Cellulose acetate
In biochemistry, cellulose acetate refers to any acetate ester of cellulose, usually cellulose diacetate. It was first prepared in 1865. A bioplastic, cellulose acetate is used as a film base in photography, as a component in some coatings, and as a frame material for eyeglasses; it is also used as a synthetic fiber in the manufacture of cigarette filters and playing cards. In photographic film, cellulose acetate film replaced nitrate film in the 1950s, being far less flammable and cheaper to produce.
Water-soluble cellulose acetate has been used as a dietary fiber, in relation with weight loss and Akkermansia muciniphila.
History
In 1865, French chemist Paul Schützenberger discovered that cellulose reacts with acetic anhydride to form cellulose acetate. The German chemists Arthur Eichengrün and Theodore Becker invented the first soluble forms of cellulose acetate in 1903.In 1904, Camille Dreyfus and his younger brother Henri performed chemical research and development on cellulose acetate in a shed in their father's garden in Basel, Switzerland, which was then a center of the dye industry. For five years, the Dreyfus brothers studied and experimented in a systematic manner in Switzerland and France. By 1910, they were producing film for the motion picture industry, and a small but constantly growing amount of acetate lacquer, called "dope", was sold to the expanding aircraft industry to coat the fabric covering wings and fuselage.
In 1913, after some twenty thousand separate experiments, they produced excellent laboratory samples of continuous filament yarn, something that had eluded the cellulose acetate industry to this time. Unfortunately, the outbreak of World War I postponed commercial development of this process.
In November 1914, the British Government invited Camille Dreyfus to come to England to manufacture acetate dope, and the "British Cellulose and Chemical Manufacturing Co" was set up. In 1917, after the United States had entered the war, the U.S. War Department invited Dreyfus to establish a similar factory in the U.S. Both operations were run successfully throughout the war.
After the war, attention returned to the production of acetate fibers. The first yarn was of fair quality, but sales resistance was heavy, and silk associates worked zealously to discredit acetate and discourage its use. However, the thermoplastic nature of acetate made it an excellent fiber for moiré because the pattern was permanent and did not wash away. The same characteristic also made permanent pleating a commercial fact for the first time, and gave great style impetus to the whole dress industry.
The mixing of silk and acetate in fabrics was accomplished at the beginning, and almost at once cotton was also blended, thus making possible low-cost fabrics by means of a fiber which then was cheaper than silk or acetate. Today, acetate is blended with silk, cotton, wool, nylon, etc. to give fabrics excellent wrinkle recovery, good heft, handle, draping quality, quick drying, proper dimensional stability, cross-dye pattern potential, at a very competitive price.
Types
There are types of cellulose acetate with mixed‐ester derivatives.- Cellulose Acetate Butyrate
- Cellulose Acetate Propionate
Chemical and physical properties
Use as a fiber
Cellulose acetate fiber, one of the earliest synthetic fibers, is based on cotton or tree pulp cellulose. These "cellulosic fibers" have been replaced in many applications by cheaper petro-based fibers in recent decades.Trade names for acetate include Acele, Avisco, Celanese, Chromspun, and Estron.
Acetate shares many similarities with rayon, and was formerly considered as the same textile. Acetate differs from rayon in the employment of acetic acid in production. The two fabrics are now required to be listed distinctly on garment labels.
Rayon resists heat while acetate is prone to melting. Acetate must be laundered with care either by hand-washing or dry cleaning.
The breathable nature of the fabric suits it for use as a lining. Acetate fabric is used frequently in wedding gowns and other bridal attire. Its lustrous sheen and smooth, satiny texture make it a good alternative to silk.
Properties
Acetate is a low cost, manufactured fiber, which has good draping qualities. Acetate is used in fabrics such as satins, brocades, knit fabrics, and taffetas to accentuate luster, body, drape, and beauty.- Hand: soft, smooth, dry, crisp, resilient
- Comfort: breathes, wicks, dries quickly, no static cling
- Drape: linings move with the body linings conform to the garment
- Color: deep brilliant shades with atmospheric dyeing meet colorfastness requirements
- Luster: light reflection creates a signature appearance
- Performance: colorfast to perspiration staining, colorfast to dry cleaning, air and vapor permeable
- Tenacity: weak fiber with breaking tenacity of 1.2 to 1.4 g/d; rapidly loses strength when wet
- Abrasion: poor resistance
- Heat retention: poor thermal retention; no allergenic potential
- Dyeability: cross-dying method where yarns of one fiber and those of another fiber are woven into a fabric in a desired pattern; solution-dying method provides excellent color fastness under the effects of sunlight, perspiration, air contaminants and washing
Characteristics
- cellulosic and thermoplastic
- selective absorption and removal of low levels of certain organic chemicals
- easily bonded with plasticizers, heat, and pressure
- acetate is soluble in many common solvents and can be modified to be soluble in alternative solvents, including water
- hydrophilic: acetate wets easily, with good liquid transport and excellent absorption; in textile applications, it provides comfort and absorbency, but also loses strength when wet
- acetate fibers are hypoallergenic
- high surface area
- made from wood pulp, a renewable resource
- can be composted or incinerated
- can be dyed, however special dyes and pigments are required since acetate does not accept dyes ordinarily used for cotton and rayon
- resistant to mold and mildew
- easily weakened by strong alkaline solutions and strong oxidizing agents
- can usually be washed or dry cleaned; generally does not shrink
Confusion with ''cellulose triacetate''
Film
, made from cellulose diacetate and later cellulose triacetate, was introduced in 1934 as a replacement for the cellulose nitrate film stock that had previously been standard. When exposed to heat or moisture, acids in the film base begin to deteriorate to an unusable state, releasing acetic acid with a characteristic vinegary smell, causing the process to be known as "vinegar syndrome". Acetate film stock is still used in some applications, such as camera negative for motion pictures. Since the 1980s, polyester film stock has become more commonplace, particularly for archival applications. Acetate film was also used as the base for magnetic tape, prior to the advent of polyester film.Magnetic tape
Cellulose acetate magnetic tape was introduced by IBM in 1952 for use on their IBM 726 tape drive in the IBM 701 computer. It was much lighter and easier to handle than the metal tape introduced by UNIVAC in 1951 for use on their UNISERVO tape drive in the UNIVAC I computer. In 1956, cellulose acetate magnetic tape was replaced by the more stable PET film magnetic tape for use on their IBM 727 tape drive.Other products
Due to its material properties that have it usable as a fabric, fiber or plastic, cellulose acetate is used to manufacture multiple products; for example, in the world of fabrics, acetate is utilized to make dresses, blouses, party attire, award ribbons, buttons, home furnishings, draperies and upholstery, among other uses. Plastic eyeglass frames are also frequently manufactured of acetates, as are absorbent products like diapers, ink reservoirs and cigarette filters. LEGO bricks were originally manufactured of acetate from 1949 to 1963, as are some brands of high-end playing cards, such as Kem and Modiano Platinum. Lastly, overhead-projection transparencies are frequently produced on acetate sheets.Production
The Federal Trade Commission definition for acetate fiber is: "A manufactured fiber in which the fiber-forming substance is cellulose acetate. Where not less than 92 percent of the hydroxyl groups are acetylated, the term triacetate may be used as a generic description of the fiber."Acetate is derived from cellulose by initially deconstructing wood pulp into a purified fluffy white cellulose. To manufacture a good product, special qualities of pulps, such as dissolving pulps, are used. The uneven reactivity of cellulose presents a common problem affecting the quality of the cellulose acetate product. The cellulose is reacted with acetic acid and acetic anhydride in the presence of sulfuric acid. It is subjected to a controlled, partial hydrolysis to remove the sulfate and a sufficient number of acetate groups to give the product the desired properties. The anhydroglucose unit is the fundamental repeating structure of cellulose and has three hydroxyl groups which can react to form acetate esters. The most common form of cellulose acetate fiber has an acetate group on approximately two of every three hydroxyls. This cellulose diacetate is known as secondary acetate, or simply as "acetate".
After it is formed, cellulose acetate is dissolved in acetone, forming a viscous solution for extrusion through spinnerets. As the filaments emerge, the solvent is evaporated in warm air via dry spinning, producing fine cellulose acetate fibers.
The first U.S. commercial acetate fiber was produced by the Celanese Corporation in 1924. Current U.S. acetate fiber producers are Celanese, and Eastman Chemical Company.