HYDROXYPROPYL CELLULOSE
Revised specification prepared at the 63rd JECFA (2004) and published in FNP52 Add 12 (2004) superseding specifications prepared at the 29th JECFA (1985) and published in FNP 52.An ADI ‘not specified’ was established for modified celluloses at the 35th JECFA (1989).
SYNONYMS Cellulose hydroxypropyl ether; modified cellulose; INS No. 463
DEFINITION An ether of cellulose containing hydroxypropyl substitution prepared from cellulose by treatment with alkali and propylene oxide. The article of commerce can be specified further by viscosity.
Chemical names Hydroxypropyl ether of cellulose, cellulose hydroxypropyl ether
C.A.S. number 9004-64-2
Chemical formula [C6H7O2(OH)X(OCH2CHOHCH3)y(OCH2CH[Rw]CH3)z]n
where x + y + z = 3 y + z (1+w) = not greater than 4.6 R = A substituent comprising "w" hydroxypropoxy groups
One of many possible structural formulae for the repeating unit of a hydroxypropyl cellulose with molar substitution of 3.0 and a degree of
polymerization of n, showing a monomeric hydroxypropyl substitution at C2 and a dimeric hydroxypropyl substitution at C6.
Formula weight Unsubstituted structural unit: 162.14 Trisubstituted structural unit: 336.37
Macromolecules: from about 30 000 (n about 100) up to about 1 million (n about 2500)
Assay Not more than 80.5% of hydroxypropoxy groups equivalent to not more than 4.6 hydroxypropyl groups per anhydroglucose unit on the dried basis
DESCRIPTION Slightly hygroscopic, white or off-white, almost odourless, granular or fibrous powder
FUNCTIONAL USES Emulsifier, thickener, stabiliser, binder, suspension agent, film coating
