CELLULOSE

Cellulose is an organic compound with the formula (C6H10O5)n, 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 cell walls of green plants, many forms of algae, and the oomycetes. 
Some species of bacteria secrete it to form biofilms.

CAS:    9004-34-6
MF:    (C12H20O10)n
MW:    324.28
EINECS:    232-674-9

Synonyms
AVICEL PH;AVICEL PH 101(R);AVICEL PH 105(R);AVICEL(R);''AVICEL(R)'';AVICEL SF;AVIRIN;HYCIL 101 MICROCRYSTALLINE CELLULOSE

Cellulose is the most abundant organic polymer on Earth.
The cellulose content of cotton fibre is 90%, that of wood is 40–50%, and that of dried hemp is approximately 57%.
Cellulose is used mainly to produce paperboard and paper. 
Smaller quantities are converted into a wide variety of derivative products such as cellophane and rayon. 
Conversion of cellulose from energy crops into biofuels such as cellulosic ethanol is under development as a renewable fuel source. 
Cellulose for industrial use is mainly obtained from wood pulp and cotton.
In addition, cellulose exhibits pronounced susceptibility to direct interactions with certain organic liquids, notably formamide and DMSO, and short-chain amines (methylamine, ethylamine) are among the compounds recognized as highly effective swelling agents.
Some animals, particularly ruminants and termites, can digest cellulose with the help of symbiotic micro-organisms that live in their guts, such as Trichonympha. 
In human nutrition, cellulose is a non-digestible constituent of insoluble dietary fiber, acting as a hydrophilic bulking agent for feces and potentially aiding in defecation.

A natural carbohydrate high polymer (polysaccha- ride) consisting of anhydroglucose units joined by an oxygen linkage to form long molecular chains that are essentially linear. 
Cellulose can be hydrolyzed to glucose. 
The degree of polymerization is from 1000 for wood pulp to 3500 for cotton fiber, giving a molecular weight from 160,000 to 560,000. Cellulose is a colorless solid, d approximately 1.50, insoluble in water and organic solvents. 
Cellulose will swell in sodium hydroxide solution and is soluble in Schweitzer’s reagent. 
Cellulose is the fundamental con- stituent of all vegetable tissues (wood, grass, cotton, etc.) and the most abundant organic material in the world. 
Cotton fibers are almost pure cellulose; wood contains approximately 50%. 
The physical structure of cellulose is unusual in that it is not a single crystal but consists of crystalline areas embedded in amorphous areas. 
Chemical reagents penetrate the latter more easily than the former. 
Cel- lulose is virtually odorless and tasteless and is com- bustible, with an ignition point of approximately 450F. 
In some forms, Cellulose is flammable. For example, railroad shipping regulations require a flammable label on such items as burnt fiber, burnt cotton, wet waste paper, and wet textiles. 
Fires have been known to occur in warehouses in which telephone books were stored. 
These were undoubtedly due to heat buildup in the paper caused by microbial activity and self-sustaining oxidation.

Odorless, white powdery fibers. 
Density 1.5 g cm-3. 
The biopolymer composing the cell wall of vegetable tissues. 
Prepared by treating cotton with an organic solvent to de-wax Cellulose microcrystalline and removing pectic acids by extration with a solution of sodium hydroxide. 
The principal fiber composing the cell wall of vegetable tissues (wood, cotton, flax, grass, etc.). 
Technical uses depend on the strength and flexibility of its fibers. 
Insoluble in water. 
Soluble with chemical degradation in sulfuric aicd, and in concentrated solutions of zinc chloride. 
Soluble in aqueous solutions of cupric ammonium hydroxide (Cu(NH3)4(OH)2).

Cellulose is a complex carbohydrate and a key structural component of the cell walls in green plants, algae, and some fungi.
Cellulose is a polysaccharide composed of linear chains of glucose units linked by β-1,4-glycosidic bonds, which confer rigidity and strength to plant structures. 
Cellulose is insoluble in water and most organic solvents, making it a crucial material in various applications, including paper production, textiles, and as a food additive. 
Cellulose's fibrous nature allows it to provide dietary fiber, promoting digestive health in humans. 
Cellulose can be chemically modified to produce derivatives such as cellulose acetate and carboxymethyl cellulose, which have enhanced solubility and functionality. 
The CAS number 9004-34-6 specifically identifies cellulose in its natural form. 
Due to its abundance and renewability, cellulose is considered an important biopolymer in sustainable materials research and biofuel production, as it can be converted into glucose and subsequently fermented into bioethanol. 
Overall, cellulose is a versatile and environmentally friendly material with significant industrial and biological importance.

History
Cellulose was discovered in 1838 by the French chemist Anselme Payen, who isolated it from plant matter and determined its chemical formula.
Cellulose was used to produce the first successful thermoplastic polymer, celluloid, by Hyatt Manufacturing Company in 1870. 
Production of rayon ("artificial silk") from cellulose began in the 1890s and cellophane was invented in 1912. 
Hermann Staudinger determined the polymer structure of cellulose in 1920. 
The compound was first chemically synthesized (without the use of any biologically derived enzymes) in 1992, by Kobayashi and Shoda.

Cellulose Chemical Properties
Melting point: 76-78 °C(Solv: acetone (67-64-1); chloroform (67-66-3))
bulk density: 70-400kg/m3
density: 1.5 g/cm3 (20℃)
refractive index: n20/D 1.504
Fp: 164 °C
storage temp.: room temp
solubility: Practically insoluble in water, in acetone, in anhydrous ethanol, in toluene, in dilute acids and in a 50 g/L solution of sodium hydroxide
form: powder
color: White or almost white
PH: 5-7.5 (100g/l, H2O, 20℃)(slurry)
Odor: Odorless
biological source: spruce
Optical Rotation: -120 (Cuprammonium hydroxide solution)
Water Solubility: insoluble
Merck: 14,1965
Exposure limits    ACGIH: TWA 10 mg/m3
OSHA: TWA 15 mg/m3; TWA 5 mg/m3
NIOSH: TWA 10 mg/m3; TWA 5 mg/m3; TWA 1 mg/m3
Dielectric constant: 3.2（Ambient）
Stability: Stable. Combustible. Incompatible with strong oxidizing agents.
Cosmetics Ingredients Functions: OPACIFYING
LIGHT STABILIZER
ABSORBENT
BULKING
EMULSION STABILISING
ABRASIVE
ANTICAKING
VISCOSITY CONTROLLING
Cosmetic Ingredient Review (CIR): Microcrystalline cellulose (9004-34-6)
InChI: 1S/C12H22O11/c13-1-3-5(15)6(16)9(19)12(22-3)23-10-4(2-14)21-11(20)8(18)7(10)17/h3-20H,1-2H2/t3,4,5,6,7,8,9,10-,11,12+/m1/s1
InChIKey: UFHFLCQGNIYNRP-UHFFFAOYSA-N
EPA Substance Registry System: Cellulose (9004-34-6)

Microcrystalline cellulose and carboxymethylcellulose sodium occurs as a white or off-white odorless and tasteless hygroscopic powder containing 5–22% sodium carboxymethylcellulose. 
Cellulose is a water-dispersible organic hydrocolloid.
Microcrystalline cellulose is a purified, partially depolymerized cellulose that occurs as a white, odorless, tasteless, crystalline powder composed of porous particles. 
Cellulose is commercially available in different particle sizes and moisture grades that have different properties and applications.

Structure and properties
Cellulose has no taste, is odorless, is hydrophilic with the contact angle of 20–30 degrees, is insoluble in water and most organic solvents, is chiral and is biodegradable. 
Cellulose was shown to melt at 467 °C in pulse tests made by Dauenhauer et al. (2016).
Cellulose can be broken down chemically into its glucose units by treating it with concentrated mineral acids at high temperature.

Cellulose is derived from D-glucose units, which condense through β(1→4)-glycosidic bonds. 
This linkage motif contrasts with that for α(1→4)-glycosidic bonds present in starch and glycogen. 
Cellulose is a straight chain polymer. 
Unlike starch, no coiling or branching occurs and the molecule adopts an extended and rather stiff rod-like conformation, aided by the equatorial conformation of the glucose residues. 
The multiple hydroxyl groups on the glucose from one chain form hydrogen bonds with oxygen atoms on the same or on a neighbour chain, holding the chains firmly together side-by-side and forming microfibrils with high tensile strength. 
This confers tensile strength in cell walls where cellulose microfibrils are meshed into a polysaccharide matrix. 
The high tensile strength of plant stems and of the tree wood also arises from the arrangement of cellulose fibers intimately distributed into the lignin matrix. 
The mechanical role of cellulose fibers in the wood matrix responsible for its strong structural resistance, can somewhat be compared to that of the reinforcement bars in concrete, lignin playing here the role of the hardened cement paste acting as the "glue" in between the cellulose fibres. Mechanical properties of cellulose in primary plant cell wall are correlated with growth and expansion of plant cells.
Live fluorescence microscopy techniques are promising in investigation of the role of cellulose in growing plant cells.

Compared to starch, cellulose is also much more crystalline. 
Whereas starch undergoes a crystalline to amorphous transition when heated beyond 60–70 °C in water (as in cooking), cellulose requires a temperature of 320 °C and pressure of 25 MPa to become amorphous in water.
Several types of cellulose are known. 
These forms are distinguished according to the location of hydrogen bonds between and within strands. 
Natural cellulose is cellulose I, with structures Iα and Iβ. 
Cellulose produced by bacteria and algae is enriched in Iα while cellulose of higher plants consists mainly of Iβ. 
Cellulose in regenerated cellulose fibers is cellulose II. 
The conversion of cellulose I to cellulose II is irreversible, suggesting that cellulose I is metastable and cellulose II is stable. 
With various chemical treatments it is possible to produce the structures cellulose III and cellulose IV.

Many properties of cellulose depend on its chain length or degree of polymerization, the number of glucose units that make up one polymer molecule. 
Cellulose from wood pulp has typical chain lengths between 300 and 1700 units; cotton and other plant fibers as well as bacterial cellulose have chain lengths ranging from 800 to 10,000 units.
Molecules with very small chain length resulting from the breakdown of cellulose are known as cellodextrins; in contrast to long-chain cellulose, cellodextrins are typically soluble in water and organic solvents.
The chemical formula of cellulose is (C6H10O5)n where n is the degree of polymerization and represents the number of glucose groups.
Plant-derived cellulose is usually found in a mixture with hemicellulose, lignin, pectin, and other substances, while bacterial cellulose is quite pure, has a much higher water content and higher tensile strength due to higher chain lengths.: 3384 

Cellulose consists of fibrils with crystalline and amorphous regions.
These cellulose fibrils may be individualized by mechanical treatment of cellulose pulp, often assisted by chemical oxidation or enzymatic treatment, yielding semi-flexible cellulose nanofibrils generally 200 nm to 1 μm in length depending on the treatment intensity. 
Cellulose pulp may also be treated with strong acid to hydrolyze the amorphous fibril regions, thereby producing short rigid cellulose nanocrystals a few 100 nm in length.
These nanocelluloses are of high technological interest due to their self-assembly into cholesteric liquid crystals, production of hydrogels or aerogels, use in nanocomposites with superior thermal and mechanical properties, and use as Pickering stabilizers for emulsions.

Uses    
Wood contains 50–70% cellulose; cotton and other textile fibers of plant origin contain 65–95%; rayon is prepared by dissolving natural cellulose and then precipitating it from solution, with some loss of crystallinity. 
Cellulose is made into cellophane film and is used to form fibers, resins, coatings and gums.
cellulose is a thickener and an emulsifier. 
Cellulose is obtained from plants. cellulose (microcrystalline) is used as an emulsifier in cosmetic creams. 
Cellulose is the chief constituent of plant fiber.
High purity cellulose powders for partition chromatography.
ACCEL-101 is most widely used for direct compression tableting and wet granulation. ACCEL-102 has similar compression properties to ACCEL-101. 
However, Cellulose has larger particle size and therefore, may be of value in improving the flow if fine powders.
Cellulose is a carbohydrate polymer made up of glucose units. 
Cellulose consists of fibrous particles and is used as a fiber source and bulking agent in low-calorie formulations.

Microcrystalline Cellulose is a gum that is the nonfibrous form of cellulose, an alpha-cellulose. 
Cellulose is dispersible in water but not soluble, requiring considerable energy to disperse and hydrate. 
In this form Cellulose is used in dry applications such as tableting, capsules, and shredded cheese where it functions as a non-nutritive filler, binder, flow aid, and anticaking agent. 
By the addition of carboxymethylcellulose to the alpha-cellulose prior to drying, improved functional properties of hydration and dispersion are obtained. 
Cellulose is designed for use in water dispersions, being insoluble in water but dispersing in water to form colloidal sols below 1% and white opaque gels above the 1% usage level. 
Cellulose is used as a heat shock stabilizer and bodying agent in frozen desserts, as an opacifier in low-fat dressings, as a foam stabilizer in whipped toppings, and as an emulsifier in dressings. 
Also termed cellulose gel.

Pharmaceutical Applications    
Microcrystalline cellulose and carboxymethylcellulose sodium is used to produce thixotropic gels suitable as suspending vehicles in pharmaceutical and cosmetic formulations. 
The sodium carboxymethylcellulose aids dispersion and serves as a protective colloid.
Concentrations of less than 1% solids produce fluid dispersions, while concentrations of more than 1.2% solids produce thixotropic gels. 
When properly dispersed, it imparts emulsion stability, opacity and suspension in a variety of products, and is used in nasal sprays, topical sprays and lotions, oral suspensions, emulsions, creams and gels.

Industrial uses
Cellulose is the main constituent of the structureof plants (natural polymer) that, whenextracted, is employed for making paper,plastics, and in many combinations. 
Celluloseis made up of long-chain molecules inwhich the complex unit C6H10O5 is repeatedas many as 2000 times. 
Cellulose consists of glucose molecules with three hydroxyl groups foreach glucose unit.
One of the simplest forms of cellulose usedindustrially is regenerated cellulose, in whichthe chemical composition of the finished productis similar to that of the original cellulose. 
Cellulose is made from wood or cotton pulp digested ina caustic solution. 
Cellophane is a regeneratedcellulose in thin sheets for wrapping and otherspecial uses include windings on wire andcable.

Production Methods    
Microcrystalline cellulose and carboxymethylcellulose sodium is a spray- or bulk-dried blend of microcrystalline cellulose and sodium carboxymethylcellulose. 
Cellulose is prepared by the chemical depolymerization of highly purified wood pulp. 
The original crystalline areas of the pulp fibers are combined with sodium carboxymethylcellulose, which serves as a protective colloid and also facilitates dispersion of the product; Cellulose is then either spray- or bulk-dried.

Production Methods    
Cellulose is manufactured by controlled hydrolysis with dilute mineral acid solutions of α-cellulose, obtained as a pulp from fibrous plant materials. 
Following hydrolysis, the hydrocellulose is purified by filtration and the aqueous slurry is spraydried to form dry, porous particles of a broad size distribution.

Reactivity Profile    
Cellulose microcrystalline is combustible. 
Incompatible with strong oxidizing agents including bromine pentafluoride, sodium nitrate, fluorine, perchlorates, perchloric acid, sodium chlorate, magnesium perchlorate, F2, zinc permanganate, sodium nitrite, sodium nitrate, sodium peroxide. 
Nitration with a mixture of nitric and sulfuric acids produces Cellulose microcrystalline nitrates (celluloid pyroxylin, soluble pyroxyline, guncotton) which are flammable or explosive.