METHYL CELLULOSE

Methyl cellulose (or methylcellulose) 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.

USES

Thickener and emulsifier

Methyl cellulose is often added to hair shampoos, 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 (AKA Methocel produced by Dow Chemical or Mecellose produced by Samsung Fine Chemicals) 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 colon, 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.


Lubricant

Methyl cellulose is used as a variable viscosity personal lubricant; it is the main ingredient in K-Y Jelly.


Clinical

The lubricating property of methyl cellulose is of particular benefit in the treatment of dry eyes (Keratoconjunctivitis Sicca).[1] Dry eyes are common in the elderly and is often associated with rheumatoid arthritis. The lacrimal gland and the accessory conjunctival glands produce fewer 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 tears or saliva 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 gelatin.


Construction materials

Methyl cellulose finds a major application as a performance additive in construction materials. It is added to mortar 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.

Glue and binder

Methyl cellulose can be employed as a mild glue 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 pastes. It is also used as a binder in pastel crayons and also as a binder in medications.


Paper and textile sizing

Methyl cellulose is used as sizing in the production of papers and textiles as it protects the fibers from absorbing water or oil.


SOURCE : http://en.wikipedia.org/wiki/Methyl_cellulose