"Carothers equation In step-growth polymerization, the Carothers equation (or Carothers' equation) gives the degree of polymerization, ""X"", for a given fractional monomer conversion, ""p"". There are several versions of this equation, proposed by Wallace Carothers who invented nylon in 1935. The simplest case refers to the formation of a strictly linear polymer by the reaction (usually by condensation) of two monomers in equimolar quantities. An example is the synthesis of nylon-6,6 whose formula is [-NH-(CH)-NH-CO-(CH)-CO-] from one mole of hexamethylenediamine, HN(CH)NH, and one mole of adipic acid, HOOC-(CH)-COOH. For this case In this equation This equation shows that a high"
"synthetic rubber. In April 1930, one of Carothers' staff, Dr. Arnold M. Collins, isolated chloroprene, a liquid which polymerized to produce a solid material that resembled rubber. This product was the first synthetic rubber and is known today as Neoprene. In the same year, Dr. Julian W. Hill, another member of the Carothers team, began work again on attempting to produce a polyester with a molecular weight of above 4,000. His efforts were soon met with great success when he produced a synthetic polymer with a molecular weight of about 12,000. The high molecular weight allowed the melted polymer to"
"Carother's group in early February and had previously worked with divinyl acetylene while at the Jackson Laboratory. Chloroprene, now known as neoprene, was the first synthetic rubber. DuPont marketed the product under the name DuPrene in 1931. Wallace Carothers' group at the DuPont Experimental Station had been utilizing condensation polymerizations to make polyesters. But, the fibers made under this process would melt at low temperatures and were soluble in common solvents and were therefore not suitable as commercial products. Carothers' group instead turned their attention to using diacidic and dibasic molecules in order to create polyamide fibers. After several repeated"
"and other elements, it was possible to create new compounds by design and industrial chemistry was born. Two decades after the world's first plastic – Bakelite – had been invented in 1907, Wallace Carothers successfully drew off a fibre from the interface of two liquids: hexane-1,6-diamine and decanedioyl-dichloride, which could be spun into a very fine, very strong thread. It was given the name nylon. Shockingly, only three weeks after the patent for nylon had been filed, a depressed Carothers slipped another carbon based compound into his own drink, potassium cyanide, and killed himself. Evidently, industrial chemistry wasn’t without its"
"He was very successful as research he undertook greatly improved the knowledge of polymers and contributed to science. In the spring of 1930, Carothers and his team had already synthesized two new polymers. One was neoprene, a synthetic rubber greatly used during World War II. The other was a white elastic but strong paste that would later become nylon. After these discoveries Carother’s team was made to shift its research from a more pure research approach investigating general polymerization to a more practically-focused goal of finding “one chemical combination that would lend itself to industrial applications”. It wasn’t until the"
"find a synthetic alternative to natural silk fiber. Carothers, by eliminating water on a continuous distillation process, obtained polymers with molar masses significantly higher than what was previously synthesized. Nevertheless, the properties of the final products did not show the expected qualities. Thus Carothers put more attention on polyamides and invented with his colleague Julian Hill Nylon 6,6. Later Flory (1946) proposed an improved synthesis of aliphatic polyesters with diacid chloride. In the beginning of the 1990s, after being forgotten for more than 40 years, these polymers received a renewed interest due to the increasing demand on biodegradable and bio-based"
"boots, wetsocks and other protective clothing; radar absorbent material; plumbing fixtures; gaskets, hoses, seals and belts; foam (mousepad, wetsuit); orthopedic braces; and solid fuel rocket propellant (""see AGM-114 Hellfire""). When Wallace Carothers arrived at DuPont in 1928 one of the tasks his group took on was the development of new synthetic fibers for textiles. At that time a number of natural polymers such as latex and cellulose were in common use, rayon as a semisynthetic from nitrated cellulose had recently been improved and begun upending the textile industries, and some fully synthetic polymers such as bakelite were also known and"
"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 diamines. The leading"
"problem from famed chemist Wallace Carothers who was also working at DuPont at the time. Within a week, Hanford and his two assistants had found a solution that yielded ninety-six percent of Carothers’ desired polymer. Solving this problem furthered Hanford's interest in polyamides and polyesters. He soon began to work with di-isocyanates by studying reactions that contained hydroxyl, carboxyl, amide, and amine components. On May 24, 1939, Hanford and Donald Holmes filed a patent titled “Process for Making Polymeric Products and for Modifying Polymeric Products.” This patent was the development that would eventually land Hanford in the Inventors Hall of"
"through a typical step-growth polymerization fashion of phenol and formaldehyde. The pioneer of synthetic polymer science, Wallace Carothers, developed a new means of making polyesters through step-growth polymerization in 1930s as a research group leader at DuPont. It was the first reaction designed and carried out with the specific purpose of creating high molecular weight polymer molecules, as well as the first polymerization reaction whose results had been predicted beforehand by scientific theory. Carothers developed a series of mathematic equations to describe the behavior of step-growth polymerization systems which are still known as the Carothers equations today. Collaborating with Paul"
"and Co. began research on large molecules and synthetic fibers. This early research, headed by W.H. Carothers, centered on what became nylon, which was the first synthetic fiber. Carothers was working for duPont at the time. Carother’s research was incomplete and had not advanced to investigating the polyester formed from mixing ethylene glycol and terephthalic acid. The project was revived by British scientists Whinfield and Dickson who patented PET or PETE in 1941. Polyethylene terephthalate forms the basis for synthetic fibers like Dacron, Terylene and polyester. In 1946, duPont bought all legal rights from Imperial Chemical Industries (ICI) In 1950."
"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"
"hiring of Wallace Carothers in 1928 and his systemization of polymer science that led to the development of polyamides such as nylon-6,6 and polychloroprene (neoprene) in the early 1930s. This tradition waned during World War II then underwent a renaissance in the 1950s. The establishment of Central Research in 1957 formalized a corporate commitment to basic research. The execution and publication of high quality research assisted recruiting and promoted the image of DuPont while raising morale among the CRD staff. The purpose of the research was to discover ""the next nylon"", because Carothers' success and the resulting commercialization of nylon"
"be stretched out into strings of fiber. Thus was created the first synthetic silk, described by the chemists as a superpolyester. Polyesters and polyamides are examples of condensation polymers formed by step-growth polymerization. Carothers worked out the theory of step-growth polymerization and derived the Carothers equation which relates the average degree of polymerization to the fractional conversion (or yield) of monomer into polymer. This equation shows that for a high molecular weight, a very high fractional conversion is needed (for step-growth polymers only). Hill also produced a synthetic fiber that was elastic and strong by combining glycols and diacids and"
"myself, even now, accepting incalculable benefits proffered out of sheer magnanimity and good will and failing to make even such trivial return as circumstances permit and human feeling and decency demand, out of obtuseness or fear or selfishness or mere indifference and complete lack of feeling."" Carothers began working at the DuPont Experimental Station on February 6, 1928. The synthesis of a polymer with a molecular weight of more than 4,200, the mass achieved by Dr. Emil Fischer, was his primary goal. By the summer of 1928, Carothers boasted a small staff of Ph.D. chemists and two consultants: Dr. Roger"
"department director Elmer Keiser Bolton. Carothers had been hired to perform pure research, and he worked to understand the new materials' molecular structure and physical properties. He took some of the first steps in the molecular design of the materials. His work led to the discovery of synthetic nylon fiber, which was very strong but also very flexible. The first application was for bristles for toothbrushes. However, Du Pont's real target was silk, particularly silk stockings. Carothers and his team synthesized a number of different polyamides including polyamide 6.6 and 4.6, as well as polyesters. It took DuPont twelve years"
"them to Wilmington. With no thought of the possible emotional ramifications of this move, he bought a house in Arden about from the Experimental Station and moved into it with his parents. He was 37 at the time. Interactions with his parents soon became tense. Carothers was still seeing Sylvia Moore, who was now single, and his parents greatly disapproved of the relationship. Finding the tension in the household too wearing, his parents returned to Des Moines in the spring of 1934. In 1934, Carothers turned his attention to fibers again. Now the team substituted diamines for glycols to produce"
"the finding of English chemist F. E. Matthews that polysulfones could be formed by the reaction of sulfur dioxide and ethylene, Marvel confirmed the finding, using cyclohexene rather than ethylene. He was a close friend as well as a consultant to Wallace Carothers, who was carrying out groundbreaking work on nylon and neoprene at Dupont. Marvel also consulted with Ray C. Houtz, when Houtz was developing a synthetic fiber made from polyacrylonitrile, Orlon. Marvel participated heavily in the U.S. synthetic rubber program when supplies of natural rubber were disrupted during World War II. The availability of rubber was essential to"
"of the compound occurs. Because hydrogen chloride readily combines with water vapor in the air to form hydrochloric acid, polyvinyl chloride is not recommended for long-term archival storage of silver, photographic film or paper (mylar is preferable). The plastics industry was revolutionized in the 1930s with the announcement of polyamide (PA), far better known by its trade name nylon. Nylon was the first purely synthetic fiber, introduced by DuPont Corporation at the 1939 World's Fair in New York City. In 1927, DuPont had begun a secret development project designated Fiber66, under the direction of Harvard chemist Wallace Carothers and chemistry"
"Adams, his thesis advisor, and Dr. Carl Marvel, his instructor of organic chemistry at the University of Illinois. The laboratory where these top scientists worked became known as ""Purity Hall"". It was discouraging that by the middle of 1929, ""Purity Hall"" had not produced a polymer with a weight of much over 4,000. In January 1930, Dr. Elmer K. Bolton became assistant chemical director in the chemical department, and thus, Carothers' immediate boss. Bolton wanted practical results in 1930, and his wish was fulfilled. Bolton asked Carothers to examine the chemistry of an acetylene polymer with the goal of creating"
"in the early 1950s. In 1937, Wallace Hume Carothers invented nylon. In 1946, he invented Polyester. polyethylene terephthalate (PET) bottles are made from ethylene and paraxylene. In 1938, Otto Bayer invented polyurethane. In 1941, Roy Plunkett invented Teflon. In 1949, Fritz Stastny turned polystyrene into foam. In 1965, Stephanie Kwolek invented Kevlar. The following is a partial list of the major commercial petrochemicals and their derivatives: Petrochemical Petrochemicals (also known as petroleum distillates) are chemical products derived from petroleum. Some chemical compounds made from petroleum are also obtained from other fossil fuels, such as coal or natural gas, or renewable"
"being used for certain applications, but the existing fully synthetic polymers could not be drawn into fibers and spun into thread, so great opportunity existed to manufacture thread and yarn from synthetic polymers to join or replace the existing fibers in the market (natural fibers such as cotton, wool, linen, and silk and artificial fiber in the various recently emerged types of rayon). The approach taken by Carothers' group was to adapt known syntheses 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"
"Pittacal Pittacal was the first synthetic dyestuff to be produced commercially. It was accidentally discovered in 1832 by German chemist Carl Ludwig Reichenbach, who is also recognized as being the discoverer of kerosene, phenol, eupion, paraffin wax and creosote. According to history, Reichenbach applied creosote to the wooden posts of his home, in order to drive away dogs who urinated on them. The strategy was ineffective, however, and he noted that the dog's urine reacted with creosote to form an intense dark blue deposit. He named the new substance píttacal (from Greek words ""tar"" and ""beautiful""). He later succeeded in"
"heating under reduced pressure, using a molecular still to remove the last traces of water produced in the condensation reaction. Unfortunately, the fiber produced could not be commercialized because it reverted to a sticky mass when placed in hot water. Carothers dropped his research on polymers for several years. In 1931, Carothers moved into a house in Wilmington, which became known as Whiskey Acres, with three other DuPont scientists. He was no recluse, but his depressive moods often prevented him from enjoying all the activities in which his roommates took part. In a letter to a close friend, Frances Spencer,"
"in 1933, said of Carothers: In his research, Dr. Carothers showed even at this time the high degree of originality which marked his later work. He was never content to follow the beaten path or to accept the usual interpretations of organic reactions. His first thinking about polymerization and the structure of substances of high molecular weight began while he was at Harvard. In 1927, DuPont decided to fund fundamental, pure research: research not deliberately aimed at the development of a money-making product. Carothers traveled to Wilmington, Delaware, to discuss the possibility of being in charge of organic chemistry at"
"in place of leather, which under wartime conditions was rationed. ""Presstoff"" could be used in almost every application normally filled by leather, excepting items like footwear that were repeatedly subjected to flex wear or moisture. Under these conditions ""Presstoff"" tends to delaminate and lose cohesion. ""Poromerics"" are made from a plastic coating (usually a polyurethane) on a fibrous base layer (typically a polyester). The term poromeric was coined by DuPont as a derivative of the terms ""porous"" and ""polymeric"". The first poromeric material was DuPont's Corfam, introduced in 1963 at the Chicago Shoe Show. Corfam was the centerpiece of the"
"Nick Manoloff invented the Nick Manoloff Tone Bar. He was granted a patent (#2073331) on March 9, 1937. The tone bar or steel was made of the revolutionary synthetic material known as bakelite. Bakelite (/ˈbeɪkəlaɪt/ BAY-kə-lyt, sometimes spelled Baekelite[3]), or polyoxybenzylmethylenglycolanhydride, is an early plastic. It is a thermosetting phenol formaldehyde resin, formed from an elimination reaction of phenol with formaldehyde. It was developed by Belgian-born chemist Leo Baekeland in New York in 1907. These slides were 2.75"" in length, 0.75"" in diameter, round on the tip end and flat on the other with inscription, ""Nick Manoloff Pat. 2076331."" They"
"excretion of lac beetles). Chemists had begun to recognize that many natural resins and fibres were polymers, and Baekeland investigated the reactions of phenol and formaldehyde. He first produced a soluble phenol-formaldehyde shellac called ""Novolak"" that never became a market success, then turned to developing a binder for asbestos which, at that time, was moulded with rubber. By controlling the pressure and temperature applied to phenol and formaldehyde, he found in 1905 he could produce his dreamed-of hard mouldable material (the world's first synthetic plastic): bakelite. He announced his invention at a meeting of the American Chemical Society on February"
"nature, although rare. Cadet's fuming liquid (impure cacodyl), often claimed as the first synthetic organometallic compound, was synthesized in 1760 by Louis Claude Cadet de Gassicourt by the reaction of potassium acetate with arsenic trioxide. In the Victorian era, ""arsenic"" (""white arsenic"" or arsenic trioxide) was mixed with vinegar and chalk and eaten by women to improve the complexion of their faces, making their skin paler to show they did not work in the fields. Arsenic was also rubbed into the faces and arms of women to ""improve their complexion"". The accidental use of arsenic in the adulteration of foodstuffs"
"producing pure pittacal by treating beechwood tar with barium oxide and using alumina as a mordant to the dye's fabrics. Although sold commercially as a dyestuff, it did not fare well. Eupittone (derived from eu- + pittacal + -one) is a yellow crystalline substance resembling aurin, and obtained by the oxidation of pittacal. It is also called also eupittonic acid or eupitton. Kaufmann, GB - Pittacal—the first synthetic dyestuff. ""J. Chem. Edu."", 753, 1977. Pittacal Pittacal was the first synthetic dyestuff to be produced commercially. It was accidentally discovered in 1832 by German chemist Carl Ludwig Reichenbach, who is also"
"Sorbothane Sorbothane is the brand name of a synthetic viscoelastic urethane polymer used as a shock absorber and vibration damper. It is manufactured by Sorbothane, Inc., based in Kent, Ohio. Sorbothane was invented and patented in 1982 by Dr. Maurice Hiles, a British inventor. It was prepared by mixing polyol and isocyanate. His research into the energy dissipation properties of human soft tissue disclosed a structure very similar to an interpenetrating polymer network. This led to his synthesis of the first commercial simultaneous interpenetrating network, now called Sorbothane. Dr. Hiles wrote in his patent ""The resulting solid polymer behaves like"
"Flory, a physical chemist, they developed theories that describe more mathematical aspects of step-growth polymerization including kinetics, stoichiometry, and molecular weight distribution etc. Carothers is also well known for his invention of Nylon. ""Step growth polymerization"" and condensation polymerization are two different concepts, not always identical. In fact polyurethane polymerizes with addition polymerization (because its polymerization produces no small molecules), but its reaction mechanism corresponds to a step-growth polymerization. The distinction between ""addition polymerization"" and ""condensation polymerization"" was introduced by Wallace Hume Carothers in 1929, and refers to the type of products, respectively: The distinction between ""step-growth polymerization"" and ""chain-growth"
"60% or more moles of the carboxylic acid portion of the repeating unit in the polymer chain is composed of a combination of terephthalic acid (TPA) and isophthalic acid (IPA). Wallace Carothers at DuPont patented nylon 66 using amides. In the case of nylons that involve reaction of a diamine and a dicarboxylic acid, it is difficult to get the proportions exactly correct, and deviations can lead to chain termination at molecular weights less than a desirable 10,000 daltons (u). To overcome this problem, a crystalline, solid ""nylon salt"" can be formed at room temperature, using an exact 1:1 ratio"