Cellulose Ethers
Technical Overview and Product Guide
Introduction to Cellulose Ethers from Dow
Construction Chemicals
Cellulose ethers are water-soluble polymers derived from cellulose,
the most abundant polymer in nature. For more than 60 years,
these versatile products have played an important role in a host of
applications, from construction products, ceramics and paints to
foods, cosmetics and pharmaceuticals.
For construction products, cellulose ethers act as thickeners, binders,
film formers and water-retention agents. They also function as
suspension aids, surfactants, lubricants, protective colloids and
emulsifiers. In addition, aqueous solutions of certain cellulose ethers
thermally gel, a unique property that plays a key role in a surprising
variety of applications. This valuable combination of properties is not
found in any other water-soluble polymer.
The fact that so many useful properties are simultaneously
present and often act in combination can be a significant economic
advantage. In many applications, two, three or more ingredients
would be required to do the same job performed by a single cellulose
ether product. In addition, cellulose ethers are highly efficient, often
yielding optimal performance at a lower concentration than that
required with other water-soluble polymers.
Dow Construction Chemicals offers a wide array of cellulosic
products, including methyl cellulose, hydroxyethyl cellulose and
carboxymethyl cellulose. Methyl cellulose ethers are most widely
used for many applications in the building and construction industry.
Your Cellulose Ether
Application Specialist
Dow Construction Chemicals offers a robust
portfolio of cellulose ether products for construction
applications. We use our proven chemistry, worldclass research capabilities and experience in the
building and construction industry to remain current
on the industry’s ever-changing trends and help bring
you the innovations of tomorrow.
Employing our application development and
manufacturing expertise to offer solutions based on
customer needs, Dow Construction Chemicals can
help you take performance to the next level. We look
forward to working with you to develop innovative
solutions for your products and making sure that
they’re just the right fit. And we’ll be here to respond
quickly with technical service and support.
Chemistry of Cellulose Ethers
Our business offers methyl cellulose ethers in two basic types:
• Hydroxyethyl methyl cellulose (WALOCEL™)
• Hydroxypropyl methyl cellulose (METHOCEL™ and WALOCEL)
Both types have the polymeric backbone of cellulose, a natural carbohydrate that contains a basic repeating structure of
anhydroglucose units (see Figure 1). During the manufacture of cellulose ethers, cellulose fibers are heated with a caustic
solution that, in turn, is treated with methyl chloride, and either propylene oxide or ethylene oxide, yielding hydroxypropyl
methyl cellulose or hydroxyethyl methyl cellulose, respectively. The fibrous reaction product is purified and ground to a fine,
uniform powder.
Special-grade products have also been formulated to meet the requirements of specific industries.
Our cellulose ether products are available in three different forms: powder, surface-treated powder and granular. The type of
product being formulated influences which form to select. In most dry-mix applications, untreated powder is typically used,
whereas for ready-mix applications, in which the cellulosic powder is added directly to water, surface-treated powder or
granular forms are preferred.
Figure 1: Chemistry of Cellulose Derivatives
2
Monochloromethane
Ethylene Oxide
Cl
“Activating”
Cellulose
Alkali
Cellulose
NaOH
OH
HO
OH
Could react
HO
ONa
H
OH
Hydroxyethyl
Methyl
Cellulose
O
HO
OMe
H
- NaCl
WALOCEL™ M / METHOCEL™ Products
Monochloromethane
OH
Propylene Oxide
Cl
ONa
H
WALOCEL™ M Products
H
H
H
- NaCl
Hydroxypropyl
Methyl
Cellulose
O
HO
OMe
General Properties
General properties common to our cellulose ethers are listed here. Individual products exhibit these properties to varying degrees and may have
additional properties desirable for specific applications. For more information, consult your Dow Construction Chemicals representative.
Table 1: General Properties of Dow Construction Chemicals Cellulose Ethers
Property
Details
Advantages
Binding
Used as high-performance binders for extruded fiber-cement materials
Green strength
Emulsification
Stabilize emulsions by reducing surface and interfacial tensions and by Stability
thickening the aqueous phase
Film formation
Form clear, tough, flexible water-soluble films
• Excellent barriers to oils and greases
• Films can be made water-insoluble via crosslinking
Lubrication
Reduces friction in cement extrusion; improves hand-tool workability
• Improved pumpability of concrete, machine grouts and spray
plasters
• Improved workability of trowel-applied mortars and pastes
Nonionic
Products have no ionic charge
• Will not complex with metallic salts or other ionic species to form
insoluble properties
• Robust formulation compatibility
Solubility (organic)
Soluble in binary organic and organic solvent/water systems for select
types and grades
Unique combination of organic solubility and water solubility
Solubility (water)
• Surface-treated/granular products can be added directly to aqueous
• Ease of dispersion and dissolution
systems
• Untreated products must first be thoroughly dispersed to prevent
• Control of solubilization rate
lumping
pH stability
Stable over a pH range of 2.0 to 13.0
• Viscosity stability
• Greater versatility
Surface activity
• Act as surfactants in aqueous solution
• Surface tensions range from 42 to 64 mN/m(1)
• Emulsification
• Protective colloid action
• Phase stabilization
Suspension
Controls settling of solid particles in aqueous systems
• Anti-settling of aggregate or pigments
• In-can stability
Thermal gelation
Occurs to aqueous solutions of methyl cellulose ethers when heated
above a particular temperature
• Controllable quick-set properties
• Gels go back into solution upon cooling
Thickening
Wide range of molecular weights for thickening water-based systems
• Range of rheological profiles
• Pseudoplastic shear thinning rheology approaching Newtonian
• Thixotropy
Water retention
Powerful water-retention agent; keeps water in formulated systems
and prevents loss of water to atmosphere or substrate
• Highly efficient
• Improved workability and open time of dispersion-based systems
such as tape joint compounds and aqueous coatings, as well as
mineral-bound building systems such as cement-based mortars and
gypsum-based plasters
(1)
The surface tension of water is 72 mN/m; a typical surfactant has a surface tension of 30 mN/m.
3
PRODUCT GUIDE
Cement-Based Tile Adhesives (CBTA)
Our products enable performance of thin-set mortars via water retention and with pseudoplastic rheological performance. Achieve
creamy and easy workability and consistency, high water retention, improved wetting to the tile, excellent open time and adjustment
time, and more.
Table 2: Cellulose Ether Products for Cement-Based Tile Adhesives (CBTA)
Product
Viscosity, mPa • s
WALOCEL™ VP-M-49125
8,000
WALOCEL™ MKS 10000 PF 60
10,000
WALOCEL™ MKX 15000 PF 01
15,000
WALOCEL™ MW 15000 PFV
15,000
METHOCEL™ 327
20,000
WALOCEL™ MKX 20000 PP 10
20,000
WALOCEL™ MKX 25000 PF 25 L
25,000
WALOCEL™ MKX 40000 PF 01
40,000
WALOCEL™ MW 40000 PFV
40,000
WALOCEL™ MKX 45000 PP 10
45,000
WALOCEL™ MKX 45000 PF 20 L
45,000
WALOCEL™ MKX 60000 PF 01
60,000
WALOCEL™ MW 60000 PFV
60,000
WALOCEL™ M-20678
80,000
4
Properties
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Modified HPMC grade
Long open time
Very high slip resistance
Modified HPMC grade
Long open time
Very high slip resistance
Medium viscosity HEMC grade
Recommended for standard quality polymer- and non-polymermodified thin-sets
Medium viscosity HEMC grade
Delayed hydration
Suitable for dry mix and ready-to-use
Multipurpose
Good open time
Good slip resistance
Modified HEMC grade
Good open time
Good workability
Modified HEMC grade
Long open time
Good slip resistance
Good workability
High viscosity HEMC grade
Recommended for standard quality polymer and non-polymermodified thin-sets
High viscosity HEMC grade with delayed hydration
Suitable for dry mix and ready-to-use
High viscosity HEMC grade
Good open time
Good workability
Moderate slip resistance
Modified HEMC grade
Long open time
Excellent workability
Good slip resistance
Very high viscosity HEMC
High water retention/open time at low dosage rates
Very high viscosity HEMC
Delayed hydration
High water retention/open time at low dosage rates
Ultra high viscosity HEMC
High water retention/open time at low dosage rates
The wide range of
viscosity grades of
our cellulose ethers
(from 50 to more than
80,000 mPa • s(1)) gives
formulators a variety of
choices to balance their
thickening and rheology
needs, as well as the
desired level of other
performance properties.
50 – 80,000 mPa • s, 2% solution,
measured with a Haake rotational
rheometer, 20°C, shear rate 2.55 s-1
(1)
Tile Grouts
Self-Leveling Underlayments
Cellulose ethers function as a water retention and suspension
aid. Discover easy workability, good adhesion to the edges of the
tiles, low shrinkage, high abrasion resistance, good toughness and
cohesion, and more.
Cellulosics impart water retention and lubricity to improve flow and
pumpability, minimize segregation and more.
Table 3: Cellulose Ether Products for Tile Grouts
Product
Viscosity, mPa • s
Properties
WALOCEL™ MK 3000 PF
3,000
Excellent workability
WALOCEL™ MKW 4000 PF 01
4,000
Easy workability
6,000
• Good workability
• Good application
properties
WALOCEL™ MKX 6000 PF 01
Table 4: Cellulose Ether Products for Self-Leveling
Underlayments
Product
Viscosity, mPa • s
METHOCEL™ CP 7331
100
METHOCEL™ CP 1119
300
WALOCEL™ MK 400 PF
400
WALOCEL™ MT 400 PFV
400
WALOCEL™ MKW 6000 PF 01
2,000
Properties
•
•
•
•
•
•
•
•
•
•
Less segregation
Outstanding flow
Less segregation
Excellent flow
Less segregation
Very good flow
Less segregation
Very good flow
Minimal segregation
Good flow
Mortars for EIFS/Skim Coat
Deliver the perfect finishing touch with improved workability, air void stabilization, adhesion, water retention and more.
Table 5: Cellulose Ether Products for Mortars for EIFS/Skim Coat
Product
Viscosity, mPa • s
Properties
Mortars for
EIFS
Skim Coats
•
WALOCEL™ MKW 4000 PF 01
4,000
Easy workability
WALOCEL™ MKX 6000 PF 01
6,000
WALOCEL™ MKS 10000 PF 60
10,000
•
•
•
•
WALOCEL™ MKW 10000 PP 01
10,000
Good air void stabilization
WALOCEL™ MKX 15000 PF 01
15,000
Multipurpose
WALOCEL™ MKW 15000 PP 30
15,000
• Good air void stabilization
• Sag resistance
•
WALOCEL™ MKW 20000 PP 20
20,000
Good air void stabilization
•
WALOCEL™ MKX 20000 PP 10
20,000
• Easy workability
• Good mesh grab
•
METHOCEL™ 327
20,000
Multipurpose
•
WALOCEL™ MKX 25000 PF 25 L
25,000
• High yield
• Good workability
• Good mesh grab
•
WALOCEL™ MKX 45000 PP 10
45,000
High water retention
WALOCEL™ MKX 45000 PF 20 L
45,000
Good workability
Good workability
Good application properties
Excellent open time
Excellent workability for feather finish
Decorative
Renders
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5
Cement-Based Plasters
Deliver better performance through improved sag resistance, workability, open time, air-void stabilization, adhesion, water retention, yield
and more.
Table 6: Cellulose Ether Products for Cement-Based Plasters
Product
Viscosity, mPa • s
Properties
WALOCEL™ MKW 15000 PP 30
15,000
• Air void stabilization
• Good standing strength
WALOCEL™ MKW 20000 PP 01
20,000
• Air void stabilization
• Good standing strength
WALOCEL™ MKW 20000 PP 20
20,000
• Air void stabilization
• Easy workability
WALOCEL™ MKW 20000 PP 30
20,000
• Air void stabilization
• Sag resistance
WALOCEL™ MKW 20000 PP 40
20,000
• Air void stabilization
• High yield
WALOCEL™ MKW 30000 PP 01
30,000
Air void stabilization
WALOCEL™ MKW 30000 PP 10
30,000
• Air void stabilization
• Easy workability
WALOCEL™ MKW 30000 PP 30
30,000
• Air void stabilization
• Sag resistance
Gypsum-Based Building Materials
Deliver the desired end result of a smooth, even and durable surface with consistent product quality and important performance features.
Table 7: Cellulose Ether Products for Gypsum-Based Building Materials
Product
Viscosity, mPa • s
Properties
Gypsum Plaster
Gypsum Fillers
WALOCEL™ MK 3000 PF
3,000
Excellent workability
•
WALOCEL™ MKX 20000 PF 40
20,000
• Reduced lump formation
• Good workability
•
WALOCEL™ MKX 30000 PF 60 E
30,000
• Easy workability
• High yield
•
WALOCEL™ MKX 35000 PP 35
35,000
Multipurpose
•
WALOCEL™ MKX 40000 PF 20
40,000
Reduced lump formation
•
WALOCEL™ MKX 70000 PP 01
70,000
High water retention
•
WALOCEL™ MKX 70000 PP 40
70,000
• Easy workability
• High water retention
•
6
Cement and Cement-Fiber Extruded Materials
Reduce friction and impart lubricity to aid in extrusion and other forming processes.
Table 8: Cellulose Ether Products for Cement and Cement-Fiber Extruded Materials
Product
Viscosity, mPa • s
Properties
WALOCEL™ MKX 60000 PF 01
60,000
High water retention
WALOCEL™ VP-M-7701
70,000
• High water retention
• High heat stability
WALOCEL™ M-20678
80,000
• High water retention
• High heat stability
Latex-Based Systems (Ready-to-Use)
A range of viscosity grades delivers good workability, delayed solubility, open time, adjustment time and more.
Table 9: Cellulose Ether Products for Latex-Based Systems (Ready-to-Use)
Product
Viscosity, mPa • s
Properties
Silicate
Renders
Plasters
Tile
Adhesives
Tape Joint
Compounds
Caulks &
Sealants
•
WALOCEL™ MT 6000 PV
6,000
Multipurpose
WALOCEL™ MW 6000 PFV
6,000
Delayed solubility
WALOCEL™ CRT 10000 PV
10,000
Delayed solubility
WALOCEL™ MW 15000 PFV
15,000
Delayed solubility
METHOCEL™ 240S
20,000
Delayed solubility
•
WALOCEL™ MK 25000 PFV
25,000
•
WALOCEL™ M-8805
30,000
•
•
•
•
WALOCEL™ MW 40000 PFV
40,000
Delayed solubility
WALOCEL™ CRT 40000 PV
40,000
Delayed solubility
WALOCEL™ M-8804
40,000
WALOCEL™ M-8809
40,000
•
•
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•
METHOCEL™ J 75 MS-N
40,000
Delayed solubility
CELLOSIZE™ QP 15000
15,000
Delayed solubility
•
CELLOSIZE™ QP 52000
50,000
Delayed solubility
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Delayed solubility
Easy workability
Delayed solubility
Easy workability
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Delayed solubility
Good body and open time
Delayed solubility
Easy workability
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7
Safety Considerations
Material Safety Data Sheets (MSDS) for WALOCEL™, METHOCEL™ and CELLOSIZE™ products are available from Dow to help satisfy your own handling, disposal and safety needs,
and those that may be required by government regulations. Such information should be requested prior to handling or use. The general information that follows is not a substitute for
the detailed safety information found in the MSDS.
Handling and Storage
During use or storage, safe handling is required to prevent dust with air from reaching explosive levels, as is true with other organic materials of similar particle size. When handling
large quantities, local applicable regulations concerning the prevention of dust explosions or those outlined in the National Fire Protection Association (NFPA) Standard: “Prevention of
Dust Explosions in Industrial Plants” should be followed. With cellulose ethers, the critical level may be reached at about 28 grams dust/m3.
Additionally, WALOCEL™, METHOCEL™ and CELLOSIZE™ products, like other organic chemicals, should not be stored next to peroxides or other oxidizing agents.
Health
As is typical when working with powders, ensure that adequate respiratory protection measures are taken. Please refer to the safety data sheet for more specific respiratory protection
measures, as well as more detailed health and safety considerations.
Flammability
Cellulose ether products are organic polymers that will burn when exposed to heat and a sufficient oxygen supply. Fires can be extinguished by conventional means, avoiding any
raising of dust by strong water jets. Dow recommends the use of water spray, carbon dioxide or powder extinguishers.
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