Introduction to Cellulose Ethers from Dow Construction ChemicalsCellulose 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.

Cellulose EthersTechnical Overview and Product Guide

Your Cellulose EtherApplication SpecialistDow Construction Chemicals offers a robust portfolio of cellulose ether products for construction applications. We use our proven chemistry, world-class 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

HydroxypropylMethylCelluloseOH

OHHO

Could react

ONa

ONaHO

CelluloseAlkali

CelluloseNaOH

“Activating”H H

HCl

- NaCl

H H

HCl

- NaCl

MonochloromethaneEthylene Oxide

MonochloromethanePropylene Oxide

WALOCEL™ M / METHOCEL™ Products

WALOCEL™ M Products

O

OMeHO

OH

O

OMeHO

OH

HydroxyethylMethylCellulose

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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 thickening the aqueous phase Stability

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

systems• Untreated products must first be thoroughly dispersed to prevent

lumping

• Ease of dispersion and dissolution• Control of solubilization rate

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.

Table 1: General Properties of Dow Construction Chemicals Cellulose Ethers

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.

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Product Viscosity,mPa•s Properties

WALOCEL™ VP-M-49125 8,000• Modified HPMC grade• Long open time• Very high slip resistance

WALOCEL™ MKS 10000 PF 60 10,000• Modified HPMC grade• Long open time• Very high slip resistance

WALOCEL™ MKX 15000 PF 01 15,000• Medium viscosity HEMC grade• Recommended for standard quality polymer- and non-polymer-

modified thin-sets

WALOCEL™ MW 15000 PFV 15,000• Medium viscosity HEMC grade• Delayed hydration• Suitable for dry mix and ready-to-use

METHOCEL™ 327 20,000• Multipurpose• Good open time• Good slip resistance

WALOCEL™ MKX 20000 PP 10 20,000• Modified HEMC grade• Good open time• Good workability

WALOCEL™ MKX 25000 PF 25 L 25,000• Modified HEMC grade• Long open time• Good slip resistance• Good workability

WALOCEL™ MKX 40000 PF 01 40,000• High viscosity HEMC grade• Recommended for standard quality polymer and non-polymer-

modified thin-sets

WALOCEL™ MW 40000 PFV 40,000 • High viscosity HEMC grade with delayed hydration• Suitable for dry mix and ready-to-use

WALOCEL™ MKX 45000 PP 10 45,000• High viscosity HEMC grade• Good open time• Good workability • Moderate slip resistance

WALOCEL™ MKX 45000 PF 20 L 45,000• Modified HEMC grade• Long open time• Excellent workability • Good slip resistance

WALOCEL™ MKX 60000 PF 01 60,000 • Very high viscosity HEMC• High water retention/open time at low dosage rates

WALOCEL™ MW 60000 PFV 60,000• Very high viscosity HEMC• Delayed hydration• High water retention/open time at low dosage rates

WALOCEL™ M-20678 80,000 • 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 80,000mPa•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.

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 GUIDE

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(1)50–80,000mPa•s,2%solution,measured with a Haake rotational rheometer, 20°C, shear rate 2.55 s-1

Product Viscosity,mPa•s Properties

WALOCEL™ MK 3000 PF 3,000 Excellent workability

WALOCEL™ MKW 4000 PF 01 4,000 Easy workability

WALOCEL™ MKX 6000 PF 01 6,000• Good workability • Good application

properties

Product Viscosity,mPa•s Properties

METHOCEL™ CP 7331 100 • Less segregation • Outstanding flow

METHOCEL™ CP 1119 300 • Less segregation • Excellent flow

WALOCEL™ MK 400 PF 400 • Less segregation • Very good flow

WALOCEL™ MT 400 PFV 400 • Less segregation • Very good flow

WALOCEL™ MKW 6000 PF 01 2,000 • Minimal segregation • Good flow

Tile Grouts

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.

Table 3: Cellulose Ether Products for Tile Grouts

Self-Leveling Underlayments

Cellulosics impart water retention and lubricity to improve flow and pumpability, minimize segregation and more.

Table 4: Cellulose Ether Products for Self-Leveling Underlayments

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

Decorative Renders Skim Coats

WALOCEL™ MKW 4000 PF 01 4,000 Easy workability •

WALOCEL™ MKX 6000 PF 01 6,000 • Good workability• Good application properties •

WALOCEL™ MKS 10000 PF 60 10,000 • Excellent open time• Excellent workability for feather finish •

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 •

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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

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 •

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

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

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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

AdhesivesTape Joint

CompoundsCaulks & 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 • Delayed solubility • Easy workability •

WALOCEL™ M-8805 30,000 • Delayed solubility • Easy workability •

WALOCEL™ MW 40000 PFV 40,000 Delayed solubility • •

WALOCEL™ CRT 40000 PV 40,000 Delayed solubility •

WALOCEL™ M-8804 40,000 • Delayed solubility • Good body and open time •

WALOCEL™ M-8809 40,000 • Delayed solubility • Easy workability •

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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This document is designed as a general overview of Dow Construction Chemicals products. Always review specific product literature/safety data sheets for current information. Please contact your local Dow Construction Chemicals representative for detailed technical information applicable to individual requirements.

NOTE: Any photographs of end-use applications in this document represent potential end-use applications but do not necessarily represent current commercial applications, nor do they represent an endorsement by Dow of the actual products. Further, these photographs are for illustration purposes only and do not reflect either an endorsement or sponsorship of any other manufacturer for a specific potential end-use product or application, or for Dow, or specific products manufactured by Dow.

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Customer Notice: Dow strongly encourages its customers to review both their manufacturing processes and their applications of Dow products from the standpoint of human health and environmental quality to ensure that Dow products are not used in ways for which they are not intended or tested. Dow personnel are available to answer your questions and to provide reasonable technical support. Dow product literature, including safety data sheets, should be consulted prior to use of Dow products. Current safety data sheets are available from Dow.

NOTICE: No freedom from infringement of any patent owned by Dow or others is to be inferred. Because use conditions and applicable laws may differ from one location to another and may change with time, the Customer is responsible for determining whether products and the information in this document are appropriate for the Customer’s use and for ensuring that the Customer’s workplace and disposal practices are in compliance with applicable laws and other governmental enactments. The product shown in this literature may not be available for sale and/or available in all geographies where Dow is represented. The claims made may not have been approved for use in all countries. Dow assumes no obligation or liability for the information in this document. References to “Dow” or the “Company” mean the Dow legal entity selling the products to customer unless otherwise expressly noted. NO WARRANTIES ARE GIVEN; ALL IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE ARE EXPRESSLY EXCLUDED.

Printed in the U.S.A.Published May 2012

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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.