CAPROLACTAM
Caprolactam is a crystalline cyclic amide with the formula C6H11NO, primarily used as a precursor in the production of Nylon 6, a versatile synthetic polymer employed in textiles, automotive parts, and engineering plastics.
Caprolactam is produced mainly through the Beckmann rearrangement of cyclohexanone oxime, a process discovered by Otto Wallach, and has significant industrial applications due to its durability, resistance to abrasion, and elasticity.
Caprolactam, derived from ε-aminocaproic acid, is manufactured in large quantities annually and is crucial in creating high-strength fibers and resins for a wide range of end-use applications, from clothing to mechanical parts.
CAS Number: 105-60-2
EC Number: 203-313-2
Chemical Formula: C6H11NO
Molar Mass: 113.160 g·mol−1
Synonyms: Azepan-2-one, 1-Aza-2-cycloheptanone, 2-Azacycloheptanone, ε-Caprolactam, Capron PK4, Cyclohexanone iso-oxime, Extrom 6N, Hexahydro-2-azepinone, Hexahydro-2H-azepin-2-one (9CI), Hexanolactam, Hexano-6-lactam, Aminocaproic lactam, azepan-2-one, CAPROLACTAM, epsilon-Caprolactam, 105-60-2, 6-Caprolactam, 2-Oxohexamethylenimine, Aminocaproic lactam, 2H-Azepin-2-one, hexahydro-, 6-Hexanelactam, 2-Azacycloheptanone, Hexahydro-2H-azepin-2-one, 2-Oxohexamethyleneimine, Hexanolactam, 2-Perhydroazepinone, Hexahydro-2-azepinone, 1,6-Hexolactam, Hexanone isoxime, Caprolattame, 2-Ketohexamethylenimine, Cyclohexanone iso-oxime, E-Caprolactam, 1-Aza-2-cycloheptanone, Epsylon kaprolaktam, Hexanonisoxim, Kaprolaktam, 6-Aminocaproic acid lactam, Extrom 6N, hexannic acid, e-Kaprolaktam, Hexamethylenimine, 2-oxo-, Caprolactam monomer, 1,6-Hexalactam, 2-Ketohexamethyleneimine, Kapromine, Stilon, E-caprolactum, 6-Aminohexanoic acid cyclic lactam, Perhydroazepin-2-one, 2H-Azepin-7-one, hexahydro-, gamma-caprolactam, omega-caprolactum, Capron PK4, .epsilon.-Caprolactam, Hexanoic acid, 6-amino-, lactam, NCI-C50646, .omega.-Caprolactam, 2H-azepin-7-one,hexahydro, Hexanoic acid, 6-amino-, cyclic lactam, HSDB 187, EINECS 203-313-2, Lactam, aminocaproic, NSC 117393, hexanoic acid-6-amino-,lactam, BRN 0106934, DTXSID4020240, CHEBI:28579, AI3-14515, UNII-6879X594Z8, A1030, Caprolactam dust and vapor, cis-Hexahydro-2-azepinone, NSC-117393, hexahydro 2H Azepin 2 one, hexanoic acid-6-amino-lactam, DTXCID00240, 6879X594Z8, FEMA NO. 4235, 2-Azepinone, hexahydro-, (Z)-, EC 203-313-2, EPSILON-CAPROLACTAM-D10, 5-21-06-00444 (Beilstein Handbook Reference), Cyclohexanoneisooxime, Hexanoic acid, lactam, WLN: T7MVTJ, CAPROLACTAM (IARC), CAPROLACTAM [IARC], Hexanoic acid, cyclic lactam, CAPROLACTAM (USP-RS), CAPROLACTAM [USP-RS], 9012-16-2, HEXANOIC ACID,6-AMINO,LACTAM E-CAPROLACTAM, CAS-105-60-2, hexahydroazepin-2-one, ZINC ACEXAMATE IMPURITY D (EP IMPURITY), ZINC ACEXAMATE IMPURITY D [EP IMPURITY], MFCD00006936, caprolactim, Caprolactama, Caprolactame, Steelon, Stylon, 6-hexanolactam, hexannic acid, U-Caprolactam, hexano-6-lactam, Caprolactam Vapor, Caprolactam,(S), Caprolactam, Dust, epsilon caprolactam, Caprolactam (dust), Kaprolaktam (damp), 2-Azepanone #, epsilon -caprolactam, Tarnamid T 27, azacycloheptan-2-one, azacycloheptane-2-one, 6-CAPROLACTAN, Capron 8257, ?2-Oxohexamethylenimine, CLS (CHRIS Code), CAPROLACTAM [MI], CAPROLACTAM [HSDB], ATM 2(NYLON), bmse000372, epsilon-Caprolactam, 99%, 6-Aminohexanoic acid lactam, Hexahydro-2H-azepine-2-one, SCHEMBL19610, 6-amino-hexanoic acid lactam, 6- amino-hexanoic acid lactam, 2H-azepin-2-ona, hexahidro-, 1,6-Hexanolactam - dust only, CHEMBL276218, HEXAMETHYLENIMINE,2-OXO-, NIOSH/CM3900000, 1,6-HEXALACTAM [FHFI], e-Caprolactam (Dampf und Staub), NSC4977, e-Caprolactam, (dust and vapour), (C6-H11-N-O)x-, 2H-AZEPIN-2-ONE,HEXAHYDRO, NSC-4977, NSC25536, STR02412, Tox21_202202, Tox21_300163, 1,6-Hexanolactam - dust and vapour, c0432, LS-390, NSC-25536, NSC117393, STK378587, AKOS000119969, CS-T-50239, epsilon-Caprolactam, analytical standard, NCGC00247913-01, NCGC00247913-02, NCGC00253933-01, NCGC00259751-01, AM802872, LS-22987, CM39000000, FT-0623443, FT-0625676, EN300-19667, A23500, C06593, D70254, Q409397, J-510225, F0001-0110, InChI=1/C6H11NO/c8-6-4-2-1-3-5-7-6/h1-5H2,(H,7,8, 2H-Azepin-2-one, hexahydro-, ε-Caprolactam, ω-Caprolactam, Aminocaproic lactam, Hexahydro-2-azepinone, Hexahydro-2H-azepin-2-one, Hexanoic acid, 6-amino-, cyclic lactam, 2-Azacycloheptanone, 2-Ketohexamethylenimine, 2-Oxohexamethylenimine, 2-Perhydroazepinone, 6-Caprolactam, 6-Hexanelactam, 6-Aminohexanoic acid cyclic lactam, 1,6-Hexolactam, 2-Ketohexamethyleneimine, Caprolattame, Epsylon kaprolaktam, Hexamethylenimine, 2-oxo-, Hexanoic acid, 6-amino-, lactam, Hexanonisoxim, NCI-C50646, 1-Aza-2-cycloheptanone, 2H-Azepin-7-one, hexahydro-, A1030, Akulon, Alkamid, Amilan cm 1001, Amilan cm 1011, Amilan cm 1001C, Amilan cm 1001G, 6-Aminocaproic acid lactam, ATM 2(NYLON), Bonamid, Capran 80, Capran 77C, Caprolon B, Caprolon V, Capron, Capron 8250, Capron 8252, Capron 8253, Capron 8256, Capron 8257, Capron B, Capron GR 8256, Capron GR 8258, Capron PK4, Chemlon, CM 1001, CM 1011, CM 1031, CM 1041, Danamid, Dull 704, Durethan bk, Durethan bk 30S, Durethan bkv 30H, Durethan bkv 55H, Ertalon 6sa, Extrom 6N, Grilon, Hexanolactam, Itamid, Itamid 250, Itamide 25, Itamide 35, Itamide 250, Itamide 350, Itamide 250G, Itamide S, Kaprolit, Kaprolit B, Kaprolon, Kaprolon B, Kapromine, Kapron, Kapron A, Kapron B, Maranyl F 114, Maranyl F 124, Maranyl F 500, Metamid, Miramid H 2, Miramid wm 55, Nylon A1035sf, Nylon cm 1031, Nylon X 1051, Orgamide, Orgamid RMNOCD, 2-Oxohexamethyleneimine, PA 6, PK 4, PKA, Plaskin 8200, Plaskon 201, Plaskon 8201, Plaskon 8205, Plaskon 8207, Plaskon 8252, Plaskon 8202C, Plaskon 8201hs, Plaskon xp 607, Polyamide pk 4, Relon P, Renyl MV, Sipas 60, Spencer 401, Spencer 601, Steelon, Stilon, Stylon, Tarlon X-A, Tarlon XB, Tarnamid T, Tarnamid T 2, Tarnamid T 27, Torayca N 6, UBE 1022B, Ultramid B 3, Ultramid B 4, Ultramid B 5, Ultramid BMK, Vidlon, Widlon, Zytel 211, 6-Aminohexanoic acid lactam, Hexano-6-lactam, Azepan-2-one, 2-Azepanone, 117955-36-9, 2953-03-9, 34876-18-1, 168214-28-6, Aminocaproic lactam, epsilon-Caprolactam, Hexahydro-2H-azepin-2-one, 2-Oxohexamethylenimine, 2-Ketohexamethylenimine, Hexahydro-2-H-azepin-2-one, 6-Aminocaproiclactam, epsilon caprolactam, 2-Oxohexamethyleneimine, 6-Hexanelactam, aminocaproic lactam, epsilon-caprolactam, hexahydro-2H-azepin-2-one, 2-oxohexamethyleneimine, Hexahydro-2H-Azepin-2-one, 1-Aza-2-cycloheptanone, 2-Azacycloheptanone, 2-Ketohexamethylenimine, 2-Oxohexamethylenimine, 2-Perhydroazepinone, 6-Caprolactam, 6-Hexanelactam, A 19374, AP, AP (lactam), Aminocaproic Lactam, Azepan-2-one, Caprolactam, Hexahydro-1H-azepin-2-one, Hexahydro-2-azepinone, Hexahydro-2H-azepin-2-one, Hexano-6-lactam, 6-Amino-hexanoic Acid, Cyclic Lactam, Hexanolactam, NSC 117393, NSC 25536, NSC 4977, ω-Caprolactam
Caprolactam is an organic compound that serves as a critical precursor in the production of Nylon 6, a widely used synthetic polymer.
Structurally, caprolactam is a cyclic amide with the formula C6H11NO, and it appears as a colorless crystalline solid.
Caprolactam is produced mainly through the chemical reaction of cyclohexanone with hydroxylamine, followed by the Beckmann rearrangement of cyclohexanone oxime, which leads to the formation of caprolactam.
Caprolactam is of significant industrial importance because it undergoes polymerization to form Nylon 6, a versatile material used in various applications including textiles, carpets, automotive parts, and engineering plastics.
Caprolactam's durability, resistance to abrasion, and elasticity make it highly valuable in the manufacturing of fibers and industrial products such as tire cords and packaging films.
Despite its beneficial properties, caprolactam must be handled with care due to its potential health risks, including irritation to the skin, eyes, and respiratory system.
Additionally, environmental concerns arise from its production process, as caprolactam has the potential to pollute water sources if not carefully managed.
Due to its indispensable role in producing durable and high-performance materials, caprolactam remains a cornerstone in the global polymer industry, with ongoing research focused on improving its production efficiency and minimizing its environmental impact.
Caprolactam is a crystalline cyclic amide with a melting point of 70 °C.
Caprolactam is soluble in water, most oxygenated and chlorinated solvents, and some hydrocarbons.
Caprolactam derives its name from ε-aminocaproic acid, or 6-aminohexanoic acid; in principle, the lactam is formed when the terminal carboxylic acid and amino groups react to form the amide.
Caprolactam is an organic compound with the formula (CH2)5C(O)NH.
This colourless solid, Caprolactam, is a lactam (a cyclic amide) of caproic acid.
The amide formation reaction succeeds only when run in dilute solution; otherwise, aminocaproic acid polymerizes.
The commercial synthesis consists of the acid-catalyzed Beckmann rearrangement of cyclohexanone oxime, which was discovered by Prussian chemist and Nobel Prize winner Otto Wallach way back in 1900.
Numerous articles and patents have been devoted to improving this method ever since.
Wallach didn’t live to see it, but Caprolactam turned out to be extremely valuable.
In 1938, Paul Schlack at IG Farben found that heating caprolactam neat to 260 °C causes the ring to open and the terminal functional groups to react to form a long-chain polyamide.
This polymer later became known as “nylon 6”.
Caprolactam can be formed into high-strength fibers, resins, and films that have dozens of end-use applications ranging from clothing to violin strings to automotive mechanical parts.
Nylon 6 is similar to—but should not be confused with—nylon 6,6, which is prepared from hexamethylenediamine and adipic acid.
Caprolactam is registered under the REACH Regulation and is manufactured in and / or imported to the European Economic Area, at ≥ 1 000 000 to < 10 000 000 tonnes per annum.
Caprolactam derives its name from ε-aminocaproic acid, or 6-aminohexanoic acid; in principle, the lactam is formed when the terminal carboxylic acid and amino groups react to form the amide.
Caprolactam is the basic raw material for the production of polyamide 6, which is used thereafter in the textile or plastics industry.
Polyamide fibres have a very broad range of uses in the production of nylon and polycaprolactam mesh (perlon).
Its flexibility means that Caprolactam is used primarily in the production of sports clothing and other sporting equipment - e.g. for water sports, winter sports, or mountaineering and mountain climbing.
Caprolactam is readily biodegradable.
Caprolactam is a cyclic amide widely used as a chemical intermediate.
The main forms of Caprolactam are molten (liquid) and flakes.
At ambient temperatures, Caprolactam is a white, hygroscopic, crystalline solid.
Caprolactam is produced of benzene by synthetic method.
Caprolactam is produced via Beckmann rearrangement, which is the conversion of cyclohexanone to caprolactam through the oxime with the help of catalyst - sulphuric acid, which is the most commonly used acid for commercial lactam production.
Caprolactam is the feedstock in the production of Nylon 6.
Caprolactam is supplied in flake or fused form.
Caprolactam is the basic raw material for the production of polyamide 6, which is used thereafter in the textile or plastics industry.
Caprolactam quality of FACT Caprolactam is among the best available in the world.
Nitric Acid and Soda Ash - Small quantities of these are obtained from Caprolactam Plant as a by-product.
Early chemical processes for Caprolactam production needed complex distillation steps to clean the Caprolactam to a product quality which could be used for spinning.
The Snia Viscosa “I-The process” used toluene as feedstock which had been converted in a series of process steps to Caprolactam.
The raw Caprolactam solution was purified in a process stage with 6 Thin Film Evaporators.
“Unfortunately” state-of-the-art process designs usually do no longer need so many Thin Film Evaporators for Caprolactam purification.
Caprolactam is a crystalline cyclic amide with a melting point of 70 °C.
Caprolactam is soluble in water, most oxygenated and chlorinated solvents, and some hydrocarbons.
Caprolactam is an organic compound, this colourless solid is a lactam or a cyclic amide of caproic acid.
Approximately 4.5 billion kilograms are produced annually.
Caprolactam is the precursor to Nylon 6, a widely used synthetic polymer.
Firstly, Caprolactam was prepared by the cyclization of ε-aminocaproic acid, the product of the hydrolysis of caprolactam.
Given the commercial significance of Nylon-6, many methods have been developed for the production of caprolactam:
Most of the caprolactam is synthesised from cyclohexanone, which is first converted to its oxime.
Treatment of this oxime with acid induces the Beckmann rearrangement to give Caprolactam.
The immediate product of the acid-induced rearrangement is the bisulfate salt of Caprolactam.
This salt is neutralized with ammonia to release the free lactam and cogenerate ammonium sulfate.
In optimizing the industrial practices, much attention is directed toward minimizing the production of ammonium salts.
The other major industrial route involves formation of the oxime from cyclohexane using nitrosyl chloride.
The advantage of this method is that cyclohexane is less expensive than cyclohexanone.
The immediate product of the acid-induced rearrangement is the bisulfate salt of Caprolactam.
This salt is neutralized with ammonia to release the free lactam and cogenerate ammonium sulfate.
In optimizing industrial practices, much attention is directed toward minimizing the production of ammonium salts.
The other major industrial route involves formation of the oxime from cyclohexane using nitrosyl chloride.
The advantage of this method is that cyclohexane is less expensive than cyclohexanone.
Caprolactam is a white, crystalline solid or flakes with an unpleasant odor.
Caprolactam is a clear to milky white-colored solution with a mild, disagreeable odor.
Caprolactam is a member of the class of caprolactams that is azepane substituted by an oxo group at position.
Caprolactam has a role as a human blood serum metabolite.
Caprolactam is a natural product found in Vitis vinifera, Fagopyrum esculentum, and Nicotiana tabacum with data available.
Caprolactam is the raw material for Nylon 6 fiber and Nylon 6 resin.
Caprolactam is a synthetic precursor of Nylon-6 and other synthetic polymers.
Caprolactam also inhibits the growth of several Bacillus and Rhizobium species, but Arthrobacter species grow normally in the presence of Caprolactam.
Caprolactam is the main raw material for making nylon-6 fibers and resin.
Uses and Applications of Caprolactam:
Caprolactam is primarily utilized as a key raw material in the production of Nylon 6, a versatile synthetic polymer.
Caprolactam plays a pivotal role in the textile industry, where Nylon 6 fibers are spun into durable, high-performance fabrics for clothing, carpets, and upholstery.
Additionally, Caprolactam is used to manufacture industrial-grade materials such as tire cords, fishing lines, and ropes, prized for their strength and elasticity.
In the automotive sector, Caprolactam is employed in the production of lightweight yet robust components, including air intake manifolds and radiator end tanks, which contribute to improved fuel efficiency and vehicle performance.
Caprolactam-derived films and coatings offer excellent barrier properties for food packaging, enhancing shelf life and product safety.
Caprolactam's applications extend to engineering plastics used in mechanical parts, electrical insulators, and various consumer goods, showcasing its importance in both everyday products and specialized industrial applications.
In situ anionic polymerization is employed for cast nylon production where conversion from Caprolactam to Nylon 6 takes place inside a mold.
In conjunction with endless fiber processing the term thermoplastic resin transfer molding (T-RTM) is often used.
Caprolactam is also used in the synthesis of several pharmaceutical drugs including pentylenetetrazol, meptazinol, and laurocapram.
Caprolactam is used in the manufacture of synthetic fibers.
Release to the environment of Caprolactam can occur from industrial use: industrial abrasion processing with low release rate (e.g. cutting of textile, cutting, machining or grinding of metal).
Caprolactam is primarily used in the manufacture of synthetic fibers (especially Nylon 6).
Caprolactam is also used in brush bristles, textile stiffeners, film coatings, synthetic leather, plastics, plasticizers, paint vehicles, cross-linking for polyurethanes, and in the synthesis of lysine.
Global demand for Caprolactam is approximately five million tons per year, and the vast majority is used to make Nylon 6 filament, fiber, and plastics.
Caprolactam is used by consumers, in articles, by professional workers (widespread uses), in formulation or re-packing, at industrial sites and in manufacturing.
Caprolactam is used in the following products: inks and toners, coating products, fillers, putties, plasters, modelling clay and paper chemicals and dyes.
Other release to the environment of Caprolactam is likely to occur from: indoor use (e.g. machine wash liquids/detergents, automotive care products, paints and coating or adhesives, fragrances and air fresheners) and outdoor use.
Other release to the environment of Caprolactam is likely to occur from: indoor use in long-life materials with low release rate (e.g. flooring, furniture, toys, construction materials, curtains, foot-wear, leather products, paper and cardboard products, electronic equipment) and outdoor use in long-life materials with low release rate (e.g. metal, wooden and plastic construction and building materials).
Caprolactam can be found in products with material based on: plastic (e.g. food packaging and storage, toys, mobile phones), fabrics, textiles and apparel (e.g. clothing, mattress, curtains or carpets, textile toys), plastic used for large surface area articles (e.g. construction and building materials for flooring, insulation), plastic used for toys and other articles intended for children’s use, including baby-bottles, plastic used for packaging (excluding food packaging), plastic used for articles intended for food contact (e.g. plastic dinner ware, food storage), plastic used for articles with intense direct dermal (skin) contact during normal use (e.g. handles, ball pens) and leather (e.g. gloves, shoes, purses, furniture).
Caprolactam is used in the following products: laboratory chemicals.
Caprolactam is used for the manufacture of: plastic products and textile, leather or fur.
Release to the environment of Caprolactam can occur from industrial use: formulation of mixtures.
Other release to the environment of Caprolactam is likely to occur from: indoor use (e.g. machine wash liquids/detergents, automotive care products, paints and coating or adhesives, fragrances and air fresheners).
Caprolactam is used in the following products: adhesives and sealants, coating products, fillers, putties, plasters, modelling clay, inks and toners, leather treatment products, polymers and textile treatment products and dyes.
Release to the environment of Caprolactam can occur from industrial use: formulation of mixtures and formulation in materials.
Caprolactam is used in the following products: polymers.
Caprolactam has an industrial use resulting in manufacture of another substance (use of intermediates).
Caprolactam is used for the manufacture of: chemicals and plastic products.
Release to the environment of Caprolactam can occur from industrial use: for thermoplastic manufacture, as processing aid, as an intermediate step in further manufacturing of another substance (use of intermediates), as processing aid, in processing aids at industrial sites and in the production of articles.
Release to the environment of Caprolactam can occur from industrial use: manufacturing of the substance.
Almost all Caprolactam is used as monomer in the production of polycaprolactam, also known as nylon 6.
Caprolactam is used Fibers, sheets, filaments and bristles made from nylon 6 can be used, in turn, in a broad range of products, including apparel and home furnishings; carpets; and industrial uses (tires, reinforced rubber products).
The uses and applications of Caprolactam may vary according to the product grade.
Commercial caprolactam is produced with high purity, where water is usually the main contaminant with concentrations around 0.1 wt.%.
Caprolactam can be used in the manufacture of other products, including 6-aminocaproic acid; caprolactam disulfide; hexamethyleneimine; polyamide 6 terpolymers; poly(ether-amide) elastomers; n-vinyl caprolactam and lysine.
Caprolactam is used for production of chemical fibers and strings from polyamide pitches.
Caprolactam is manufactured from raw materials such as Benzene, Sulphur (as Sulphur-di-oxide and Oleum), Ammonia, Carbon-di-oxide.
Caprolactam is used in manufacturing Nylon Tyre cord, Nylon filament yarn, Engineering plastics, etc.
Its flexibility means that Caprolactam is used primarily in the production of sports clothing and other sporting equipment - e.g. for water sports, winter sports, or mountaineering and mountain climbing.
Today Thin Film Evaporation is still used in the polymerisation of Caprolactam to Nylon 6.
The polymerisation delivers a product which contains monomer and oligomers and other products from the polymerisation reaction.
The monomers and the oligomers have to be extracted with water in order to avoid fibre breaking during spinning.
Other processes, such as the depolymerisation of waste chips also produce water which contains Caprolactam.
Due to the relatively high concentration and relatively high price of Caprolactam the recovery is an economical must for Nylon 6 producers.
Polyamide fibres have a very broad range of uses in the production of nylon and polycaprolactam mesh (perlon).
The major sectors of Caprolactam catered to are the Textile and Automobile Industries.
Caprolactam is the raw material for Nylon-6.
Caprolactam is mainly used for the production of polyamide 6 pellets as well as for N-Methylcaprolactam
Caprolactam is used in manufacture of synthetic fibers of the polyamide type.
Caprolactam is used in the manufacture of synthetic fibers.
Caprolactam is used to make other chemicals.
Caprolactam is used in manufacture of synthetic fibers and resins (Nylon 6) used in carpets, rugs, textiles, engineering plastics, tire cord, and plastic film.
Caprolactam is primarily used in the production of Nylon 6 but has several other industrial and commercial applications.
Here are Caprolactam's main uses:
Nylon 6 Production:
Textile Fibers:
Nylon 6 is a popular material for producing synthetic fibers used in clothing, carpets, and upholstery due to its durability, strength, and resistance to wear.
Industrial Fibers:
Nylon 6 is used in industrial applications like tire cords, fishing lines, and ropes because of its strength and elasticity.
Engineering Plastics:
Caprolactam , derived from caprolactam, is used to manufacture engineering plastics that are lightweight but strong, making them ideal for automotive components, electrical appliances, gears, and mechanical parts.
These plastics can withstand high stress, making them suitable for machinery parts.
Films and Packaging:
Caprolactam-based Nylon 6 films offer excellent barrier properties against oxygen and moisture, making them suitable for food packaging and industrial packaging materials.
These films are valued for their transparency, toughness, and flexibility.
Automotive Industry:
Caprolactam is used to make automotive parts like air intake manifolds, radiator end tanks, and under-the-hood components due to its heat resistance, mechanical strength, and lightweight properties, which help improve fuel efficiency.
Carpet Fibers:
Caprolactam-based Nylon 6 fibers are widely used in the production of carpets and rugs.
They offer excellent resistance to wear and tear, making them suitable for high-traffic areas in homes and commercial spaces.
Electronics:
Caprolactam is used in electronic components due to its excellent electrical insulation properties.
Caprolactam is often found in connectors, circuit breakers, and other parts where electrical insulation and mechanical durability are required.
Monofilaments:
Monofilament fibers made from Nylon 6 are used in brushes, fishing nets, fishing lines, and other products that require flexibility combined with strength.
Use and Occurrence:
Caprolactam is a cyclic amide, derived from epsilon-aminocaproic acid, from which nylon 6 is polymerized.
Caprolactam is a monomer primarily used in the manufacture of the synthetic polymer nylon 6, fibers and resins, synthetic leather, and as a polyurethane cross linker.
Nylon 6 (polycaprolactam) is used in the production of tire cords, carpeting, plastics, and food-packaging materials.
Synthesis And Production of Caprolactam:
Caprolactam was first described in the late 1800s when it was prepared by the cyclization of ε-aminocaproic acid, the product of the hydrolysis of caprolactam.
World demand for Caprolactam was estimated to reach five million tons per year for 2015. 90% of caprolactam produced is used to make filament and fiber, 10% for plastics, and a small amount is used as a chemical intermediate.
Due to Caprolactam's commercial significance, many methods have been developed for the production of caprolactam.
Caprolactam was estimated that 90% of all Caprolactam is synthesized from cyclohexanone, which is first converted to its oxime.
Treatment of this oxime with acid induces the Beckmann rearrangement to give caprolactam:
The Beckmann Rearrangement:
The immediate product of the acid-induced rearrangement is the bisulfate salt of Caprolactam.
This salt is neutralized with ammonia to release the free lactam and cogenerate ammonium sulfate.
In optimizing the industrial practices, much attention is directed toward minimizing the production of ammonium salts.
The other major industrial route involves formation of the oxime from cyclohexane using nitrosyl chloride, and this method accounts for 10% of world production.
The advantage of this method is that cyclohexane is less expensive than cyclohexanone.
Other paths to Caprolactam include the depolymerization of waste Nylon 6, and the reaction of caprolactone with ammonia.
At bench scale, the reaction between cyclohexanone with hydrazoic acid to give caprolactam in the Schmidt reaction has been reported.
Production Pathways of Caprolactam:
Caprolactam can be produced commercially from cyclohexanone, cyclohexane, or toluene as starting materials.
Most Caprolactam production is based on the cyclohexanone process.
To a lesser extent, caprolactam is produced commercially by the photonitrosation of cyclohexane or by nitrosation of cyclohexane carboxylic acid (derived from toluene) in the presence of sulfuric acid.
Ultimately, the main commercial processes employed for Caprolactam production are based on benzene or toluene from BTX (benzene, toluene, xylenes), and generate ammonium sulfate as a byproduct.
Process of Caprolactam:
Caprolactam production involves four major sections: (1) benzene hydrogenation; (2) cyclohexane oxidation; (3) oximation & Beckmann rearrangement; and (4) ammonium sulfate purification
Benzene hydrogenation:
First, dried benzene is reacted with hydrogen in two steps, in the presence of platinum-based and zinc-oxide catalysts, to form cyclohexane.
The intermediate is purified in two columns and hydrogen is recycled to the reactor.
Cyclohexane oxidation:
The cyclohexane is converted to a mixture of cyclohexanone and cyclohexanol by liquid-phase air oxidation in the presence of a soluble cobalt catalyst. Subsequently, the cyclohexanol in the mixture is converted to cyclohexanone by vapor-phase dehydrogenation in the presence of a copper-magnesium catalyst.
Oximation and Beckmann rearrangement:
Ammonia is oxidized by oxygen in the presence of steam, yielding nitric oxide, which is absorbed in a solution.
This nitric oxide is hydrogenated over a palladium catalyst, in the presence of dilute sulfuric acid, producing hydroxyl ammonium sulfate solution.
Caprolactam reacts with cyclohexanone in stirred reactors in series to form the oxime.
The heterogeneous outlet is neutralized with ammonia.
Finally, the cyclohexanone oxime is converted to caprolactam by Beckmann rearrangement, in the presence of oleum (concentrated sulfuric acid).
The product of the rearrangement, Caprolactam, is purified by neutralization, extraction in the presence of toluene, and distillation.
The Caprolactam melt is solidified and converted into flakes.
Ammonium sulfate purification:
The ammonium sulfate solution that is removed in the neutralization steps is concentrated by evaporation.
Then Caprolactam is crystallized, centrifuged from the mother liquor and dried.
History of Caprolactam:
Caprolactam has a fascinating history that traces back to the late 19th century, during a time of rapid advancement in organic chemistry.
Caprolactam was first synthesized by the German chemist Adolf von Baeyer in the 1890s, as part of his broader investigations into cyclic compounds and amides.
However, Caprolactam's potential wasn’t fully realized until much later.
In the 1930s, Caprolactam gained significant attention when researchers were searching for new synthetic materials, especially polymers that could be used to replace natural fibers like silk.
In 1938, Paul Schlack, a German chemist working for IG Farben, developed a process for the polymerization of caprolactam to create Nylon 6, a revolutionary synthetic fiber.
This discovery came shortly after the invention of Nylon 6,6 by Wallace Carothers at DuPont, but Nylon 6 had distinct properties and was easier to produce in large quantities.
Following World War II, caprolactam and Nylon 6 became integral to the global textile industry, and the demand for caprolactam surged as Nylon 6 found widespread applications in clothing, carpets, and industrial products.
Since then, caprolactam production has continued to expand, driven by advancements in manufacturing processes and the ever-growing demand for synthetic fibers and engineering plastics.
Handling and Storage of Caprolactam:
Handling:
Avoid contact with skin, eyes, and clothing.
Ensure good ventilation in the workspace to prevent inhalation of dust or fumes.
Prevent the formation of dust and aerosols, which can be irritants.
Do not eat, drink, or smoke while handling the substance.
Wear appropriate protective equipment (gloves, goggles, and respirators) when working with caprolactam.
Storage:
Store in tightly sealed containers in a cool, dry, and well-ventilated area.
Keep away from moisture, air, and direct sunlight.
Avoid storage near incompatible materials, such as strong acids, oxidizing agents, and bases.
Protect from physical damage to avoid leaks and spills.
Recommended storage temperature:
Ambient conditions (below 25°C/77°F).
Stability and Reactivity of Caprolactam:
Stability:
Caprolactam is generally stable under recommended handling and storage conditions.
Hygroscopic:
Absorbs moisture from the air, which can affect Caprolactam's quality.
Caprolactam can decompose when exposed to high temperatures or open flames, releasing toxic gases such as ammonia and nitrogen oxides (NOx).
Reactivity:
Reacts with strong acids and bases, leading to hydrolysis.
Avoid contact with strong oxidizing agents, which may cause violent reactions.
Polymerizes under specific conditions, especially with catalysts and heat.
First Aid Measures of Caprolactam:
Inhalation:
Move the person to fresh air immediately.
If breathing is difficult, provide oxygen. Seek medical attention if symptoms persist.
Skin Contact:
Wash thoroughly with soap and water for at least 15 minutes.
Remove contaminated clothing and seek medical attention if irritation develops.
Eye Contact:
Rinse the eyes thoroughly with water for at least 15 minutes, keeping the eyelids open.
Seek medical attention immediately.
Ingestion:
Do not induce vomiting.
Rinse the mouth with water and seek medical attention right away.
Never give anything by mouth to an unconscious person.
Symptoms of Exposure:
May include skin irritation, eye irritation, respiratory discomfort, coughing, and nausea.
Firefighting Measures of Caprolactam:
Suitable Extinguishing Media:
Use water spray, foam, dry chemical, or carbon dioxide (CO₂) to extinguish the fire.
Specific Hazards:
Caprolactam can emit toxic fumes under fire conditions, including ammonia and nitrogen oxides.
Protective Equipment for Firefighters:
Firefighters should wear full protective clothing, including self-contained breathing apparatus (SCBA).
Avoid inhalation of combustion products and toxic gases.
Fire and Explosion Hazards:
Caprolactam is combustible, and dust or vapor may form explosive mixtures with air.
Additional Information:
Fight fire from a safe distance and cool containers exposed to fire with water.
Accidental Release Measures of Caprolactam:
Personal Precautions:
Evacuate unnecessary personnel from the area.
Wear protective equipment, including gloves, goggles, and respirators, to avoid exposure.
Avoid breathing dust, vapors, or fumes.
Environmental Precautions:
Prevent caprolactam from entering waterways, drains, or sewers.
Containment and Clean-Up:
For solid spills:
Use non-sparking tools to sweep up the material into a suitable waste container.
For liquid spills:
Contain the spill with inert absorbent materials (sand, vermiculite) and place the waste in labeled containers for disposal.
Ventilate the area thoroughly after cleaning up the spill.
Exposure Controls / Personal Protection of Caprolactam:
Exposure Limits:
OSHA PEL: 5 mg/m³ (inhalable dust)
ACGIH TLV: 1 mg/m³ (inhalable fraction, vapor)
Engineering Controls:
Provide adequate ventilation, especially in enclosed areas.
Use local exhaust ventilation to keep airborne concentrations below permissible exposure limits.
Personal Protective Equipment (PPE):
Eye Protection:
Wear safety goggles or face shields to protect against splashes and dust.
Skin Protection:
Wear protective gloves (nitrile or neoprene) and protective clothing to prevent skin contact.
Respiratory Protection:
If exposure limits are exceeded, use a NIOSH-approved respirator (P95 or P100) for particulates and vapors.
Hygiene Measures:
Wash hands and face after handling the material and before eating or drinking.
Identifiers of Caprolactam:
Chemical formula: C6H11NO
Molar mass: 113.160 g·mol−1
CAS number: 105-60-2
EC index number: 613-069-00-2
EC number: 203-313-2
Hill Formula: C₆H₁₁NO
Molar Mass: 113.16 g/mol
HS Code: 2933 71 00
IUPAC Name: Azepan-2-one
Common Name: Caprolactam
CAS Number: 105-60-2
EC Number: 203-313-2
UN Number: UN 2215 (for transport and shipping)
PubChem CID: 7769
ChemSpider ID: 7481
Beilstein Registry Number: 1071263
RTECS Number: NJ0875000
SMILES: C1CCC(=O)NCC1
InChI: InChI=1S/C6H11NO/c8-6-4-2-1-3-5-7-6/h1-5H2,(H,7,8)
InChI Key: GHOKWGTUZJEAQD-UHFFFAOYSA-N
Properties of Caprolactam:
Appearance: White solid
Density: 1.01 g/cm3
Melting point: 69.2 °C (156.6 °F; 342.3 K)
Boiling point: 270.8 °C (519.4 °F; 544.0 K) at 1013.25 hPa
Solubility in water: 866.89 g/l (22 °C)
Vapor pressure: 8.10−8 mmHg (20°C)
Boiling point: 270.8 °C (1013 hPa)
Density: 1.020 g/cm3 (75 °C)
Explosion limit: 1.4 - 8 %(V)
Flash point: 152 °C DIN 51758
Ignition temperature: 395 °C DIN 51794
Melting Point: 68 - 71 °C
pH value: 7.0 - 8.5 (333 g/l, H₂O)
Vapor pressure: Bulk density: 500 - 550 kg/m3
Solubility: 4560 g/l
Molecular Weight: 113.16 g/mol
XLogP3: -0.1
Hydrogen Bond Donor Count: 1
Hydrogen Bond Acceptor Count: 1
Rotatable Bond Count: 0
Exact Mass: 113.084063974 g/mol
Monoisotopic Mass: 113.084063974 g/mol
Topological Polar Surface Area: 29.1Ų
Heavy Atom Count: 8
Complexity: 90.5
Isotope Atom Count: 0
Defined Atom Stereocenter Count: 0
Undefined Atom Stereocenter Count: 0
Defined Bond Stereocenter Count: 0
Undefined Bond Stereocenter Count: 0
Covalently-Bonded Unit Count: 1
Compound Is Canonicalized: Yes
Vapor Pressure: 0.008000 mmHg @ 25.00 °C.
Flash Point: 278.00 °F. TCC ( 136.67 °C. )
logP (o/w): -0.039 (est)
Soluble in: propylene glycol
water, 7.72E+05 mg/L @ 10 °C (exp)
Physical state: crystalline
Color: colorless
Odor: No data available
Melting point/freezing point:
Melting point/range: 68 - 71 °C - lit.
Initial boiling point and boiling range: 136 - 138 °C at 13 hPa - lit.
Flammability (solid, gas): No data available
Upper/lower flammability or explosive limits:
Upper explosion limit: 11,9 %(V)
Lower explosion limit: 1,6 %(V)
Flash point: 152 °C - closed cup
Autoignition temperature: No data available
Decomposition temperature: No data available
pH: 7,0 - 8,5 at 333 g/l
Viscosity
Viscosity, kinematic: No data available
Viscosity, dynamic: No data available
Water solubility: soluble
Partition coefficient: n-octanol/water:
log Pow: 0,12 at 25 °C
Vapor pressure: 9 hPa at 60 °C < 0,01 hPa at 20 °C
Specifications of Caprolactam:
Purity: ≥ 99.8% (high-grade caprolactam)
Water Content: ≤ 0.1%
Ash Content: ≤ 0.005% (to ensure minimal inorganic contaminants)
Permanganate Value: ≥ 15 minutes (indicates purity by oxidation resistance)
pH (5% solution): 7.0–8.0
Color: ≤ 5 APHA (low color number to ensure high clarity for polymers)
Melting Point: 68-70°C
Boiling Point: 260-270°C
Density: 1.02 g/cm³ (at 20°C)
Solubility in Water: Completely soluble at room temperature
Appearance: White crystalline solid or clear liquid at elevated temperatures
Odor: Slightly pungent, ammonia-like
Ammonium Ions (NH₄⁺): ≤ 5 ppm
Iron Content (Fe): ≤ 0.5 ppm
Color Compounds: Minimal to ensure clarity in final polymer products
Cyclic Dimer (Nylon 6 Dimer): ≤ 0.2% (to ensure optimal polymerization)
