Carboxymethyl cellulose

Cellulose derivative grafted with carboxymethyl groups
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Carboxymethyl cellulose
Names
Other names
Carboxymethylcellulose; carmellose; E466
Identifiers
CAS Number
  • 9004-32-4 checkY
ChEBI
  • CHEBI:85146 ☒N
ChEMBL
  • ChEMBL1909054 ☒N
ChemSpider
  • none
ECHA InfoCard 100.120.377 Edit this at Wikidata
E number E466 (thickeners, ...)
UNII
  • 05JZI7B19X ☒N
CompTox Dashboard (EPA)
  • DTXSID7040441 Edit this at Wikidata
Properties
Chemical formula
variable
Molar mass variable
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)
Infobox references
Chemical compound

Carboxymethyl cellulose (CMC) or cellulose gum[1] is a cellulose derivative with carboxymethyl groups (-CH2-COOH) bound to some of the hydroxyl groups of the glucopyranose monomers that make up the cellulose backbone. It is often used in its sodium salt form, sodium carboxymethyl cellulose. It used to be marketed under the name Tylose, a registered trademark of SE Tylose.[2]

Preparation

Carboxymethyl cellulose is synthesized by the alkali-catalyzed reaction of cellulose with chloroacetic acid.[3] The polar (organic acid) carboxyl groups render the cellulose soluble and chemically reactive.[4] Fabrics made of cellulose–e.g., cotton or viscose rayon—may also be converted into CMC.[5]

Following the initial reaction, the resultant mixture produces approximately 60% CMC and 40% salts (sodium chloride and sodium glycolate). This product, called technical CMC, is used in detergents.[citation needed] An additional purification process is used to remove salts to produce pure CMC, which is used for food and pharmaceutical applications.[citation needed] An intermediate "semi-purified" grade is also produced, which is typically used in paper applications such as the restoration of archival documents.[citation needed]

Structure and properties