CELLOSIZEHydroxyethyl Cellulose

ThickenerBinderStabilizerFilm FormerProtective Colloid

Hydr

oxye

thyl

Cellu

lose

Contents3. Introduction3. Performance Characteristics4. Applications8. Chemistry9. Product Line10. Environmental Impact10. FDA and EPA Status11. Explosibility of Dusts11. Hygroscopicity12. Solubility in Organic Solvents12. Preparation of Solutions13. Solution Properties14. Viscosity of Solutions18. Blending Different Grades20. Effect of Enzymatic Action and Preservatives20. Aqueous Solution Compatabilities22. Films of CELLOSIZE™ Hydroxyethyl Cellulose22. Film Compatibility24. Test Methods26. Packaging26. Product Safety

Figures8. Figure 1 - Structure of Cellulose8. Figure 2 - Idealized Structure of CELLOSIZE Hydroxyethyl Cellulose11. Figure 3 - Relative Humidity vs. Equilibrium Moisture Content at 25°C12. Figure 4 - Effect of Distilled Water pH on Dissolving Characteristics of

QP Type14. Figure 5 - Typical Relationships Between Shear Rates and Solution

Viscosities15. Figure 6 - Brookfield Viscosity/Shear Rate Correlation16. Figure 7 - Typical Effect of Aqueous Solution Concentration on Viscosity

of High- and Medium-Viscosity Grades17. Figure 8 - Typical Effect of Aqueous Solution Concentration on Viscosity

of Low-Viscosity Grades18. Figure 9 - Viscosity vs. Temperature of Two-Percent Aqueous Solutions19. Figure 10 - Blending Chart

Tables9. Table 1 - Viscosity Ranges of Aqueous CELLOSIZE

Hydroxyethyl Cellulose Solutions9. Table 2 - Typical Properties of CELLOSIZE Hydroxyethyl Cellulose11. Table 3 - Solubility of CELLOSIZE Hydroxyethyl Cellulose in Organic

Solvents13. Table 4 - Typical Properties of Aqueous Solutions of CELLOSIZE

Hydroxyethyl Cellulose20. Table 5 - Aqueous Solution Compatibilities with Gums and Resins21. Table 6 - Aqueous Solution Compatibilities with Inorganic Salts23. Table 7 - Typical Properties of Unplasticized Films23. Table 8 - Typical Impact Resistance of Films23. Table 9 - Film Compatibility with Water-Soluble Gums and Resins

2

3

Performance Characteristics

ThickeningCELLOSIZE hydroxyethylcellulose helps contributea desired body in paintsand cosmetics. In manyapplications, thickening iscombined with suspension,stabilization, dispersion, andwater retention to producedesired results.

PseudoplasticitySolutions of high-viscositygrades are pseudoplastic andthin out under shear. Latexpaints must stay on the brushor roller, yet flow out easily onbrushing or rolling and thenlevel out to reduce brush or lapmarks. Hair shampoos mustpour rich and heavy from thecontainer and yet thin out, feelwet, and disperse easily whenrubbed between the hands andapplied to the hair.

Salt ToleranceBecause CELLOSIZE HEC isnonionic, it is stable in solutionwith high concentrations ofsalts. In electroplating, thisproperty contributes to brighterand more uniform plating. Incosmetics, it can be used tothicken underarm deodorantsdespite the high salt levels ofsuch products. In latex paints,tolerance of borates, silicates,and carbonates is important inmaintaining desired viscosity.

Film FormingFilms of CELLOSIZE HECcan be applied from water solu-tions. In paper manufacturing,coatings that are impervious tooils, greases, and most solventscan be prepared. This propertyalso contributes to excellent inkholdout in paper-sizingformulations.

In textiles CELLOSIZE HECserves as a warp size, protectingfibers from mechanical abuse.The film-forming property canbe used advantageously as atemporary protective coatingduring processing and shipping.When protection is no longerneeded, the coating can bewashed off.

Water RetentionCELLOSIZE HEC helpsmaintain the water contentof formulations at desiredlevels. This property enablesformulators to reduce theamount of water needed in aformulation because of themore efficient use made ofwater in the presence of smallquantities of CELLOSIZEHEC. Without water-retainingand binding properties,cement-based mortars wouldlose their adhesion and strength,and ceramic powders wouldlose their plasticity underpressure.

CELLOSIZE hydroxyethyl cellulose (HEC) is a

nonionic, water-soluble polymer that can thicken,

suspend, bind, emulsify, form films, stabilize,

disperse, retain water, and provide protective colloid

action. It is readily soluble in hot or cold water and

can be used to prepare solutions with a wide range

of viscosities. It has outstanding tolerance for

dissolved electrolytes.

CELLOSIZE HEC offers narrow viscosity ranges,

consistent viscosity reproducibility, and excellent

solution clarities.

Applications

AgricultureCELLOSIZE hydroxyethylcellulose effectively suspendssolid toxicants in water-basedsprays.

When used in a spray, it helpsbind the toxicant to the foliage.

As a film-former, it can beuseful as a seed coating.

As a thickener for sprayemulsions, CELLOSIZE HECreduces drift and permits moreefficient spray directly onfoliage.

Building MaterialsCELLOSIZE HEC is usedin gypsum, cement, limeand organic plasters, tileadhesives, and mortars. Incement formulations, it is usedas a retarder and moisture-retaining agent.

In the manufacture ofwallboard, it is a componentof emulsions for surfacetreatment to improve releasefrom press and to prepare thesurface to accept paint orsurface coatings. It is also usedas a thickening agent inwallpaper paste.

CELLOSIZE HEC improvesthe workability of gypsumplaster by increasing the openand trowelling times. It issuperior to other cellulosics incompressive and flexuralstrengths and in dimensionalstability.

Cosmetics and DetergentsCELLOSIZE HEC is aneffective film-former, binder,thickener, stabilizer, anddispersant in shampoos, hairsprays, neutralizers, creams andlotions. In liquid detergents and“waterless” hand cleaners, it isused as a thickener andprotective colloid. The solubil-ity of CELLOSIZE HEC atelevated temperatures simplifiesand speeds up productiontechniques. Preparations basedon CELLOSIZE HEC areknown to feature improvedbody, smoothness, andsilkiness.

Latex PolymerizationThe molar substitution of theprotective colloid grades ofCELLOSIZE HEC was chosento optimize its role in theinitiation of catalyst-protectivecolloid polymerization sites, inthe stabilization of the growingpolymer particles, and in thestabilization of the finishedlatex to freeze-thaw andmechanical shear.

The concentration of protectivecolloid in the polymerizationcharge is a critical variable inthe control of latex viscosity,polymer particle size, andfreedom of the emulsion fromscrap.

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Oil ProductionCELLOSIZE HEC is aviscosifier in workover andcompletion fluids. It helpsprovide clear, low-solid fluidsthat impart minimum forma-tion damage. Fluids thickenedwith CELLOSIZE HEC areeasily broken with acid,enzymes, or oxidating agentsto maximize the potential forhydrocarbon recovery.

In fracturing fluids,CELLOSIZE HEC acts as acarrier for proppants. Thesefluids can also be easily brokenby the above techniques.

Drilling fluids formulated withCELLOSIZE HEC, using thelow-solids concept, offerincreased penetration rateswith good borehole stability.Property inhibited fluids can beused in drilling medium-to-hardrock formations, as well asheaving or sloughing shales.

In cementing operations,CELLOSIZE HEC reduceshydraulic friction of the slurryand minimizes water loss to theformation.

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Paint ThickeningIn latex paint formulations,CELLOSIZE HEC offers easeof solution, low-foaming,thickening efficiency, andimproved color developmentand stabilization. Its non-ioniccharacter contributes stabiliza-tion over a wide pH range andpermits broad formulatinglatitude. The QP type is ofparticular interest wherecontrolled hydration is desired,as in the direct addition of thethickener to the water at thebeginning of the pigment grind.

The higher viscosity grades(QP 15000H, QP 30000H,QP 52000H, and QP 100MH)have been developed primarilyfor use in latex systems wherethe water-soluble componentsmust be reduced to a minimum.

Paper and InksCELLOSIZE HEC is a usefulgloss and ink hold-out size forpaper and paperboard.Advantages of printing papersize with CELLOSIZE HECinclude superior definition ofprinted images, lower costbecause of lower penetration ofthe top coat, and high gloss. Itcan be applied to paper orpaperboard at either size pressor the calender stack. In papersizing, 0.1 to 0.5 pounds per1000-square feet (0.5 to 2.5grams per square meter) is theusual application.

CELLOSIZE HEC increasesthe water retention of coatingcolors, particularly withcoatings containing highproportions of latex, where thepenetration of adhesive into thebase sheet must be controlled.As a starting point, add about0.5 to 1.0 percent ofCELLOSIZE HEC QP 09,based on pigment. If higherviscosity can be tolerated,substitute CELLOSIZE HECQP 3 or QP 40 forCELLOSIZE HEC QP 09.

The use of CELLOSIZE HECalso contributes to improvedgrease resistance. For oil- andgrease-proof coatings, useabout two pounds per 1000-square feet (10 grams persquare meter) of surface.Coatings may be applied byblade, air-knife, or roll coating.

CELLOSIZE HEC offers otherdesirable properties in paperapplications, including its readysolubility in water; compatibil-ity with most gums, resins, andinorganic salts; low biologicaloxygen demand; low foamingtendency, and its ability to formclear films.

In ink manufacture,CELLOSIZE HEC is used forthe production of waterborneduplicating inks that dry rapidlywithout setoff or bleeding.

Textile SizesSolutions of CELLOSIZE HECmake useful warp sizes that canbe removed from the fiber bywater-washing. In combinationwith other resins, CELLOSIZEHEC has found wide applica-tion in textile finishes. It is alsoused as a water-soluble formingsize and binder in glass fibers,and as finishing and bindingagent in leather pastes.

Textile Latex Coatings,Binders, and AdhesivesLatex adhesives thickenedwith CELLOSIZE HEC arepseudoplastic; that is, they thinunder shear but rapidly returnto high viscosity to controlstrike-through and improveprint definition.

CELLOSIZE HEC controlswater release and permitscontinuous running withoutbuildup of adhesive on the printrolls. Controlled water releaseallows more open time forgood acceptance of flock andformation of a better adhesivefilm without noticeablyextending drying time.

CELLOSIZE HEC QP 09L,at 0.2 to 0.5 percent, improvesmechanical stability in non-woven binder formulations,reduces wet picking at nip rolls,and increases the wet strengthof the final product.

CELLOSIZE HECQP 52000H is an effectivethickening agent for nonwovenprint bonding formulations,providing exceptional patterndefinition.

The properties that makeCELLOSIZE HEC an excellentthickener for acrylic-basedbinders and nonwoven flockadhesives commend it forthickening textile backcoatingand laminating formulations.It is compatible with manyfillers and effective at lowconcentrations.

Textile Carpet Dyeingand PrintingIn carpet dyeing, such as theKüsters continuous dyeingsystem, very few thickenerscan match the thickeningefficiency of CELLOSIZE HECQP 100MH. None can matchits total combination ofproperties: thickening efficiency,ease of dissolving to lump-freesolutions, low levels of impuri-ties to interfere with dye pickupand color development, freedomfrom insoluble gels that wouldintroduce dye specks on finishedgoods, and uniformity ofproperties within a narrowspecification range.

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Household ProductsCELLOSIZE HEC finds utilityin many household products asa thickener, stabilizer, andbinder. For example, in liquiddetergents and cleaners, it actsas a rheology modifier and asan efficient thickener, impartinggood body structure, apseudoplastic rheology, and asmooth “feel” to products.

The nonionic structure ofCELLOSIZE HEC offers goodcompatibility with surfactantsand other formulationingredients.

Other formulations for whichCELLOSIZE HEC can berecommended include fabricsofteners, shoe polishes, andas a binder in products thatregulate the release of activeingredients, such as airfresheners.

Special ApplicationsFire FightingAdditive to enhance theblanketing properties of firefighting foam. Useful inpreparing “thickened water”for fire fighting.

FoundriesImproves the green strengthand collapsibility in cementsand and sodium silicate sandsystems.

MicroscopyFilm-forming, dispersingagent for the preparation ofmicroscopic slides.

PhotographyThickening agent in filmprocessing fluids with highsalt concentrations.

Fluorescent Tube CoatingsBinder for phosphors influorescent tube coatings.Stable dispersions can beapplied evenly at a controlledrate. Selection of grades andconcentrations controlsbinding and green strength.

Electroplating andElectro-RefiningProtective colloid unaffectedby high concentrations ofelectrolytes. In cadmiumplating, for example,CELLOSIZE HEC promotesuniform depositions.

CeramicsGreen strength binder forceramics.

Electrical CablesWater-blocking powder toprevent moisture-penetrationof broken cables.

ToothpasteThickening agent.

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Figure 1 • Structure of Cellulose

Figure 2 • Idealized Structure of CELLOSIZE Hydroxyethyl Cellulose *

H

OH

O

CH2OH

CH2OH

OH

H

H

H

OH

H

OH

H

H H

O

O

H OH

n

H

OH

O

CH2OCH2CH2OCH2CH2OH

CH2OCH2CH2OH

OH

H

H

H

OH

H

OH

H

H H

O

O

H OCH2CH2OH

n

* See explanation for D.S. and M.S.

8

Chemistry

CELLOSIZE HEC is namedafter its two components:cellulose and hydroxyethylside chains. Cellulose itself isa water-insoluble, long-chainmolecule consisting ofrepeating anhydroglucoseunits, as shown in Figure 1.

In the manufacture ofCELLOSIZE HEC, a purifiedcellulose is reacted withsodium hydroxide to producea swollen alkali cellulose.This alkali-treated cellulose ismore chemically reactive thancellulose. By reacting the alkalicellulose with ethylene oxide,a series of hydroxyethylcellulose ethers is produced.In this reaction, the hydrogenatoms in the hydroxyl groupsof cellulose are replaced byhydroxyethyl groups, whichconfer water solubility to theproduct. Figure 2 shows anidealized structure ofCELLOSIZE HEC.

The manner in which ethyleneoxide is added to cellulose canbe described by two terms:Degree of substitution (D.S.)and molar substitution (M.S.).The degree of substitutiondesignates the average numberof hydroxyl positions on theanhydroglucose unit that havebeen reacted with ethyleneoxide. Since each anhydro-glucose unit of the cellulosemolecule has three hydroxylgroups, the maximum valuefor D.S. is three. See Figure 1.

Molar substitution is definedas the average number ofethylene oxide molecules thathave reacted with eachanhydroglucose unit. Oncea hydroxyethyl group isattached, it can further reactwith additional groups in anend-to-end formation. Aslong as ethylene oxide isavailable, this reaction cancontinue, theoreticallywithout limit. See Figure 2.

Product Line

CELLOSIZE HEC ismanufactured in a variety ofviscosity grades. Theseversions differ principally intheir aqueous solutionviscosities and are offered tooptimize performance inspecific CELLOSIZE HECapplications.

For a two-percent by weightaqueous solution, viscositiesrange from as low as 10mPa•s up to 100,000 mPa•s.The number of theCELLOSIZE HEC viscositygrade refers to its averagetwo-percent solution viscosity.

Table 1 • Viscosity Ranges of Aqueous CELLOSIZE Hydroxyethyl Cellulose Solutions

Solution CELLOSIZE HEC Viscosity Range Spindle Number RPM

Concentration % Grade LVF Brookfield at

25°C, mPa•s

5 WP/QP 09L 75-112 1 30WP/QP 09H 113-150 1 30

EP 09 90-160 1 30QP 3L 215-282 2 60

2 QP 40 80-125 1 30WP/QP 300 300-400 2 60

EP 300 250-400 2 60ER 4400 4800-6000 4 60QP 4400H 4800-6000 4 60QP 10000H 6000-7000 4 60

1 QP 15000H 1100-1500 3 30QP 30000H 1500-2400 3 30

WP/QP 52000H 2400-3000 3 30QP 100MH 4400-6000 4 30ER 15000 1100-1500 3 30ER 30000 1500-1900 3 30ER 52000 2400-3000 3 30

*Your local technical sales representative will be glad to help you in selecting the most appropriate type for yourspecific applications.

Table 2 • Typical Properties of CELLOSIZE Hydroxyethyl Cellulose

Appearance White to cream-colored, freely flowing powderBulk Density, lb/ft3 (g/cm3) 19-38 (0.3-0.6)Decomposition Temperature, °F (°C) About 400 (205)Softening Point, °F (°C) >285 (140)Particle Size 100% through U.S. 20 mesh (840 micron)Specific Gravity at 20/20°C 1.30-1.40Volatile Matter, % by wt 5Standard Bag Size (net) 50 lb or 25 kgStandard Pallet Size

Bag 40Net Weight 2000 lb or 1000 kg

Two types of CELLOSIZEHEC are produced forspecific dissolving purposes.QP type materials disperserapidly, while WP typeshydrate quickly. In addition,CELLOSIZE HEC is availablein several grades, which havebeen specifically developed toimprove their resistance toenzyme attack.

They are designated ER type,enzyme resistant. Table 1details CELLOSIZE HECproduct line by viscosity anddissolving type.

Table 2 shows some physicalproperties common to allviscosity grades ofCELLOSIZE HEC.

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Environmental Impact

Aqueous solutions ofCELLOSIZE hydroxyethylcellulose do not appear topose any ecological problems.Based on test proceduresconsistent with ASTM andEPA guidelines, CELLOSIZEHEC solutions were evaluatedagainst aquatic organisms. Atthe highest test concentrationsused, no toxic effects wereobserved for Daphnia magna(maximum concentrationequals 1,000 mg/liter) or forfathead minnows (maximumconcentration equals 5,000mg/liter). In addition,CELLOSIZE HEC solutionsshowed no inhibitory effectson bacterial biomass(unacclimated sewagemicroorganisms) at concen-trations up to 1,000 mg/liter(1).

While cellulosic polymers arenot considered to be persis-tent in the environment, theircomplete breakdown tocarbon dioxide and wateris relatively slow unlessextended biotreatment orwaste treatment facilityacclimation procedures areused to enhance the naturalmetabolic rates.

In the laboratory, the potentialrate at which a chemical candegrade in an unacclimatedwater treatment system isoften measured by theBiochemical Oxygen Demand(BOD) test(2). This standardtest involves exposing a testmaterial to an unacclimatedsewage seed and measuringthe oxygen demand of thesystem. Calculations ofpercent bio-oxidation arecorrelated to the amount ofoxygen required to degradethe chemical completely tocarbon dioxide and water.CELLOSIZE hydroxyethylcellulose exhibits a ChemicalOxygen Demand (SOC)(2)

of 1.41 mg O2/mg activepolymer. Using this methodol-ogy, CELLOSIZE QP 4400Happears to be approximatelyfive percent degraded in fivedays and approximately 12percent degraded in twentydays.(1) Procedure detailed in G.M.

Alsop, G.T. Waggy, and R.A.Conway Bacterial GrowthInhibition Test, Journal of WaterPollution Control Federation, 52,(10), October, 1980.

(2) Standard Methods for theExamination of Water andWastewater, 14th edition.American Public HealthAssociation, 1976, Parts 507and 508.

FDA Regulations (21 CFR) Permitted Uses

73.1001 (b) Diluent in color additivemixtures used in coloringexternally-applied drugs.

175.300 Component of resinous andpolymeric coatings applied asa continuous film over metalor any substrate suitable forrepeated use in contact withfood.

175.105 Component of food-packagingadhesives.

176.170 Component of the coated or176.180 uncoated food contact surface

of paper and paperboard incontact with fatty, aqueous,and dry foods.

177.1210 Manufacture of closures withsealing gaskets for foodcontainers.

177.1390 (c)(2)(ii) Component of adhesives forhigh-temperature laminates,when separated from the foodcontact layer by a functionalbarrier.

182.99 Exempt from the requirementof a residue tolerance whenused as an adjuvant added topesticide use dilutions by agrower or applicator prior toapplication to the rawagricultural commodity.

EPA Regulation (40 CFR) Permitted Uses

180.1001 (c) Exempt from the requirementof a residue tolerance whenused as an inert ingredient inpesticide formulations appliedto growing crops or to rawagricultural commodities afterharvest.

FDA and EPA Status

CELLOSIZE hydroxyethylcellulose (HEC) is presentlyapproved, under regulationsof the United States Food andDrug Administration (FDA),for use in indirect foodapplications, such as food-packaging adhesives and canand paper coatings.

CELLOSIZE HEC has notbeen cleared for direct useas a component of foodproducts.

Under regulations of theEnvironmental ProtectionAgency (EPA), it is exemptfrom the requirement of aresidue tolerance in pesticideformulations.

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Explosibility of Dusts

Dusts of CELLOSIZE HEC,like those of many organiccompounds, are explosive ifmixed with air or otheroxidants in critical propor-tions and in the presence ofan ignition source. Thesedusts represent a hazardsimilar to that of othercellulosic derivatives and ofmany widely-used organicsolids. With KST values lessthan 200 bar m/s,CELLOSIZE HEC isidentified as a Class I dust.Explosion-venting design maybe accomplished by utiliza-tion of NFPA-68 guidelines.Though measured minimumignition energy levels aregreater than 300 mJ, care

should be taken to preventignition from commoncauses, such as cutting andwelding, stray electric current,and hot surface temperatures.To minimize the potential forelectrostatic dischargeproblems, avoid conveyingthrough electrically noncon-ductive piping. Also, normalgood housekeeping proce-dures should be practiced tocontrol the explosibility ofdust. At Dow’s CELLOSIZEHEC production facilities,CELLOSIZE HEC dust isconveyed in air, in groundedequipment, with explosionventing on receivers and dustcollectors. In the presence offlammable gases, liquids, orvapors, CELLOSIZE HECshould be handled in inertnitrogen-blanketed equipment.

Figure 3 • Relative Humidity vs. Equilibrium MoistureContent at 25°C

Table 3 • Solubility ofCELLOSIZE HydroxyethylCellulose in Organic Solvents

Solvent Solubility

Hydrocarbons

Xylene IBenzene IPetrolene IKerosene IChlorinated Hydrocarbons

Chlorobenzene ICarbon Tetrachloride ITrichloroethylene IEthylene Dichloride IMethylene Chloride IAlcohols/Glycol Ethers

Butanol ICARBITOL™ Solvent IEthanol (95%) IMethyl CELLOSOLVE™ Solvent IMethanol IAldehydes

Butyraldehyde PFormalin SKetones

Acetone IDiethyl Ketone IAcids

Acetic Acid PFormic Acid SEsters

Amyl Acetate, Primary IEthyl Acetate IAmines

Ethylenediamine SPyridine IDiethylenetriamine SEsters

Isopropyl Ether IEthyl Ether I1,4-Dioxane IOils

Mineral Oil ICottonseed Oil ILard Oil ILinseed Oil IOther

Dimethyl Formamide SDimethyl Acetamide SDimethyl Sulfoxide SPhenol S

S =SolubleI =InsolubleP =Partially soluble

Hygroscopicity

As packaged, the moisturelevel (volatile matter) ofCELLOSIZE HEC viscositygrades is typically five-percentby weight. However, like allother cellulose ethers,CELLOSIZE HEC ishygroscopic.

If stored in open or looselycapped containers, themoisture content will changeto an equilibrium valuedetermined by the relativehumidity of the environment.Therefore, to obtain thedesired viscosity duringformulation, compensationfor the moisture weightchange must be made. Theeffect of relative humidity onthe equilibrium moisturecontent of CELLOSIZE HECis shown in Figure 3.

50

40

30

20

10

00 20 40 60 80 100

Eq

uili

bri

um

Mo

istu

re C

on

ten

t, %

Relative Humidity, %

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Solubility in Organic Solvents

CELLOSIZE hydroxyethylcellulose (HEC) is insolublein most organic solvents, asshown in Table 3. In a few ofthe polar solvents, it is eitherswollen or partially soluble.

Preparation of Solutions

To prepare CELLOSIZE HECsolutions easily, good agita-tion and pH control arerecommended.

Dispersing of QP TypeAgitation of solutions at apH of 7.0 or lower is recom-mended to make initialdispersions. After theCELLOSIZE HEC is well-dispersed and with agitationmaintained, the hydration ratemay be accelerated by adjust-ing the pH to alkaline rangesand /or by increasing thetemperature.

Below pH 7.0, the hydrationrate of QP grades is decreased.Above pH 7.0, the hydrationrate is increased.

Dispersing of WP TypeTo achieve adequate disper-sions, the WP types ofCELLOSIZE HEC requiremore careful techniques thanthe QP types. Solution takesplace more readily if agglom-eration is avoided. Sprinklethe WP type of CELLOSIZEHEC into vigorously stirredwater.

Control the agitation togive maximum shear andminimum air entrainment.Continue until a clear,homogenous solution isobtained. Depending on theparticular application, slurryaddition may be used tocontrol agglomeration and toaccelerate the rate of solution.

Pre-WettingCELLOSIZE HEC can beslurried in a water-miscibleliquid (alcohols, acetone,diacetone alcohol, glycols)before adding it to water.

Dry-BlendingCELLOSIZE HEC can beblended with other drymaterials, either soluble orinsoluble, before adding it tothe formulation. Pigments,fillers, or dyes can thus beused to aid in the dispersion.

Figure 4 • Effect of Distilled Water pH on Dissolving Characteristics of QP Type

Surfactant AdditionThe addition of about 0.01percent surfactant to thewater can aid in wetting anddispersing any WP type ofCELLOSIZE HEC.

Effect of pHThe effect of pH on thedissolving characteristics of aQP type CELLOSIZE HEC isillustrated in Figure 4.

Six Important Steps toOptimum Performance1. Agitate continuously while

adding thickener. Do notstop the mixer until solutionis clear and smooth.

2. Quickly sift the thickenerinto the solution. Do notdump or shovel it in.

5000

4000

3000

2000

1000

00 20 40 60 80 100

pH 8.0 pH 6.8

Vis

cosi

ty a

t 25

°C, m

pa•

s

Elapsed Time, Minutes

3. Water properties influencedissolving time. Note thathydration time decreases aspH and temperature areincreased.

4. Do not add anything thatwill raise the pH of thewater until the thickenerparticles have been wettedout. Two or three minutesmixing will usually accom-plish this. Raising the pHthereafter markedlyincreases the rate ofsolution.

5. Add an effective preserva-tive at the earliest conve-nient point in the process.

6. Store CELLOSIZE HEC intightly closed containers toprevent absorption ofmoisture.

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Solution Properties

The most important uses ofCELLOSIZE hydroxyethylcellulose involve its aqueoussolutions. The wide range ofviscosity grades allowspreparation of solutions ina similarly wide range ofproperties, extending frommoderate viscosities withusual colloidal properties tomaximum viscosities withminimum dissolved solids.CELLOSIZE HEC is thechoice for many thickeningjobs because it offers thefollowing advantages:• Thickening Efficiency• Good Compatibility• Excellent Stability• Low Insolubles• Low Foam Characteristics• Good Protective Colloid

Activity• Solution Clarity• Viscosity Reproducibility

Thickening EfficiencyAny desired thickeningefficiency can be achievedwith the wide selection ofviscosity grades available.

Good CompatibilityCELLOSIZE HEC is compat-ible in solutions with mostinorganic salts, as well as witha broad range of gums andresins.

Table 4 • Typical Properties of Aqueous Solutions of CELLOSIZE Hydroxyethyl Cellulose

2% Aqueous Solutions

Refractive Index at 20°C 1.336 pH 6 to 7Specific Gravity at 20°C 1.003 Freezing Point, °C 0

Surface Tension of Aqueous Solutions, at 25°C, mN/m

QP/WP 09 QP/WP 300 QP 4400H QP 52000H QP 100MH

Solution Concentration, %

0.01 65.7 66.4 66.3 65.9 66.10.1 65.4 65.8 65.3 65.4 65.41.0 65.1 65.5 65.8 66.1 66.32.0 65.0 66.3 67.3 - -5.0 64.7 - - - -10.0 65.9 - - - -

Excellent StabilityCELLOSIZE HEC contrib-utes stability in a number ofways. It is shear stable andcan be formulated easily. Itis a protective colloid thatimproves the stability of manydispersions. It enhancesfreeze-thaw stability andpromotes shelf-life stability.

Typical PropertiesTypical physical propertiesof aqueous solution ofCELLOSIZE HEC are shownin Table 4.

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Viscosity of Solutions

Viscosity DeterminationBecause different viscometersvary in their shear rates,they will indicate differentviscosities for the same non-Newtonian solution. At thesame shear rate, differentviscometers should give thesame viscosity value. Thetype of viscometer and theconditions under which thetests were run must, there-fore, be specified with theviscosity data.

Some relationships betweenshear rate and the apparentviscosity of selected solutionsare illustrated in Figure 5. Itroughly associates these shearrates with general applicationsand with commonly usedviscometers.

Effect of ShearThe solutions of the mediumand high viscosity grades ofQP 4400H, QP 10000H,QP 15000H, QP 30000H,QP 52000H, and QP 100MHare non-Newtonian and showa high degree of pseudo-plasticity. The solutions oflow-viscosity grades show alow degree of pseudoplasticityand are nearly Newtonian.This trend is illustrated inFigure 5.

Figure 5 • Typical Relationships Between Shear Rates and Solution ViscositiesTwo-Percent Concentration Except Where Indicated

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1,000,000

100,000

10,000

1,000

100

10

0.01 0.1 1 10 100 1,000 10,000 100,000Shear Rate, sec-1

Vis

cosi

ty a

t 25

°C, m

Pa•

s

QP 100MH

QP 30000H

QP 4400H

QP 15000H

QP 52000H

QP 300

QP 40

5%, QP 3

5%, QP 09

Pouring of

SolutionsMixing

Stirring

Application ofPaint and Coatings

Brushing

RollingSpraying

Suspensionof Particles

Levelingof Paints

HoepplerFalling Ball

InterchemicalPrecisionRotationalViscometer

Brookfield

Haake Rotovisco Bob & Cup

Haake Rotovisco Cone & PlateCapillary

Zahn Type Cup

Because solutions of thehigh-viscosity grades ofCELLOSIZE HEC are highlypseudoplastic, their viscositiesare influenced by shear rate.At low rates of shear, themolecular arrangement ofhydroxyethyl cellulose israndom, resulting in a highdegree of chain entanglementand consequent high viscosity.At high rates of shear, themolecules become orientedwith respect to the directionof flow, thereby decreasingthe resistance to flow. Thus,viscosity, defined as the ratioof shear stress to shear rate,decreases with increasing shearrate, as shown in Figure 5. Asmolecular weight decreases,polymer chains are lessentangled and theirpseudoplastic characterbecomes less pronounced.

Shear rate is an importantconsideration in estimatingthe quantity of any grade ofCELLOSIZE HEC requiredto yield a certain viscosityunder the actual shearconditions of an industrialapplication. Shear rate shouldalso be considered in obtain-ing laboratory measurementsthat are reproducible.

Figure 6 serves as a guide inpredicting typical viscositiesof various solution ofCELLOSIZE HEC as obtainedby any of the Brookfieldmodel-rpm combinations.For example, a two-percentsolution of QP 4400H mayyield 25°C Brookfield viscosi-ties of 13 500, 7000, or 5800mPa•s, depending on whetherthe viscometer was operatedat 6, 12, or 60 rpm.

Figure 6 • Brookfield Viscosity/Shear Rate CorrelationTwo-Percent Concentration Except Where Indicated

15

Shear Rate, sec-1

500,000

100,000

10,000

1,000

100

10

0 4 8 12 16 20 24

Bro

okf

ield

Vis

cosi

ty a

t 25

°C, m

Pa•

s

QP 100MHQP 52000HQP 30000H

QP 15000HQP 4400H

QP 300

QP 3 (5%)

QP 40

QP 09 (5%)

LVF 3 6 30 60LVT

RVF

RVF 2 10 20 100100

RVT

HAF 1 10HBF

HAT 1 10 20 50 100HBT

2 10 20

5 10 20 50 100

Spindle chosen to give 15° or greater dial deflectionrpm

By proper grade selection,almost any solution viscositycan be achieved usingCELLOSIZE HEC. Viscosityis also affected by concentra-tion, temperature, and pH.

Shear StabilityAlthough they arepseudoplastic, solutions ofCELLOSIZE HEC are notdegraded and suffer nopermanent loss of viscosity byshearing. Excellent shearstability is exhibited by allgrades. Measurements obtainedin laboratory equipment ontwo-percent solutions showedno change in viscosity after 15minutes exposure to a highshear rate of 8200 reciprocalseconds. When solutions ofCELLOSIZE HEC aresubjected to high shear ratesthat are inherent in industrialequipment, shear stability isnormally unaffected.

Effect of ConcentrationAs the concentration ofCELLOSIZE hydroxyethylcellulose is increased,solution viscosities increaserapidly. The viscositiesproduced by several grades ofCELLOSIZE HEC at variousconcentrations are shown inFigures 7 and 8. The sametarget viscosities can beproduced by using differentsolution concentrations of thevarious grades ofCELLOSIZE HEC.

For example, one percent ofQP 30000H or three percentof QP 300 will provide about1500 mPa•s. While theviscosities of these solutionswill be similar, their flowproperties differ. The firstsolution exhibits pseudoplasticcharacteristics, while thesecond is nearly Newtonian.

Figure 7 • Typical Effect of Aqueous Solution Concentration on Viscosity ofHigh- and Medium-Viscosity Grades

0 .5 1.0 1.5 2.0 2.5 3.0 3.5

10,000

1,000

100

10

Resin Concentration, % by Weight

Bro

okf

ield

Vis

cosi

ty a

t 25

°C, m

Pa•

sQP 100MH

QP 52000H

QP 30000H

QP 15000H

QP 4400H

16

Effect of TemperatureIncreasing the temperatureof a solution of CELLOSIZEHEC reduces the solutionviscosity. Cooling the solutionto the original temperaturerestores original viscosity.This effect, illustrated inFigure 9, is the only influencetemperature has on solutionsof CELLOSIZE HEC. Incontrast to some alkyl/hydroxyalkyl cellulose ethers,CELLOSIZE HEC does notexhibit a gel point (cloudpoint), and CELLOSIZE HECsolutions may be subjected tofreeze-thaw conditions, usedat high temperature, or boiledwithout precipitation or gellingproblems. Because the effectof temperature on viscosity islarge, temperature control isessential in accurately measur-ing viscosity.

Effect on pHVariations in pH betweenabout 2 and 12 have littleeffect on the viscosity ofsolutions of CELLOSIZEHEC. Solution viscosities tendto be lower beyond theselimits. They may also be lessstable if hydrolysis occurs atlow pH, or if oxidation occursat high pH. Such reactions arecharacteristic of manypolymers.

Figure 8 • Typical Effect of Aqueous Solution Concentration on Viscosity ofLow-Viscosity Grades

1000

100

10

1

0 2 4 6 8 10 12 14Resin Concentration, % by Weight

Bro

okf

ield

Vis

cosi

ty a

t 25

°C, m

Pa•

s

QP 300 QP 40 QP 3L QP 09H/QP 09L

17

Blending Different Grades

The solution viscosities thatcan be achieved withCELLOSIZE HEC are notlimited by the grades available.Intermediate viscosities can beachieved through appropriateblends of two or more gradesof different viscosity. Eitherdry powder or solutions ofthe resin may be blended toobtain the intermediateviscosity, which may beestimated by either of thefollowing empirical methods:

Calculation MethodAn estimate can be made withthe equation:

log VAB = a log VA + b log VB

Where VAB is the estimated viscosityof the blend of resins A and B, VA isthe viscosity of resin A, VB is theviscosity of resin B, a is the weightfraction of resin A, and b is theweight fraction of resin B.

A multi-component blend canbe calculated by adding theterm c log VC, etc., to theright-hand side of the

equation. Note that the sumof the weight fractions a, b,etc., of the components in theblend must be 1.00. Also, allof the viscosity measurementsmust be at the same conditionsof concentration andtemperature.

Blending Chart MethodA similar estimate of blendviscosity and compositionmay be made with a straightedge and a sheet of semiloggraph paper, as shown inFigure 10. To use the graph:

100,000

10,000

1,000

100

10

1

10 20 30 40 50 60 70 80Temperature, °C

Vis

cosi

ty, m

Pa•

s

52000H

30000H

15000H

4400H

300

40

3

09

1. Locate the solution viscosi-ties of the resins that are tobe blended on the verticallines A and B on the graph.

2. Draw a tie-line connectingthese two viscosities.

3. Locate the desired blendviscosity on vertical lineA and extend this pointhorizontally until itintersects the viscositytie-line.

4. Extend this intercept pointdownward to the blendcomposition scale and readthe blend composition.

18

Figure 9 • Viscosity vs. Temperature of Two-Percent Aqueous Solutions

Figure 10 • Blending Chart

19

This composition will havethe preselected viscosity.Conversely, starting with aselected composition, theresulting blend viscosity maybe read by reversing thesesteps. Note that a singleviscosity tie-line applies onlyto a specific pair of resins; allother pairs have their owntie-lines.

For example, a line has beendrawn in Figure 10 for ablend of CELLOSIZE HECQP 300 and QP 15000H.Two-percent solutionviscosities of these particularsamples are 280 and 17000mPa•s. In this specificexample, a 50-50 mixture ofthe two resins would have anestimated viscosity of 2200mPa•s. Likewise, a viscosityof approximately 4600 mPa•scan be obtained by blending68 percent of QP 15000Hwith 32 percent of QP 300.Identical data are obtained byuse of the equation given inthe preceding subsection.

Low- 0 10 20 30 40 50 60 70 80 90 100Viscosity 100 90 80 70 60 50 40 30 20 10 0Resin A Blend Composition, % by Weight

20,000

10,0009,0008,000

7,000

6,000

5,000

4,000

3,000

2,000

1,000900800

700

600

500

400

300

200

100

Vis

cosi

ty, m

Pa•

s

17000 mPa•sQP 15000H

4600 mPa•s

2200 mPa•s

280 mPa•sQP 300

50% QP 30050% QP 15000HViscosity 2200 mPa•s

32% QP 30068% QP 15000HViscosity 4600 mPa•s

Line A Line B

Aqueous SolutionCompatibilities

Gums and ResinsCELLOSIZE hydroxyethylcellulose is at least partiallycompatible with mostwater-soluble gums and resinsin common use (see Table 5).It can be combined with thesematerials to form clear,homogenous solutions of highviscosity. Thus, the formulatorhas at his command manycombinations from which toselect the best system for hisneeds. Among the water-soluble gums and resins listedin Table 5, the soluble metalsalts of alginic acid have asynergistic effect on thesolution viscosity ofCELLOSIZE HEC. Theaddition of small amountsof these various salts to asolution of CELLOSIZE HECincreases the viscosityseveralfold. This combinationis particularly effective inproducing gels.

Inorganic SaltsCELLOSIZE HEC can besalted out of solution likeother organic solutes, but itssalt tolerance is much greaterthan most other water-solublecellulose derivatives.

CELLOSIZE HEC is an etheralcohol and is not ionizable inaqueous media. It cannot beprecipitated from solution byreaction with heavy metalions, as can anionic cellulosics.The nonionic character ofCELLOSIZE HEC makes itan outstanding colloidalthickener for solutionscontaining high concentrationsof electrolytes.

Table 5 • Aqueous Solution Compatibilities with Gumsand ResinsCompatible

Borated DextrinDextrinGum ArabicGum KarayaGuar GumGum TragacanthHydroxypropyl MethylcelluloseMethyl CelluloseSodium AlginateSodium Carboxymethyl Cellulose

Partly Compatible

CaseinGelatinPolyvinyl AlcoholStarch

Incompatible

Zein

20

Effect of Enzymatic Actionand Preservatives

Like other conventionalcellulosics, QP and WP typesof CELLOSIZE hydroxyethylcellulose are subject toenzymatic degradation withconsequent loss of viscositysolution. Enzymes, whichcatalyze this degradation, areproduced by many bacteriaand fungi present in theindustrial environment. Toprevent enzymatic degrada-tion from occurring, take thefollowing precautions:

1. Maintain goodhousekeeping. Make sureall tanks, lines, pumps,and equipment are cleanand are treated routinelywith a broad spectrummicrobiocide. e.g.,UCARSAN™ Sanitizer 420.

2. Keep containers closedwhen not in use.

3. Add a preservative atthe earliest possible point.Add it during the prepara-tion of a stock solution ofthickener or during theaddition of dry thickener.

Some end uses are regulatedand require appropriatepreservatives. Any regulatedsubstance must meet theFederal/State regulationsfor safety, health, andenvironment.

4. Make fresh stock solutionsat least once a month. Donot use stock solutions thatare more than one monthold. Or, consider using oneof the ER grades ofCELLOSIZE HEC.

In general, lower viscositygrades will tolerate a higherconcentration of salt than thehigher viscosity grades. Dataon the compatibility ofCELLOSIZE HEC withhigher concentrations of salts

are given in Table 6. Thegrades for which the data aretabulated are WP 09 andQP 4400H. CELLOSIZEHEC is compatible with atleast 10-percent solutions ofall salts listed in Table 6.

Surface Activity andDefoamingAqueous solutions ofCELLOSIZE HEC show aslight reduction in surfacetension (63 to 69 mN/m)over that for pure water(72.4 mN/m). Since surfaceactivity relates to foaming,solutions of CELLOSIZEHEC can foam whenvigorously agitated, thoughthe tendency to do so isrelatively slight and less thanmost cellulosic water-solublepolymers. Occasionally,foaming may cause trouble.If any difficulty is encountered,a small amount (0.2 percent)of an antifoaming agent willgenerally alleviate the problem.The defoamer may be addedto the water prior to solutionpreparation if its effect on Awater-dispersible defoamer isrecommended.

Table 6 • Aqueous Solution Compatibilities with Inorganic SaltsSaturated solutions were tested except where concentration at saturation exceeded 50 percent.To 15 grams of each salt solution, 1 ml of the solution of CELLOSIZE hydroxyethyl cellulosewas added.

Results Observed

Salt Salt Concentration* 10% QP 09 2% QP 4400H

Carbonate, Sodium 50% Ppt(a) PptChloride, Ammonium Saturated No ppt No pptChloride, Calcium Saturated No ppt No pptChloride, Ferric 50% No ppt No pptChloride, Ferrous 50% No ppt No pptChloride, Magnesium Saturated No ppt No pptChloride, Sodium Saturated No ppt No pptChloride, Stannic Saturated No ppt No pptChloride, Zinc 50% No ppt No pptChlorohydride, Aluminum 50% No ppt No pptDicromate, Sodium 50% No ppt No pptFerricyanide, Potassium Saturated No ppt V sl ppt(b)

Ferrocyanide, Potassium Saturated Ppt PptMetasulfite, Potassium Saturated No ppt No pptNitrate, Aluminum Saturated No ppt No pptNitrate, Ammonium Saturated No ppt No pptNitrate, Calcium Saturated No ppt No pptNitrate, Chromic Saturated No ppt No pptNitrate, Magnesium Saturated No ppt No pptNitrate, Silver 50% No ppt No pptNitrate, Sodium Saturated No ppt SL ppt(c)

Nitrate, Zinc Saturated No ppt No pptPerborate, Sodium Saturated No ppt No pptPhosphate, Disodium Saturated Ppt PptSulfate, Aluminum Saturated Ppt PptSulfate, Ammonium Saturated Ppt PptSulfate, Chromic Saturated Ppt PptSulfate, Ferric Saturated No ppt No pptSulfate, Magnesium Saturated Ppt PptSulfate, Sodium Saturated Ppt PptSulfate, Zinc Saturated Ppt PptSulfite, Sodium Saturated Ppt PptThiosulfate, Sodium Saturated Ppt Ppt(a) Precipitation(b) Very Slight Precipitation(c) Slight Precipitation*At room temperature

21

22

Water-Soluble FilmsWater-soluble films are usuallyprepared by evaporatingsolutions of the appropriateresin onto a substrate. Theunplasticized film possessesthose general propertiesshown in Table 7.

For applications that requiregreater flexibility andelongation, films based onCELLOSIZE HEC can beplasticized. By adding five to30 percent plasticizer, elonga-tion and flexibility areincreased. The followingplasticizers have proveneffective:• Glycerol• Ethanolamines• Glycols• Sorbitol• Sulfonated Oils• Polyglycols

Plasticizers have a profoundeffect on the impactresistance of films based onCELLOSIZE HEC. A com-parison of the impact resis-tance of representativeplasticized and unplasticizedfilms of CELLOSIZE HECQP 09 at different relativehumidities is shown inTable 8.

Films of CELLOSIZEHydroxyethyl Cellulose

Films of good clarity andmoderate strength can beprepared from solutions ofCELLOSIZE HEC. The filmsare odorless, insensitive tolight, possess good oil andgrease resistance, and areinsoluble in most organicsolvents. By appropriatemodification with plasticizers,films with a wide variety ofphysical and chemical proper-ties can be produced.

Water-Insoluble FilmsFilms of CELLOSIZE HECare normally water-soluble,but may be insolubilized byreactions that crosslink thepolymer chains. This is usuallydone by the reaction of a poly-functional compound withthe available hydroxyl groupsin the polymer. Effectiveinsolubilizing reagents includedialdehydes (such as glyoxaland glutaraldehyde),dimethylol urea, and water-soluble urea- and melamine-formaldehyde resins. Almostany degree of water-insolubilitymay be obtained.

Film Compatibility

In addition to their compat-ibility with plasticizers, filmsof CELLOSIZE hydroxyethylcellulose can be modified withvarious natural gums andsynthetic resins to changetheir properties. A list of thegums and resins compatiblewith CELLOSIZE HEC isgiven in Table 9.

Table 8 • Typical Impact Resistance of Films

Impact Resistance

ft lb/in2 (KJ/m2)

10% 50%Relative RelativeHumidity Humidity

Film at 10°C at 5°CCELLOSIZE HEC QP 09 7 (14.7) 13 (27.3)CELLOSIZE HEC QP 09+

Diethylene Glycol, 20% 22 (46.2) 47 (98.7)

Table 9 • Film Compatibility with Water-Soluble Gumsand ResinsCompatible

Borated DextrinDextrinGum ArabicGum KarayaGum TragacanthSodium AlginateSodium Carboxymethyl Cellulose

Partly Compatible

CaseinGelatinMethyl CellulosePolyvinyl AlcoholStarch

Incompatible

Zein

23

Table 7 • Typical Properties of Unplasticized FilmsDensity g/cm3 1.4Tensile Modulus psi (kg/cm2) 4400 (310)Elongation to Break, % 6 to 7Elastic Modulus psi (kg/cm2) 85000 (5950)Color ColorlessRefractive Index 1.50

Test Methods

I-Volatiles(a) Accurately weigh 5.0 g of

the sample into a tared3-in x 1-in (6.0-cm X4.3-cm) can.

(b) Place the can in a 110°Cconstant-temperature ovenfor on hour, leaving the lidoff during the heatingperiod.

(c) Cover the can in the oven,remove the can from theoven, and cool in adesiccator for a minimumof five minutes.

(d) Re-weigh the can to thenearest 0.1 mg.

(e) Calculation:

A-B x 100 + Volatiles, % by weightC

A = g sample plus can prior to heating

B = g sample plus can after heating

C = original g sample before heating

II-Viscosity of AqueousSolutionsFollowing the procedurerecommended by ASTMD2364-89 and used by othermanufacturers of cellulosicthickeners, Dow reportssolution viscosity specifica-tions on a calculated drybasis. This means that thevolatiles content (principallymoisture) is first determinedand, when solutions areprepared, sufficient additionalthickener is used to make upfor the contained volatiles.The volatiles content ofCELLOSIZE HEC is fromabout three to five percent.

(a) Apparatus: BrookfieldSynchro-Lectric Viscom-eter, Model LVF or LVT.Constant temperaturebath capable of maintain-ing a temperature of 25 ±0.2ºC.

(b) Procedure: First determinethe volatiles contentaccording to Test Method1 - Volatiles. Calculate thedry basis sample weightnecessary to make thedesired concentration350 g of test solution, asfollows:

Weight of sample, g = 100 x A100-B

where:A = desired dry weight of sampleB = percentage of moisture in the

sample weighed.

The actual amount ofsample will be slightlygreater than the approxi-mate weight shownbecause of the adjustmentfor the volatiles content.

Add the sample, weighedto the nearest 0.1 mg, tothe container. Then addsufficient distilled water,

weighed to the nearest0.01 g, to make a totalof 350 g of solution.Calculate the amount ofwater as follows:

Weight = 350-S

where S = sample weight.

(c) Connect the impeller tothe stirring motor, andstir until the sample iscompletely dissolved. Thesuggested stirring time isthree hours. The stirringtime should be increasedwhen the viscosity deter-mination fails to checkwithin the prescribedlimits.

NOTE: Stirring times prob-ably can be reduced on somegrades of CELLOSIZE HEC(low-viscosity grades) and onthe one-percent solutions ofhigh-viscosity grades, accord-ing to the following table:

Specified Solution Approximate

percent by weight Sample, g

1.0 3.52.0 7.05.0 18.0

Grades Concen- Stirring Time, Hours

tration, % QP WP

09;3 5 1.5 1.5 minimum, or untilall lumps are dissolved

40;300 2 2 2 minimum, or until alllumps are dissolved

4400H; 10000H 2 315000H; 30000H;52000H; 100MH 1 3.8

24

25

(d) Bring the solution to atemperature of 25 ± 0.5°C,if necessary, and place inthe constant temperaturebath (25 ± 0.2°C). Leavein bath until solution hasreached a temperature of25 ± 0.2°C. Approximatelyone-half hour will berequired.

(e) Remove the solution fromthe bath and determine theBrookfield viscosity. ForQP 4400 and QP 10000H(two-percent solution), stirfor three minutes at 500 to900 rpm before measuringthe viscosity.

NOTE: The room tempera-ture ideally should be kept asclose to 25°C as possible tominimize temperature varia-tion in the solutions duringthe additional stirring period.The temperature of thesolution should be checkedagain immediately beforedetermining the viscosity.

Use the spindle-rpm combi-nations shown in Table 1 todetermine the viscosities ofthe indicated grades ofCELLOSIZE HEC.

Allow the spindle to rotateuntil a constant reading isobtained.

Viscosity = Dial Reading x Factor

Report the results asBrookfield viscosity at 25°C,stating the solution concen-tration and the spindle andspeed used.

III-Dry Basis andAs-Packaged ViscositiesDetermining solution viscosi-ties on a calculated dry sampleprovides a useful point ofreference. Many users ofcellulosic thickeners, however,do not make an adjustmentfor volatiles but use thematerial directly from thepackage. Viscosities on an“as-packaged” basis will beabout 10% lower because ofthe dilution effect of volatiles.

IV-Hydration TimeHydration time is defined asthe time required to dissolveHEC in an aqueous system.The thickener grades ofCELLOSIZE HEC (QP 300through QP 100MH) aremeasured using a pH 7.2

buffer rather than distilledwater to yield hydration timedata that are more consistentwith industry standards andmore relevant to mostcustomer applications. Formost thickener grades ofCELLOSIZE HEC, typicalhydration times in pH 7.2buffer are between five and15 minutes. Lower molecularweight grades (AP 09 throughQP 40) are measured indistilled water, with typicalhydration times ranging fromfive to 30 minutes. Either a

Brookfield or Brabenderviscometer can be usedfor these hydration timemeasurements.

V-Additional MethodsAdditional testing methodscan be found in ASTMD2364-89, “StandardMethods for HydroxyethylCellulose.”

Packaging

All grades of CELLOSIZEHEC are packaged in 30-pound or 25-kilogram bags.•The bags are easy to

palletize.• They are extra strong.• They open easily.• They save valuable

storage space.• The advantages of stretch-

wrap palletizing areavailable when you order aminimum of 2000 poundsor 1000 kilograms of asingle product. In stretch-wrap palletizing, polyethylenefilm is wrapped around aloaded pallet. The protectivecovering keeps the bags dry,positions them firmly, andprotects them from damagein transit.

26

Product Safety

When considering the use of anyDow products in a particularapplication, you should reviewour latest Material Safety DataSheets and ensure that the useyou intend can be accomplishedsafely. For Material Safety DataSheets and other product safetyinformation, contact Dow at thenumbers on the back cover.Before handling any otherproducts mentioned in the text,you should obtain availableproduct safety information andtake necessary steps to ensuresafety of use.

27

*

NOTICE: No freedom from any patent owned by Seller or others is to be inferred. Because use conditions and applicable laws may differ from one location toanother and may change with time, Customer is responsible for determining whether products and the information in this document are appropriate for Customer’suse and for ensuring that Customer’s workplace and disposal practices are in compliance with applicable laws and other governmental enactments. Seller assumesno obligation or liability for the information in this document. NO WARRANTIES ARE GIVEN; ALL IMPLIED WARRANTIES OF MERCHANTABILITY ORFITNESS FOR A PARTICULAR PURPOSE ARE EXPRESSLY EXCLUDED.

Published March 2002

Printed in U.S.A. *Trademark of The Dow Chemical Company Form No. 325-00001-0302 AMS

For more information, complete literature, and product samples,you can reach a Dow representative at the following numbers:

From the United States and Canada:call 1-800-447-4369fax 1-989-832-1465

In Europe:toll-free +800 3 694 6367†

call +32 3 450 2240fax +32 3 450 2815

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