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CelluSiv
( Cellulose Ether Polymer Products )
CelluSiv products are an extensive family of methylcellulose (MC)
and hydroxypropyl and hydroxyethyl methylcellulose polymers that are
used globally in many industrial, building, dry mixes, household and
personal care products. They are primarily used as polymeric
surfactants, thickeners in liquid formulations, and as binders in
solid and semi-solid products.
CelluSiv products are nonionic water-soluble cellulose ether
polymers which are prepared from cellulose (pulp), a widely
distributed natural material. The cellulose is processed with
caustic soda and then treated with an etherification reagent such as
methyl chloride, propylene oxide or ethylene oxide, etc.
CelluSiv is classified into the following basic types, methyl
cellulose (MC), carboxymethyl cellulose (CMC), hydroxyethyl
cellulose (HEC), methyl hydroxyethyl cellulose (MHEC), and methyl
hydroxypropyl cellulose (MHPC) according to the kind of
etherification reagent used. Based on the applications area, these
products can be surface treated for better dispersion and
solvability for different usage conditions and parameters.
These products hold varying ratios of hydroxypropyl, hydroxyethyl
and methyl substitution, a factor which influences organic
solubility and the thermal gelation temperature of aqueous
solutions. Among the types listed above, HEC is the hardest to
dissolve in solution. However, HEC has the highest water retention
factor and holds the highest binding power in the dry mix systems.
All types of CelluSiv have the polymeric backbone of cellulose,
a natural carbohydrate that is made up of the basic repeating
structure of anhydroglucose units in the figure below.
Basic Repeating Chemical Structural Units of CelluSiv
According to the type of etherification reagent used the more
common R groups substitution in the anhydroglucose units are as in
the following chart:
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TYPES |
CHEMICAL NAMES |
R Group |
|
MC |
Methyl Cellulose |
-CH3 |
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CMC |
Sodium Carboxymethyl Cellulose |
-CH2COONa |
|
HEC |
Hydroxyethyl Cellulose |
-CH2CH2OH |
|
MHEC |
Methyl Hydroxyethyl Cellulose |
-CH3, -CH2CH2OH |
|
MHPC |
Methyl Hydroxypropyl Cellulose |
-CH3, -CH2CH(OH)CH3 |
Degree of Substitution
The amount of substituent groups (R) on the anhydroglucose units of
cellulose can be designated by weight percent or by the average
number of substituent groups attached to the ring, a concept known
to cellulose chemists as "degree of substitution" (D.S). If all
three available positions on each unit are substituted, the D.S. is
designated as 3, if an average of two on each ring is reacted; the
D.S. is designated as 2, etc.
The number of substituent groups on the ring determines the
properties of the various products. As an example CMC contains 27.5
to 31.5% methoxyl, or a methoxyl D.S. of 1.64 to 1.92.
In the MHPC, MHEC and HEC cellulose ether products, the methoxyl
substitution is still the major constituent. The molar substitution
(MS) reports the number of moles of hydroxypropyl or hydroxyethyl
groups per mole of anhydroglucose.
The degree of substitution of the various R groups determines the
viscosity, solubility, elasticity, plasticity, thermo stability,
emulsion and lubricating factors of the final product's usage
suitability.
Applications
Some of the industries using CelluSiv are as follow:
Agricultural Chemicals as suspending and dispersing aids
Bio-Adhesives
Cement based Dry and Wet mixes and Cement Plasters
Ceramics Processing, Glazes and Porcelain Enamels
Controlled Release Systems
Gypsum based plasters and Tape-Joint compounds and Crack Fillers
(Putty & Caulkings)
Household cleaners and detergents
Paints (Emulsion Based) and Paint-Removers
Paper Industries
Pharmaceutical Products
PVC Suspension Polymerization
Textile Printing
Toilet Bowl Cleaners
Transparency Films
Application examples of CelluSiv use as adhesives :
Carpet back-sizing compounds
Cigar and Cigarette adhesives
Latex adhesives
Leather processing adhesives
Plywood laminating adhesives
Wall Papers applications
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