Methylcellulose
Encyclopedia
Methyl cellulose is a chemical compound
derived from cellulose
. It is a hydrophilic
white powder in pure form and dissolves in cold (but not in hot) water, forming a clear viscous solution or gel. It is sold under a variety of trade names and is used as a thickener and emulsifier in various food and cosmetic products, and also as a treatment of constipation
. Like cellulose, it is not digestible, not toxic, and not an allergen
.
residues (-OH functional groups) are replaced by methoxide
(-OCH3 groups).
Different kinds of methyl cellulose can be prepared depending on the number of hydroxyl groups substituted. Cellulose is a polymer
consisting of numerous linked glucose
molecules, each of which exposes three hydroxyl groups. The Degree of Substitution (DS) of a given form of methyl cellulose is defined as the average number of substituted hydroxyl groups per glucose. The theoretical maximum is thus a DS of 3.0, however more typical values are 1.3–2.6.
Different methyl cellulose preparations can also differ in the average length of their polymer backbones.
(LCST) between 40°C and 50°C. At temperatures below the LCST, it is readily soluble
in water; above the LCST, it is not soluble, which has a paradoxical effect that heating a saturated solution of methyl cellulose will turn it solid, because methyl cellulose will precipitate
out. The temperature at which this occurs depends on DS-value, with higher DS-values giving lower solubility and lower precipitation temperatures because the polar hydroxyl groups are masked.
Preparing a solution of methyl cellulose with cold water is difficult however: as the powder comes into contact with water, a gluey layer forms around it, and the inside remains dry. A better way is to first mix the powder with hot water, so that the methyl cellulose particles are well dispersed in the water, and cool down this dispersion
while stirring, leading to the dissolution of those particles.
s, tooth pastes and liquid soaps, to generate their characteristic thick consistency. This is also done for foods, for example ice cream
or croquette
. Methyl cellulose is also an important emulsifier, preventing the separation of two mixed liquids.
The E number
of methyl cellulose as food additive is E461.
Methyl cellulose (AKS Methocel produced by Dow Chemical) is also used as paint rheological modifier to prevent paint sagging problem.
, producing a softer and bulkier stool. It is used to treat constipation
, diverticulosis
, hemorrhoids and irritable bowel syndrome
. It should be taken with sufficient amounts of fluid to prevent dehydration
.
Because it absorbs water and potentially toxic materials and increases viscosity, it can also be used to treat diarrhea
.
A well-known trade name of methyl cellulose when used as a drug is Citrucel by GlaxoSmithKline
, but generic versions
are also widely available.
personal lubricant; it is the main ingredient in K-Y Jelly
.
Sicca). Dry eyes are common in the elderly and is often associated with rheumatoid arthritis
. The lacrimal gland and the accessory conjucntival glands produce fewer tears
. Methyl cellulose may be used as a tear substitute.
or saliva
if the natural production of these fluids is disturbed.
.
, has the unique property of setting when hot and melting
when cold. This technique is currently being developed at the University of Nottingham
.
dry mixes to improve the mortar's properties such as workability, open and adjustment time, water retention, viscosity, adhesion to surfaces etc. Construction grade methyl cellulose is to not to be identified with food and pharmaceutical grade methyl cellulose and hydroxypropyl methyl cellulose, since it may be cross-linked with glyoxal
for easy dispersion in water.
The construction materials can be cement based or gypsum based. Notable examples of dry mixture mortars which utilize methyl cellulose include: tile adhesives, EIFS, insulating plasters, hand-trowed and machine sprayed plaster, stucco, self-leveling flooring, extruded cement panels, skim coats, joint & crack fillers, and tile grouts. Typical usage is about 0.2% ~ 0.5% of total dry powder weight for dry mixture
Derivatives of methyl cellulose, which improve upon the performance characteristics, include hydroxypropyl methyl cellulose
(HPMC) and hydroxyethyl methyl cellulose
(HEMC). These derivatives typically improve the characteristics such as water retention, vertical surface slip-resistance, open time, etc.
Manufacturers of such construction grade methyl cellulose include SE Tylose, Dowwolff, Shin-Etsu, Samsung Fine Chemicals, Hercules Aqualon, and various smaller manufacturers.
which can be washed away with water. This may be used in the fixation of delicate pieces of art as well as in book conservation to loosen and clean off old glue from spines and bookboards.
Methyl cellulose is the main ingredient in many wallpaper paste
s. It is also used as a binder in pastel crayons
and also as a binder in medications.
in the production of papers and textiles as it protects the fibers from absorbing water or oil.
to study viral
replication. It is dissolved in the same nutrient containing medium
in which cells are normally grown. A single layer of cells are grown on a flat surface, then infected with a virus for a short time. The strength of the viral sample used will determine how many cells get infected during this time. The thick methyl cellulose medium is then added on top of the cells in place of normal liquid medium. As the viruses replicate in the infected cells, they are able to spread between cells whose membrances touch each other, but are trapped when they enter the methyl cellulose. Only cells closely neighboring an infected cell will become infected and die. This leaves small regions of dead cells called plaques
in a larger background of living uninfected cells. The number of plaques formed is determined by the strength of the original sample.
to control electroosmotic flow for improved separations.
wherever vile slimes must be simulated. In the film Ghostbusters
, for example, the gooey substance the supernatural entities used to “slime” the Ghostbusters was mostly a thick water solution of methyl cellulose. The Aliens
ooze and drip a great deal of methyl cellulose -- especially the queen.
Methyl cellulose has been used to safely simulate molten materials, as well. In several of the Terminator
films, it was back-lit with colored gels and films to reproduce the heated glow of iron in the large pouring ladles used to transport the metal from the smelting ovens to the various molds and forms. Methyl cellulose was also a stand-in for the lava flows on the volcanic surface of Mustafar
, in Star Wars Episode III :Revenge of the Sith.
Chemical compound
A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...
derived from cellulose
Cellulose
Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to over ten thousand β linked D-glucose units....
. It is a hydrophilic
Hydrophile
A hydrophile, from the Greek "water" and φιλια "love," is a molecule or other molecular entity that is attracted to, and tends to be dissolved by water. A hydrophilic molecule or portion of a molecule is one that has a tendency to interact with or be dissolved by, water and other polar substances...
white powder in pure form and dissolves in cold (but not in hot) water, forming a clear viscous solution or gel. It is sold under a variety of trade names and is used as a thickener and emulsifier in various food and cosmetic products, and also as a treatment of constipation
Constipation
Constipation refers to bowel movements that are infrequent or hard to pass. Constipation is a common cause of painful defecation...
. Like cellulose, it is not digestible, not toxic, and not an allergen
Allergen
An allergen is any substance that can cause an allergy. In technical terms, an allergen is a non-parasitic antigen capable of stimulating a type-I hypersensitivity reaction in atopic individuals....
.
Chemistry
Methyl cellulose does not occur naturally and is synthetically produced by heating cellulose with caustic solution (e.g. a solution of sodium hydroxide) and treating it with methyl chloride. In the substitution reaction that follows, the hydroxylHydroxyl
A hydroxyl is a chemical group containing an oxygen atom covalently bonded with a hydrogen atom. In inorganic chemistry, the hydroxyl group is known as the hydroxide ion, and scientists and reference works generally use these different terms though they refer to the same chemical structure in...
residues (-OH functional groups) are replaced by methoxide
Methoxide
Methoxides are organic salts and the simplest alkoxides. Sodium methoxide and potassium hydroxide have widespread use, though other variants such as lithium hydroxide, rubidium methoxide, caesium methoxide, and francium methoxide exist as well.- Methoxide ion :In organic chemistry, the methoxide...
(-OCH3 groups).
Different kinds of methyl cellulose can be prepared depending on the number of hydroxyl groups substituted. Cellulose is a polymer
Polymer
A polymer is a large molecule composed of repeating structural units. These subunits are typically connected by covalent chemical bonds...
consisting of numerous linked glucose
Glucose
Glucose is a simple sugar and an important carbohydrate in biology. Cells use it as the primary source of energy and a metabolic intermediate...
molecules, each of which exposes three hydroxyl groups. The Degree of Substitution (DS) of a given form of methyl cellulose is defined as the average number of substituted hydroxyl groups per glucose. The theoretical maximum is thus a DS of 3.0, however more typical values are 1.3–2.6.
Different methyl cellulose preparations can also differ in the average length of their polymer backbones.
Solubility and temperature
Methyl cellulose has a lower critical solution temperatureLower critical solution temperature
The lower critical solution temperature or lower consolute temperature is the critical temperature below which the components of a mixture are miscible for all compositions...
(LCST) between 40°C and 50°C. At temperatures below the LCST, it is readily soluble
Solubility
Solubility is the property of a solid, liquid, or gaseous chemical substance called solute to dissolve in a solid, liquid, or gaseous solvent to form a homogeneous solution of the solute in the solvent. The solubility of a substance fundamentally depends on the used solvent as well as on...
in water; above the LCST, it is not soluble, which has a paradoxical effect that heating a saturated solution of methyl cellulose will turn it solid, because methyl cellulose will precipitate
Precipitation (chemistry)
Precipitation is the formation of a solid in a solution or inside anothersolid during a chemical reaction or by diffusion in a solid. When the reaction occurs in a liquid, the solid formed is called the precipitate, or when compacted by a centrifuge, a pellet. The liquid remaining above the solid...
out. The temperature at which this occurs depends on DS-value, with higher DS-values giving lower solubility and lower precipitation temperatures because the polar hydroxyl groups are masked.
Preparing a solution of methyl cellulose with cold water is difficult however: as the powder comes into contact with water, a gluey layer forms around it, and the inside remains dry. A better way is to first mix the powder with hot water, so that the methyl cellulose particles are well dispersed in the water, and cool down this dispersion
Dispersion
Dispersion may refer to:In physics:*The dependence of wave velocity on frequency or wavelength:**Dispersion , for light waves**Dispersion **Acoustic dispersion, for sound waves...
while stirring, leading to the dissolution of those particles.
Uses
Methyl cellulose has an extremely wide range of uses, of which several are described below.Thickener and emulsifier
Methyl cellulose is often added to hair shampooShampoo
Shampoo is a hair care product used for the removal of oils, dirt, skin particles, dandruff, environmental pollutants and other contaminant particles that gradually build up in hair...
s, tooth pastes and liquid soaps, to generate their characteristic thick consistency. This is also done for foods, for example ice cream
Ice cream
Ice cream is a frozen dessert usually made from dairy products, such as milk and cream, and often combined with fruits or other ingredients and flavours. Most varieties contain sugar, although some are made with other sweeteners...
or croquette
Croquette
A croquette is a small fried food roll containing, usually as main ingredients, mashed potatoes, and/or ground meat , shellfish, fish, vegetables, and soaked white bread, egg, onion, spices and herbs, wine, milk, beer or any of the combination thereof, sometimes with a filling, often encased in...
. Methyl cellulose is also an important emulsifier, preventing the separation of two mixed liquids.
The E number
E number
E numbers are number codes for food additives that have been assessed for use within the European Union . They are commonly found on food labels throughout the European Union. Safety assessment and approval are the responsibility of the European Food Safety Authority...
of methyl cellulose as food additive is E461.
Methyl cellulose (AKS Methocel produced by Dow Chemical) is also used as paint rheological modifier to prevent paint sagging problem.
Treatment of constipation
When eaten, methyl cellulose is not absorbed by the intestines but passes through the digestive tract undisturbed. It attracts large amounts of water into the colonColon (anatomy)
The colon is the last part of the digestive system in most vertebrates; it extracts water and salt from solid wastes before they are eliminated from the body, and is the site in which flora-aided fermentation of unabsorbed material occurs. Unlike the small intestine, the colon does not play a...
, producing a softer and bulkier stool. It is used to treat constipation
Constipation
Constipation refers to bowel movements that are infrequent or hard to pass. Constipation is a common cause of painful defecation...
, diverticulosis
Diverticulosis
Diverticulosis also known as "diverticular disease" is the condition of having diverticula in the colon, which are outpocketings of the colonic mucosa and submucosa through weaknesses of muscle layers in the colon wall. These are more common in the sigmoid colon, which is a common place for...
, hemorrhoids and irritable bowel syndrome
Irritable bowel syndrome
Irritable bowel syndrome is a diagnosis of exclusion. It is a functional bowel disorder characterized by chronic abdominal pain, discomfort, bloating, and alteration of bowel habits in the absence of any detectable organic cause. In some cases, the symptoms are relieved by bowel movements...
. It should be taken with sufficient amounts of fluid to prevent dehydration
Dehydration
In physiology and medicine, dehydration is defined as the excessive loss of body fluid. It is literally the removal of water from an object; however, in physiological terms, it entails a deficiency of fluid within an organism...
.
Because it absorbs water and potentially toxic materials and increases viscosity, it can also be used to treat diarrhea
Diarrhea
Diarrhea , also spelled diarrhoea, is the condition of having three or more loose or liquid bowel movements per day. It is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. The loss of fluids through diarrhea can cause dehydration and...
.
A well-known trade name of methyl cellulose when used as a drug is Citrucel by GlaxoSmithKline
GlaxoSmithKline
GlaxoSmithKline plc is a global pharmaceutical, biologics, vaccines and consumer healthcare company headquartered in London, United Kingdom...
, but generic versions
Generic drug
A generic drug is a drug defined as "a drug product that is comparable to brand/reference listed drug product in dosage form, strength, route of administration, quality and performance characteristics, and intended use." It has also been defined as a term referring to any drug marketed under its...
are also widely available.
Lubricant
Methyl cellulose is used as a variable viscosityViscosity
Viscosity is a measure of the resistance of a fluid which is being deformed by either shear or tensile stress. In everyday terms , viscosity is "thickness" or "internal friction". Thus, water is "thin", having a lower viscosity, while honey is "thick", having a higher viscosity...
personal lubricant; it is the main ingredient in K-Y Jelly
K-Y Jelly
K-Y Jelly is a water-based, water-soluble personal lubricant produced by Johnson & Johnson. According to the company, "The origins of the brand name 'K-Y' are unknown...
.
Clinical
The lubricating property of methyl cellulose is of particular benefit in the treatment of dry eyes (KeratoconjunctivitisKeratoconjunctivitis
Keratoconjunctivitis is inflammation of the cornea and conjunctiva.When only the cornea is inflamed, it is called keratitis; when only the conjunctiva is inflamed, it is called conjunctivitis....
Sicca). Dry eyes are common in the elderly and is often associated with rheumatoid arthritis
Rheumatoid arthritis
Rheumatoid arthritis is a chronic, systemic inflammatory disorder that may affect many tissues and organs, but principally attacks synovial joints. The process produces an inflammatory response of the synovium secondary to hyperplasia of synovial cells, excess synovial fluid, and the development...
. The lacrimal gland and the accessory conjucntival glands produce fewer tears
Tears
Tears are secretions that clean and lubricate the eyes. Lacrimation or lachrymation is the production or shedding of tears....
. Methyl cellulose may be used as a tear substitute.
Artificial tears and saliva
Solutions containing methyl cellulose or similar cellulose derivatives are used as substitute for tearsTears
Tears are secretions that clean and lubricate the eyes. Lacrimation or lachrymation is the production or shedding of tears....
or saliva
Saliva
Saliva , referred to in various contexts as spit, spittle, drivel, drool, or slobber, is the watery substance produced in the mouths of humans and most other animals. Saliva is a component of oral fluid. In mammals, saliva is produced in and secreted from the three pairs of major salivary glands,...
if the natural production of these fluids is disturbed.
Nutritional supplement capsules
Methyl cellulose is used in the manufacture of capsules in nutritional supplements, its edible and nontoxic properties provide a vegetarian alternative to the use of gelatinGelatin
Gelatin is a translucent, colorless, brittle , flavorless solid substance, derived from the collagen inside animals' skin and bones. It is commonly used as a gelling agent in food, pharmaceuticals, photography, and cosmetic manufacturing. Substances containing gelatin or functioning in a similar...
.
Advanced cookery
Methyl cellulose, as a gelGel
A gel is a solid, jelly-like material that can have properties ranging from soft and weak to hard and tough. Gels are defined as a substantially dilute cross-linked system, which exhibits no flow when in the steady-state...
, has the unique property of setting when hot and melting
Melting
Melting, or fusion, is a physical process that results in the phase change of a substance from a solid to a liquid. The internal energy of a substance is increased, typically by the application of heat or pressure, resulting in a rise of its temperature to the melting point, at which the rigid...
when cold. This technique is currently being developed at the University of Nottingham
University of Nottingham
The University of Nottingham is a public research university based in Nottingham, United Kingdom, with further campuses in Ningbo, China and Kuala Lumpur, Malaysia...
.
Construction materials
Methyl cellulose finds a major application as a performance additive in construction materials. It is added to mortarMortar (masonry)
Mortar is a workable paste used to bind construction blocks together and fill the gaps between them. The blocks may be stone, brick, cinder blocks, etc. Mortar becomes hard when it sets, resulting in a rigid aggregate structure. Modern mortars are typically made from a mixture of sand, a binder...
dry mixes to improve the mortar's properties such as workability, open and adjustment time, water retention, viscosity, adhesion to surfaces etc. Construction grade methyl cellulose is to not to be identified with food and pharmaceutical grade methyl cellulose and hydroxypropyl methyl cellulose, since it may be cross-linked with glyoxal
Glyoxal
Glyoxal is an organic compound with the formula OCHCHO. This yellow colored liquid is the smallest dialdehyde . Its tautomer acetylenediol is unstable.-Production:...
for easy dispersion in water.
The construction materials can be cement based or gypsum based. Notable examples of dry mixture mortars which utilize methyl cellulose include: tile adhesives, EIFS, insulating plasters, hand-trowed and machine sprayed plaster, stucco, self-leveling flooring, extruded cement panels, skim coats, joint & crack fillers, and tile grouts. Typical usage is about 0.2% ~ 0.5% of total dry powder weight for dry mixture
Derivatives of methyl cellulose, which improve upon the performance characteristics, include hydroxypropyl methyl cellulose
Hypromellose
Hypromellose , short for hydroxypropyl methylcellulose , is a semisynthetic, inert, viscoelastic polymer used as an ophthalmic lubricant, as well as an excipient and controlled-delivery component in oral medicaments, found in a variety of commercial products.As a food additive, hypromellose is an...
(HPMC) and hydroxyethyl methyl cellulose
Hydroxyethyl methyl cellulose
Hydroxyethyl methyl cellulose is a gelling and thickening agent derived from cellulose....
(HEMC). These derivatives typically improve the characteristics such as water retention, vertical surface slip-resistance, open time, etc.
Manufacturers of such construction grade methyl cellulose include SE Tylose, Dowwolff, Shin-Etsu, Samsung Fine Chemicals, Hercules Aqualon, and various smaller manufacturers.
Glue and binder
Methyl cellulose can be employed as a mild glueGlue
This is a list of various types of glue. Historically, the term "glue" only referred to protein colloids prepared from animal flesh. The meaning has been extended to refer to any fluid adhesive....
which can be washed away with water. This may be used in the fixation of delicate pieces of art as well as in book conservation to loosen and clean off old glue from spines and bookboards.
Methyl cellulose is the main ingredient in many wallpaper paste
Wallpaper paste
Wallpaper adhesive or wallpaper paste is a specific adhesive, based on modified starch or methylcellulose, used to fix wallpaper to walls.Wallpaper pastes have a typical shear thinning viscosity and a high wet adhesive tack...
s. It is also used as a binder in pastel crayons
Pastel
Pastel is an art medium in the form of a stick, consisting of pure powdered pigment and a binder. The pigments used in pastels are the same as those used to produce all colored art media, including oil paints; the binder is of a neutral hue and low saturation....
and also as a binder in medications.
Paper and textile sizing
Methyl cellulose is used as sizingSizing
Sizing or size is any one of numerous specific substances that is applied to or incorporated in other material, especially papers and textiles, to act as a protecting filler or glaze....
in the production of papers and textiles as it protects the fibers from absorbing water or oil.
Cell culture/virology
Methyl cellulose is also used in cell cultureCell culture
Cell culture is the complex process by which cells are grown under controlled conditions. In practice, the term "cell culture" has come to refer to the culturing of cells derived from singlecellular eukaryotes, especially animal cells. However, there are also cultures of plants, fungi and microbes,...
to study viral
Virus
A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...
replication. It is dissolved in the same nutrient containing medium
Growth medium
A growth medium or culture medium is a liquid or gel designed to support the growth of microorganisms or cells, or small plants like the moss Physcomitrella patens.There are different types of media for growing different types of cells....
in which cells are normally grown. A single layer of cells are grown on a flat surface, then infected with a virus for a short time. The strength of the viral sample used will determine how many cells get infected during this time. The thick methyl cellulose medium is then added on top of the cells in place of normal liquid medium. As the viruses replicate in the infected cells, they are able to spread between cells whose membrances touch each other, but are trapped when they enter the methyl cellulose. Only cells closely neighboring an infected cell will become infected and die. This leaves small regions of dead cells called plaques
Viral plaque
A viral plaque is a visible structure formed within a cell culture, such as bacterial cultures within some nutrient medium . The bacteriophage viruses replicate and spread, thus generating regions of cell destructions known as plaques....
in a larger background of living uninfected cells. The number of plaques formed is determined by the strength of the original sample.
Bacterial motility inhibitor
Aqueous methyl cellulose solutions have been used to slow bacterial cell motility for closer inspection. Changing the amount of methyl cellulose in solution allows one to adjust the solution's viscosity.Stem cell differentiation
Methyl cellulose is used in the most common approaches to quantify multiple or single lineage-committed hematopoietic progenitors, called colony-forming cells (CFCs) or colony-forming units (CFUs), in combination with culture supplements that promote their proliferation and differentiation, and allow the clonal progeny of a single progenitor cell to stay together and thus form a colony of more mature cells. MethoCult and ColonyGEL are examples of such methylcellulose-based media.Chemistry
Methylcellulose is used as a buffer additive in capillary electrophoresisCapillary electrophoresis
Capillary electrophoresis , also known as capillary zone electrophoresis , can be used to separate ionic species by their charge and frictional forces and hydrodynamic radius. In traditional electrophoresis, electrically charged analytes move in a conductive liquid medium under the influence of an...
to control electroosmotic flow for improved separations.
Special effects
The slimy, gooey appearance of an appropriate preparation of methyl cellulose with water, in addition to its nontoxic, nonallergenic, and edible properties, makes it popular for use in special effects for motion pictures and televisionTelevision
Television is a telecommunication medium for transmitting and receiving moving images that can be monochrome or colored, with accompanying sound...
wherever vile slimes must be simulated. In the film Ghostbusters
Ghostbusters
Ghostbusters is a 1984 American science fiction comedy film directed by Ivan Reitman and written by Dan Aykroyd and Harold Ramis. The film stars Bill Murray, Dan Aykroyd, Sigourney Weaver, Harold Ramis, and Rick Moranis and follows three eccentric parapsychologists in New York City, who start a...
, for example, the gooey substance the supernatural entities used to “slime” the Ghostbusters was mostly a thick water solution of methyl cellulose. The Aliens
Aliens (film)
Aliens is a 1986 science fiction action film directed by James Cameron and starring Sigourney Weaver, Carrie Henn, Michael Biehn, Lance Henriksen, William Hope, and Bill Paxton...
ooze and drip a great deal of methyl cellulose -- especially the queen.
Methyl cellulose has been used to safely simulate molten materials, as well. In several of the Terminator
Terminator
-Science:*Terminator , the line between the day and night sides of a planetary body*Terminator , the end of a gene for transcription-Technology:*Terminator , a resistor at the end of a transmission line to prevent signal reflection...
films, it was back-lit with colored gels and films to reproduce the heated glow of iron in the large pouring ladles used to transport the metal from the smelting ovens to the various molds and forms. Methyl cellulose was also a stand-in for the lava flows on the volcanic surface of Mustafar
Mustafar
Mustafar is a fictional planet in the Star Wars universe. It is depicted in Star Wars Episode III: Revenge of the Sith.The planet is covered by hundreds of volcanic caldera, most of which are in a state of constant eruption...
, in Star Wars Episode III :Revenge of the Sith.