineering Chemistry, (Jan 1942)
- Twenty-one U.S. Patents
Awards and honors
Bucknell UniversityBucknell University
Bucknell University is a private liberal arts university located alongside the West Branch Susquehanna River in the rolling countryside of Central Pennsylvania in the town of Lewisburg, 30 miles southeast of Williamsport and 60 miles north of Harrisburg. The university consists of the College of...
:
- Honorary D.Sc. degree (1932)
- Board of Trustees (1937-1967)
- Trustee Emeritus (1967-1968)
- University of DelawareUniversity of DelawareThe university is organized into seven colleges:* College of Agriculture and Natural Resources* College of Arts and Sciences* Alfred Lerner College of Business and Economics* College of Earth, Ocean and Environment* College of Education and Human Development...
, Honorary D.Sc. degree (1942) - Massachusetts Institute of TechnologyMassachusetts Institute of TechnologyThe Massachusetts Institute of Technology is a private research university located in Cambridge, Massachusetts. MIT has five schools and one college, containing a total of 32 academic departments, with a strong emphasis on scientific and technological education and research.Founded in 1861 in...
visiting committees (1938-1939) - Harvard UniversityHarvard UniversityHarvard University is a private Ivy League university located in Cambridge, Massachusetts, United States, established in 1636 by the Massachusetts legislature. Harvard is the oldest institution of higher learning in the United States and the first corporation chartered in the country...
visiting committees (1940-1941) - American Chemical SocietyAmerican Chemical SocietyThe American Chemical Society is a scientific society based in the United States that supports scientific inquiry in the field of chemistry. Founded in 1876 at New York University, the ACS currently has more than 161,000 members at all degree-levels and in all fields of chemistry, chemical...
: - regional director (1936-1938)
- director-at-large (1940-1943)
- Industrial and Engineering Chemistry and Chemical Engineering News Advisory Board (1948-1949)
- The Chemical Industry Medal (1941)
- The Perkin MedalPerkin MedalThe Perkin Medal is an award given annually by the American section of the Society of Chemical Industry to a scientist residing in America for an "innovation in applied chemistry resulting in outstanding commercial development." It is considered the highest honor given in the US industrial chemical...
(1945) - Elected to the National Academy of SciencesUnited States National Academy of SciencesThe National Academy of Sciences is a corporation in the United States whose members serve pro bono as "advisers to the nation on science, engineering, and medicine." As a national academy, new members of the organization are elected annually by current members, based on their distinguished and...
(1946) - The Willard Gibbs Medal (1954)