Cuprammonium rayon is a rayon fiber made from

cellulose Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units. Cellulose is an important structural component of the primary cell w ...

dissolved in a

cuprammonium Schweizer's reagent is the metal ammine complex with the formula u(NH3)4(H2O)2OH)2. This deep-blue compound is used in purifying cellulose. It is prepared by precipitating copper(II) hydroxide from an aqueous solution of copper sulfate using so ...

solution,

Schweizer's reagent Schweizer's reagent is the metal ammine complex with the formula u(NH3)4(H2O)2OH)2. This deep-blue compound is used in purifying cellulose. It is prepared by precipitating copper(II) hydroxide from an aqueous solution of copper sulfate using so ...

. It is produced by making cellulose a soluble compound by combining it with

copper Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkis ...

and

ammonia Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous wa ...

with

caustic soda Sodium hydroxide, also known as lye and caustic soda, is an inorganic compound with the formula NaOH. It is a white solid ionic compound consisting of sodium cations and hydroxide anions . Sodium hydroxide is a highly caustic base and alkali ...

. The solution is passed through a

spinneret A spinneret is a silk-spinning organ of a spider or the larva of an insect. Some adult insects also have spinnerets, such as those borne on the forelegs of Embioptera. Spinnerets are usually on the underside of a spider's opisthosoma, and a ...

and the cellulose is regenerated in hardening baths that remove the copper and ammonia and neutralize the caustic soda. Cuprammonium rayon is usually made in fine filaments that are used in lightweight summer dresses and blouses, sometimes in combination with

cotton Cotton is a soft, fluffy staple fiber that grows in a boll, or protective case, around the seeds of the cotton plants of the genus '' Gossypium'' in the mallow family Malvaceae. The fiber is almost pure cellulose, and can contain minor pe ...

to make textured fabrics with slubbed, uneven surfaces. The fabric is commonly known by the trade name "Bemberg", owned by the J.P. Bemberg company. The fabric may also be known as "cupro" or "cupra". It is also known as "ammonia silk" on Chinese fashion retail websites.

History

Cuprammonium rayon was invented in 1890. Swiss

chemist A chemist (from Greek ''chēm(ía)'' alchemy; replacing ''chymist'' from Medieval Latin ''alchemist'') is a scientist trained in the study of chemistry. Chemists study the composition of matter and its properties. Chemists carefully describe t ...

Matthias Eduard Schweizer (1818–1860) discovered that cellulose dissolves in tetraaminecopper dihydroxide.

Max Fremery Max Fremery (29 March 1859 – 1 March 1932) was a German chemist and industrialist. He was one of the founders of the (VGF) in 1899. VGF became a major manufacturer of artificial fibers. Early years (1859–85) Fremery was born in Cologne on 2 ...

and

Johann Urban Johann Urban (or Johannes Urban, 7 June 1863 – 13 November 1940) was an Austrian chemist and industrialist. He was one of the pioneers of the artificial silk industry. Early years Johann Urban was born on 7 June 1863 in Wuchern (now Vuhred) nea ...

developed a method to produce

carbon fiber Carbon fiber-reinforced polymers (American English), carbon-fibre-reinforced polymers (Commonwealth English), carbon-fiber-reinforced plastics, carbon-fiber reinforced-thermoplastic (CFRP, CRP, CFRTP), also known as carbon fiber, carbon compo ...

s for use in light bulbs in 1897 (the factory closed in 1902). Production of cuprammonium rayon for textiles started in 1899 in the

Vereinigte Glanzstoff Fabriken AG Vereinigte Glanzstoff-Fabriken (VGF, United Rayon Factories) was a German manufacturer of artificial fiber founded in 1899 that became one of the leading European producers of rayon. During the first thirty years VGF cooperated closely with the B ...

in Oberbruch near Aachen.''Verinigte Glanstoff Fabriken'' merged with the ''Nederlandse Kunstzijdefabrieken'' in 1929 to form the ''Algemene Kunstzijde Unie'',

AkzoNobel Akzo Nobel N.V., stylized as AkzoNobel, is a Dutch multinational company which creates paints and performance coatings for both industry and consumers worldwide. Headquartered in Amsterdam, the company has activities in more than 80 countries ...

's predecessor. An improvement by

J. P. Bemberg AG J. P. Bemberg was a German rayon manufacturer that produced an unusually fine artificial fiber which became known as Bemberg®. J. P. Bemberg came under the control of Vereinigte Glanzstoff-Fabriken and eventually disappeared after a series of merg ...

in 1904 made the artificial silk a product comparable to real silk.''J. P. Bemberg AG'' was one of the ''

Vereinigte Glanzstoff-Fabriken Vereinigte Glanzstoff-Fabriken (VGF, United Rayon Factories) was a German manufacturer of artificial fiber founded in 1899 that became one of the leading European producers of rayon. During the first thirty years VGF cooperated closely with the B ...

'' which merged into the Dutch based ''Algemene Kunstzijde Unie'' (AKU)--

today.

Properties

* The fibers are very fine * It has a soft,

silk Silk is a natural protein fiber, some forms of which can be woven into textiles. The protein fiber of silk is composed mainly of fibroin and is produced by certain insect larvae to form cocoons. The best-known silk is obtained from the ...

-like handle (i.e., tactile feel) * It has similar properties to cotton. It is different in that the average

degree of polymerization The degree of polymerization, or DP, is the number of monomeric units in a macromolecule or polymer or oligomer molecule. For a homopolymer, there is only one type of monomeric unit and the ''number-average'' degree of polymerization is given b ...

is lower and a larger part of this fiber is occupied by amorphous regions, causing cuprammonium rayon to swell * It burns rapidly and chars at 180°C * On ignition, it leaves behind ash containing copper * It can be used to create fabric that is sheer and lightweight and has desirable draping properties

Production

Cellulose is dissolved in a u(NH₃)₄OH)₂ solution and then regenerates as rayon when extruded into sulfuric acid.

References

Synthetic fibers Cellulose {{fashion-stub