DEVELOPMENT OF REVERSE-FLOW CAPILLARY VISCOMETER

FOR DETERMINING THE DEGREE OF POLYMERIZATION

OF DISPERSED CELLULOSE

A THESIS

SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS

FOR THE DEGREE OF M.AS'IER OF ARTS IN TEXTILES

IN THE GRADUATE DIVISION OF THE

TEXAS STATE COLLEGE FOR WOMEN

COLLEGE OF HOUSEHOLD ARTS AND SCIENCES

BY

NELL SKAGGS GLASSCOCK

DENTON, TEXAS

JUNE, 1956

The authot- lrt1shes to express her deepest gratitude

to:

Dr. Joseph c. Sherrill for his abl.e help 1n se1ect­

:Lng the reseal'ch problem. for his direction of the research­

and hi.s 1nvaluab1e interest throughout the ~ntire study;

Dr. Ramon til. Esteve tor h1s c-onstant and willing

contri.butions concerning the 1aboratocy techniques and his ·

assistance 1n the development of the equations given in this

.report;

D.P. Carl. 1-1. Conrad of the Southern Regional ReseSl'ch

Laboratory ot the United States Department of Agriculture for

suppl.yi.ng the burette viscometers used in the testing;

The many persons in the College of Household Arts

a.nd Sci.ences for their help in making the completion of ·this

thesis possible• and to Mrs. Charles O!lr fol' her help in the

.PX'eparation of the manuscript.

The author wishes to extend her appreciation to her

Parents, 111'. end Mrs. Leonal'd Alton Skaggs, fott the financial

assistance and the incentive to pursue the work.

111

. i

OF CONTliJ.NTS ~

I, I Ii T R 0 D U C T I 0 N

II. T H E 0 R Y

III • E X P E R I M E 1\f T A L PllOCEDURE

lt. MATERIJJIS .tiND METI1:0DS OF DISPERSION

l. COTTON • • ..

2. CUPRIETHYLEl\fl.ili DIA!v!Ilf".ill •

a. Copper • If • b. Ethylene Diamine ., •

3. PREPARATIOl~ OF COTTON CELLULOSE DISPEHSI/~ .. N 111 OUPRIETHYLENE DIJ\A~INE

•

•

a. Preparation of J\na.lytical Solutions

b. Mechanical Action in the Dispersion Process • • • ,

B. VISCONlE~RIC Il~STHID!ENTS •

1, TIIg ASTivi BURETTE VISCOLffiT.BR

2 • TIIE Clu'mON-FENSKE , MODIFIED OSTWALD VISC01ffiTER • •

3 • OPERATI01iAL PROCEDURE "WITH THE TEXAS ·sTATE COLLEGE FOR WOMEN PJi;VERSE-FLOW MODIFIED OST~VALD VISCOMETER •

C • Cii.LIBRATIOI'i OF TSCW RE'vJ.J:RSE-FLOW MODIFIED OST'N.t\LD VISCOZ·!lETEH

1. DETEHivlii\fA:L'ION OF EFFLtr.A TI?,UE

•

• 2. DETEI&IIHATIOU OF CAPILLARY RADIUS

iv

•

•

•

•

Iii

•

•

•

•

•

•

•

•

•

•

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Page

1

6

13

13

13

l~)

13

11.4~

15

15

16

20

20

20

21

2.5

25

25

C;t&IBRJlTION WHITE MINEltAL OILS USED FOR CALJ:BUAIDI1:1G TSOVl REVJ31~lSE-FLOW £,[QDIFI1~D OS'J:jVALD VIf300METEHS •

IV. RJ};SULTS AUD D ! S G U S S .J.: 0 N

lt • DISCUSSION OF C.ilLIBR.ATIO:tl TSCW FLOW '\1QDIFIED OSTW.ALll VISCOLWTER

1. CO:uPlPJJ.ATIONJU,I METHODS FOR DET1EHlviiJYTII~G VISCOMJTITER COiiSTJLNTS •

2. DETEB.MII~ATIOJ:T OF CONEVJ:l.AUT FROM 11lLOW bili]Ai3Ulllli~il1!.:l~T D;)!.TA •

3 • , DETERIJIII~.ATIO!i OF OOliST£J1T ]"\ltOBI J?CISEULLE f S Jl!QU .. i\.TION •

•

•

•

•

· 4 • l1.GCUR.ACY O:El DJJ;TEftfl[IN.ATI c~·riS OJ? VISCOMETER

Page

26

31

51

32

COl\fSTAltTS; A Dif3CUS8ION O:B, Et1HORS 31~

B • DET.E:Iil\1INATION OF VISCOSITY O.F CO:f\TOlif . DIBPERSIOlG" IN CUPRil~TiflLl~1ifB Diiu"VIIlTE

2, RillSULTS USIHG Tln~ TSCW R]}VE:&.SE-FLOW I\10DIFIED OSTW.t1LD VISC07IBTE1t •

3. COI,P ARISOIT Qlr TH1D INTltiN£?10 VISC0::1!~1Y OF DISP1~.HSIOHS I3Y THB AiS15::I lu~D TSCW IN'STH.Ul'~TENTS

V. SUMMARY • •

VI • F U T U H .t!i W 0 H K -l·'"'

VII • B I B L I 0 G R A P H Y • ,v ~ •

v

41

4·1

• 4-1

.J,L2

53

• 60

• 62

I. I U 1E It 0 D U C T I 0 1~ -The rapid progress in the development o:f the science

of high polymers has in considerable measure been due to

the .fact that viscosity methocis have been employed for the

characterization of the physical and chemicc:~l properties of

high molecular \Veight polymers. The viscosit;y of liquids is

a property which cen be measured with ru1 eJrtremely high de­

gree of precision. This fact has been recognized for a con-

siderable length of time, and ha.s hastened. the e)r_ploitation

of the development of high polyme:L·s-substz;;mces which are

rc-!..ther indifferent to many chemical and physical measurement

techniques because of their great complexity and. relative

lack of reactivity.

Viscosity is a fuJldam.ental precept of fluid dynamics,

the nature of which is quite beyond the scope o.f this \vriting.

Suf.fice it to say that its measurement has been st-udied and

e:.-:plored from. many different points of approach; and great

strides have been made over the past two decades on improve­

ment in the accuracy and precision of this type of meo.sure-

m.ent.

This thesis deals with the adaptation of a viscosity

measurement technique for application to dispersions of cel­

lulose in cupriethyle11e di[unine. In this Pal'ticular instance

1

2

two factors a..re required to be controlled: (a) the rate of

shear must be established for each viscosit;y rneasurement,

because of the apparent non-Newtonian behavior of the dis­

perse system cellulose - cupriethylene diamine; and (b) oy;;y­

gen must be excluded from the clete:r·mination because of the

extreme sensitivit;y of these high molecular v1eight disper­

sions.

There are numerous mechanicr-;.l procedures v1hich have

been utilized for viscosity determination. Viscosity is an

inherent property of flow, def'ined simply as resistr.il11ce to

flow. Viscometers have been proposed in many forms; all of

these measure fluid friction or slippage. The complexity

of these viscometers varies widely. Generally speal:ing,

greatest accuracy and precision consistent \-Vith c;reatest ease

of' manipulation have been obtained throu::.:;h the use of ·the

principle of the Ostwald pipette.

Ostwald viscometers have assumed many :forms dor1n ·through

the years, the most rugged and accurate being the modification

o.f Cannon and Fenske ( 3 ) • In its simplest form the Gannon­

Fenske instrument is a glass U-tube having an off-vertical

bend in the closed :portion of both arms. The theory and op­

eration of this instrument has be_;n described in many places

in the literature by Cannon ( 2 ) • This rou-tine inst;rument

cannot be used in o:x-yc;en-free syste.Bs vii thout very cum.bcr-

some adaptation, ho")':ever, so that modification han been

necessary in this ~sorl:.

3

This thesis describes tl'le development of an adaptation

of the Crumon-Fenske routine instruJllent first suggested .for

highly viscous non-J:{ewtonieJJ. polymer solution£; by Fenske,

I\laus, ru1d Dannen·brink ( 5 ) , in v;hich reverse .flow of the

fl.uid under nitrogen pressure is effectu.ated. ~!his method

permits variation of :re.t;e of shear over a wicle range encl

complete exclusion of atmospheric oxygen from the system.

In addition, it is possible to utilize the unique cha.racter­

istic of the modified Ostwald viscometer in terms of the e­

limination of all kinetic energy and end effects from the

measurements.

Viscosity is one of the more important measurements used

to characterize cellulose. Viscosity is interrelated to the

molecular weight, both of which are interrelated with the

strength of cellulose fibers, yarns, and fabric.

A number o:f disperse syste:ms for determining the vis­

cosity of cellulose are in current; use. Some involve chemi­

cal modification of the cellulose, such as ni·tration, ar.td the

deter.rnination of the viscosi-ty in an. org;a.nic sol vent. The

most commonly used method involves -the detennination of the

viscosity of cellulose in cuprrumnonium hydroxide or cupri­

ethylene di£i1Iline dispersion. The greatest :problem encoun­

tered with these dispersions is the.t the cellulose is readily

degraded by atmospheric o:~gen even in traces.

Two widely used methods for the determination of the

viscosities of disperse eellu1ose are the lun.erican Society

for Testing Materials buret;te viseometer ( 1 ) and the Cannan­

Fenske modifie.d Ostwald viscometer. It is believed that with

the l~T"IJI bui.>e·tte viscometer errors are introduced by end ef­

fects; and the timing ac.curacy is limited O"l1ing t;o the \Vide

meniscus. The Carmon-Fenske instrument, on the other he.md

is a very accu.rate viscometer; but it is very neF~ly impos­

sible to obviate oxidation completely* regardless of the pre­

cautions t!ll;:en. ( 3 ) •

In this investigation a reverse flov; single arm viscome­

ter operating under an atmosphere of nitrogen has been d.e­

vised. This instru..rnent can be manipulated simply £Uld rapio~y

under cireumst~"lces wherein rate of shear can be varied over

a wide range; and oxygen can be e~<:cluded completely.

The objectives of this study are the following:

(a) to develop a modifi.ed Ostwald-type viscome·ter for

the determination o.f the viscosity of disperse

cellulose under conditions wherein atmospheric

oxygen is excluded;

(b) to calibrate this viscomet;er end to determine the

precision of measurement of viscosities of disperse

cellulose; and

5

(c) to determine over a wide range of rate of shear

the viscosity of disperse cellulose-cupriethy~ene

diamine for typical native bale cot·hons, and to

compare values obt;ai:ned with the specially designed

modified Ostwald type and the ASTli burette type

viscometer.

Viscosity is d.efineu t~s resiste.nce to flow., or mo::~e

force opposing fluid flovJ .•

J:iathematically· it is "'syriibolized from Newton !..s ·original

hypothesis t;:,.e:~.; shear stress is p:L'O];)Ortional to shear rate

( S 1\._; R) ,, which is e:'{"_pressed t:ts follovls:

";.'\/ :· - J/LL_J du/ . ., -.-1! J:l -· , -- . 0.::1.. ...... 1

where

= force per unit area (the shee.ring stress)

d.u/d:J-: = rate of sheax·

These factO?.'S are related throu.gh the term ~ . , defined as

the coefficient of viscosity.

1J:he viscosity of Fluid in streamline, laminar, or vis-

cous flow is governed by a relationship first deduced o:Kperi-

mentally by Poiseulle, and later corx·oboratcd by vic;orous

ma-thematical treatment from 1Te'2~on 's la\V.

where

r

1l. =Trr'Pt

B 1 V ••••• g

= coefficient of viscosity, cyne-second/

square centimeter

= capillary radius, em.

= drivins pressure, dynes cm:2

6

t

1

v

= efflu:it time, sec ..

capillary length, em. 7.

efflux volume, em."

tor ease of handling, mass units are introduced as follovvs

7

-p - (? h (':) ..... - 0 -~ •· ••• ·2.

v1here

g = gravitational constant, em. -2 sec ..

h = driving head, em •.

= fluid density, gra1ns -·3 em •.

Finally, by substitution of equation 3 into equation 2:

4 -n- '7<rghe.t ( 8 1 v

L"'l which the absolute viscosity now is expressed in mass

rate of transfer, g-m. em. -l se·c:l __ _.I~· frequently. is .de·sirable to

express driving head as a product of height of fall and

density. This modifies equation L{. as follows:

.... • • • • •2

where~ is the kinematic viscosity in :stokes . , a C.iffusion

constant having the dimensional units of em. 2 soc. -l

Rigid derivation of the equation for viscosity produces

correction tGrms as follows:

-. :.·.r.·~.· •.. ~. ·~·.,_·.. · ~ ~· ........ ·~ill"' ;.... ,, ~~~ + J:l.l.'!o)t ""' ~ * •.• •le.

.of

outlet~

1ary and. in a ldnetic

inst:r-v.m.ex:rt COlls.i;ents x~, h-. l, i.Xad v· ar10 corribi.tl·O(i with 7( /B

to 11:t:-odttce the visconeter cc~ustant C c~s follows:

••• •··Z ,..~~"'1 ·Po· 11,., .. 1.1'4 ~ li";. "lhr:-t ,· ""tl ·t,.'""' 1C, G ~,;.~l,'!t."l.,. A..~ "·'tl ~l. "10· "~C ~· •. t .... · · \J't~.t.ng C a .'1 o,. .._:.. J..v~ ·t '. J.!i.r.;J · J..J.. · ~· .. \J...Wu'G ·c 01UCG ·the O:i:lly

m-easurement raauired to iiei;erru.ille kinemtxl;ic Vir:c· ··""c"·~ t:·"'"' ... . . .,., v...:.,... "'J' • :r~~he

constant C ht~~ ~11.1~ dimensit;)ncl tuli'f:;s of conti(:~4~:J,..,.:r.-,,~ _ . -1 ........ v ¥ . .. . . . ~. ~v-c. . .;...;;,, ~ce •

as the coo££ie;-.rt of vizcosi ty.

9

Shear .A c

Stress

I Shear Rate

acter.

deviate from ideal behavlo:r. o'!.rfL.'ls; to deformation o.t hi;Sh xe .. tes

to

such polymer disper·sions is relieved~ ·the a:p];;trre:nt viscosity

oi: the solution. once a.gai.n . .Utc:r:.c:HJ.ses t. unless oxidation or·

meche,nical t-vorkin.~t (in ·tht':'l. f'"'.rm of tru-bttl(0::rl.ce or t111·ottling) .... J ,. ...... ... ~ v

not 6.eforn1ed {that is, they ""t_,'!ill not flow) below fi. certain

liln1 tiug nheo.r Btre ss.

able viscosity-- in ot;her . worlt.s, viscosi t~y i~:; t. co.r:lplcd;cly

10

variable funetion of rate of shear.. The expression for rate

of shear is the follovJing:

and for the ave.rage this becomes

(du/dx) averave 0

·····2

in units of reciprocal seconds.

A little reflection will reveal that proper selec-tion

of capillary diameter aud proper adjustment of driving hea.d

will make efflux times sufiioiently high to avoid all end and

kinetic energy correction, ~~~vh.ile at the same time providing

a \Vide range o:f rate of shear.

The work of Staudinger ( 8 ) has revealed a semi-quanti­

tative relationship between the visco.sity function ar1d mole-

cul~lX size of polj~!ners dispersed in a sol vent.. It is stated

tha·t; the viscosity of a polyr.11er dispersion divided by the

viscosity of the pure solvent is termed relative viscosi·ty.

Thus

lv-here

7( = viscosity of a polymer dispersion

lfo = viscosity o£ tho pure solvent

/(r = relative viscosity

••••• 10

11

The specific viscosity is def'ined as follov1s

••••• 11 ·-where 7( s.:p is specific viscosity. Finally intrinsic vis­

cosity follows .from above

["f sp/c J ....... g

where [~ J is intrinsic viscosity and c is polymer cone en-

tration in any consistent method of expression. A plot of

l.u f sp/c against c gives a. straight line and the int;ercept

is the intrinsic viscosity, [""(}. This straight line is

described by Martins equation

ln 'f sp/c = ln ['7"(] + k [1}c ••••.• .!.2.

Relative viscosi~J, specfic viscosity, and intrinsic

viscosity all have been used by investigators in efforts to

relate viscosity with molecular weight. The modifiea equation

of Arrhenius employs relative viscosity in the following ex-

pression:

.... ·ll

where C = molal concentration based on the molecular ~eight

of the monomer

= molecular weight

k a constant de ... nendent somewhat on concen-t = tration, polymer type, solvent character

and so forth.

12

The modified expression o:f Arrhenius has been used. by

Kemp and Peters ( 7) to obtain a value for let ot 0.75 x 10-4

.for polyisobutylene dispersions in decalin.

P R 0 C E D U R E

!.!_ MAT~GRiliLS AN'D IriETHODS OF DISJ?.~.jltSION

l. COTT01I

Unprocessed cotton fibers, I>aymaster 54, 192, Aiken,

Texas 1 gro·wn in tl1e Lubbock-Abilene, Texas area was used

as the test material. Lyle • Hesler ( 6 ) supplied the

sample which is representative of an undegre.ded Texas cot·ton.

The characteristics of the co·tton are:

r~rricronaira

Upper half mean length, inches

:Maturity, per cent

Pressley Index, pounds inch-2

2 • CUPRIETHYLiflr1E JJIAillii'fE

4.1

.go

80

73-5

Cupriethylene diamine purchased from Ecusta Paper

Corporation, Pisgah Forest, North Carolina, .,~~vas used. 1.'his

material was standardized for copper and ethylene diamine

content in accordance with procedure of Straus and Levy ( 9 ) •

~Copper

A 10- ml. sample of the solution as received was removed

by means of a pipet e.nd diluted to 100 ml. in t\ volumetric

f'lask. A 25-ml. aliquot then "'v'7as wi thdrexr.a into a titrating

13

14

.flask, and 10 .ml. of a 30 weight per cent solution of potas-

sium iodide was udded. Acidification w<::1.s e~ccom]!lished throuc;h

the addition of 50 ml. o.f Ll-.0 normal su.lfuric acid. Titration

with 0•140 normal sodium thiosulf&te solution followecl. The

brown color o.f iodine faded at the endpoint;, at 1.vhich time a

f.e\v ml. of starch solution were added and the titration vras

completed.

The copper concentration was computed :from the following

expression •

. lL value of 1.03 for the molarity of copper was obtained.

b. Ethi(lene . Dia:m.ine

1\ 15-ml. a.liquot of the 1.:10 dilution previously described

was diluted '1.7ith l.llater e.ntl t.ttrated with 0.200 nor.mal sulfuric

acid to the methyl Ol."'ange endpoint. The solution changed from

dark blue to sla:te grey, ·the endpoint e.oming with the devel­

opment of the .f.irst pink tinge,.

The normalitJ· of the ethylene diarnine was computed di•

rectly from the millie qui va.lents of sulfuric acid talcen as

follows:

The ratio of Ethylene diam.ine to copper is obtained

by the follo~~~~ing equation:

15

Iiatio ....

tvhere

A = Molarity of copper

B = liormality of ethylene diamine

!i:. Pre32ara.tion 2£ imal;z:t;ica1 dolution

The ASTH procedure as modi.fied b;y Con:ra.CL and. coworlt:e:rs

( 4 ) was use<i. A weighed sa.mple of cotton was placed il1. a

red glass 1~rlemneyer flaslr; the weight of tl1.e semples \Vere

approximately 0.2, 0.18, e.nd 0.09 gin., respectively, for 0.3,

0.2, end 0.1 per cent dispersion. Another cotton s~unple v1as

placed in an oven maintained at about 105°C in order to de-

termine the moisture CO.;:ltent to correct the cotton saru:ple

v1eights accordi.n.gly.

Into the flask containing the cotton Wf;:r-e added equal

volumes first o£ water and then of 1.0 molar cupriethylene

diamine in sufficient amounts to give the desired concentration •

. An atmosphere of nitrogen was maintained in the flask during

the procedure. The flask then we..s flushed with nitrogen until

-the Zimmerman fog trap ( 12 ) indicated no trace of o:,::.ygen.

16

Dispersi;s.;]1 Process

A magnetic st;irrer ru1d a v:rrist-e.ction mechanical shalcer ·

both were st-udied as means for d.ispersing cot·ton in cupr:le-

thylene diamine. The v;ork of Thoma.s, Zimmer and cov1orkers

( 10 ) on polyiso-butylene dispersions in decalin clearly in-

dicates that decrease in molecular weigh·c brought about by

the mechanical action of the dispersion ·technique is a fv.nc-

tion of the molecular weight of tbB polymeric substa.nce being

dispersed.

In this study it was founci that althouc;h ·i;ho mechc:nical

shaker v1as the slov;er method, it we.s preferred owin~:'; to the

fact that dec;radation of the cellulose resul·t;ecl ·through the

use of the magnetic stirrer.

It was necessary to assure complete dispersion of the

cellulose in the solvent. In order to determine the disper-

sion time the following work was carried out.

Cotton and cupriethylene diamine in quantities sufficient

to produce 0.1, 0.2, 0.3 anc1 0.5 weight per cent dispersions

were mc..de up in 1~rlenmeyer flas1~:s in accordance with the pro-

cedure described in section III 3a.

The samples were worked by me~~s of the ma:3Uetic stirrer

and the mechanics~ sh&1:er for tv1o, four, si:z:, ei3ht, 10, 12,

14·, 16, lB, 20, 22, rna. 2:. hour-intervals. .hfter e&ch time

•

•

•

18

(a) 1 da::T _,

rhes. = "'· ,..,~.

(b) 3 days = ,3. .1."1les.

(c) 7 de~s = 4.15 rhea.

(d) r~r

~0 = 4.19 rhes.

T.A.BLE I ----TKE R..l\.TE OF DISPERSEMEl:rT OF J;I!fT COTTOJ:T Il\f

CU1?RIET1i1L~~lffi DIAMI1:DE AT DIF~'EHENT COl\fCEilTH.ATIONS BY T~aa 1YfJl:C1LA.r~ICAJ.: MJ_!;THODS

Dispersion Time, houx·s Concentration, per cent

2 4 I 6 I 8 I 101 12 I 14 I 16 I 18 I 20

'\ I~iAGUETIC STIRl:U;R

0.5 F F c E E D D c c I~

0 .. 3 F F D A A 1\. c .A "

0.2 E .i\.

0.1 c A

lfi.ECH.ANICAL SH.AICEJR

0.5 11: ',.-;'\ "1""',\ .. fi1 ""' J) B 1? B B .D .b .w .r:..: j

0.3 r; E D D D D F B D B

0.2 E D D D D A B B D 1!.

0.1 F F }~ D J\ J.-

KEY TO TABI.~E

A = dissolved

B = sme.ll amount undissolved

c = large amount of undissolved Sp•3CkS

D = small jelly-like balls

E = large jelly-like balls

F = undissolved

19

I 22 I 2l~

E ]3

D B

B ·A

20

1 • THE ASTr.,J: BUP~TTE VISCOMJ2T11R

The ASTIJ burette -viscometers used in this wor.k v1ere ob-

tained on loan from tlu:: Southern Regional Laborator.r. of the

J1gricultural Research l~dministration, United Sta~es De.r>art­

ment of Agriculture, l;few Orleans 19, Louisiana. These il'l-'*

strum.ents comprise a burette at the outlet of which ·cen be

attached glass orifices of variable diameter • The b1.lrette

column is etched at points to indicate fixed efflux volumes.

The determination is made under an atmosphere of nitrogen,

and the efflux time for the passage of a ltnotvn volume of

liquid through the orifice is ·the only variable requiring

measurement. The instrument (and each orifice) is ;Calibrated

against liquids of known viscosity.

The detailed description of the AST1i!I burette viscometer

is given by Conra.ct and coworkers ( 4).

2.. ~liE CAN1~01'1'-FEIJSKE MODIFIED OSTWALD VISCOMETER

This instrument has been described in exhaustive detail

by Cannon. The instruments used in these lc:.boratories were

obtained with calibration certificates from the Cannon I.-1-

strument Company, State College, Pennsylvania..

This t~~e of modified Ostwald viscometer has the' form

;.;,, I

o.f a U-tube, the a.rL!lS near ·the closea end .of which are bent about .

21

30 degrees from the vertical. The viscosity is deterrained

by £low of fluid from an upper reservoir dovm tr...rough a

capillary into a lotver reservoir. l::roper selection in te:t'ms

of capillary diameter will assure minimization of kineti.e

energy and end corrections such ·that the 1n.ea.surement of efflux

time alone allows direct computation ot viscosity. The in­

strument is calibrated against .f'lu.ids of knovm viscosity.

3 • OP.ERATIONAL PROCI~DUH.E WITH: ~.f'H.ill TEXAS STILTE C01~L.8GE FOH ',"FOM:El~ REVERBJ~-FLOi:J NIODIFIED OSTWALD TYPE VISCQMJ3;T1~H

This instrument originally vta.s designed for use with

. opaque liquids .and extremely high molecular YJeight fluids,

wherein upward .flow of the fluid through the capillary under

pressure of an inert gas would prove more satisfactory than

downward flow. The instrument is shovm. in Figure 1, which

is attached to the end of this section.

The operation or this viscometer is described. briefly

as follows: The experimental arrangement of the viscometer

is shown in Figure 2 which appears at the close of this sec­

tion. The thermostat comprises a battery jar fitted with a

electric heating and ice-water cooling coils, ano ·a relay.: .

type thermoregulator. .An eJi.-tremely important variable .factor

in viscosity measurement is temperature control, and temper­

ature variations not exceeding about 0.05°G. must be assured.

22

Seafol~d grade nitrogen (liir Reduction Corn_9.) containing

not more than 0.01 r;e:r."' cent o::rygen was used throughout the

work. IJ.ne nitrogen was passed through a. gas \vasher containing

alkaline pyrogallol to remove the la.st traces of' oxygen.

The viscometer assembly \Vas placed on the 125 ml. I:.:rlen•

meyer flask containing the cotton dispersion. Nitrogen v1as

passed through the side arm. anc1 flushed through the flask and

out the viscometer until the Zimmerman Fog trap indicated that

no oxygen was present.

The viscometer then was introduced into the solution up

to the etched mark. · The viscometer assembly was placed in

the constant temperature bath controlled at 25 ! 0.05°0. and

aligned by mea:ns of a level .fitted to top of the viscometer.

~ T-tube was connected across the top of the viscometer and

nitrogen was passed through it •

Nitrogen was introduced into the .flask at a predetermined

pressure (as determined by means of a water barostat,) and

the pressure was measured on a manometer.

Pressure was applied on the surface of the dispersion

and the efflux time .fo.r each of the tv1o bulbs was recorded.

17S -~

290 mmo

23

Level

1.5 - )eO mm. IoDo

~

a&J.b I 2 (2o9-3.l mlo)

~ ~

Bulb #1

\

Figure :L. - 'l'SCW KODD, !ED

CS'l'WA1J) v lSCCUE'lm

S mm. IoDo

•-- l2S ml. Bz:-lenmeyer Flask

/

Ha

l_ D

---- L Nitrogen

I

I I I I

A t _,, r ... ~ .... I

nrc ' II I c I 0

0

0

0

0

/ ." Figure 2. Experimental arrangement o:f, the TSCW Viscometere

· :·;·,A. Viscoi)leter Assembly B. Constant Temperature Bath c. Water Karostat D. Water Monometer E. Zimmerman Fog ~'rap

Nitrogen r« •

~

25

c. CALIBRATION OF TSCW REVIGHSB FROI~ ----------- -- ----I!fODIFJ:ED OSTWALD VI8CO!{J:ETI~R

1. DETEBMINATION OF EFFLUX VOLtr£!E

The capillary of the viscometer was filled with dis­

tilled water up to the etch mark a.t the bottom. of the l.ower

bulb. This water was transferred to a. weighing bottle and

the tveight recorded~ The viseom;eter nel..'t \Vas filled with

distilled water to the etch mark between the bulbs. This

water was transferred to a weighing bottle and the weight

recorded. The weight of water held in the capillary was

subtracted~ and .from the density at the temperature of ma­

nipulation, the volume of the lower bulb vias computed. Sim­

ilarly the volume of the upper bulb was computed.

The results of these measurements are summarized in

Table II, which follows this section of the report.

2. DETERtviiN.ATION OF C.APILLlffiY RADIUS

Distilled mercury· \Vas drawn into the capillary of the

viscometer. The length o.r the column of mercury was measured

to the nearest 0.01 em. and the mercury \~las weighed to the

nearest 0.0001 gm.. This was repeated six times with each

viscometer. The radius was calculated .from the equation:

where

w .r = <1r e h

:;2 )

11 = weight of mercury, gra.

e = density of mercury, gm. em.. --3

h = height or mercury •. em .•

26

rhese result-s are given in Table III. The precision o.f

these determinations ·was about 0 .• 02 per cent.

3• · CALI:SRATIG}i OF WliJ:TE IiJIIlfERAL OILS USED li<OR C.ALIBR.AT!li.G TSCW REVERSE-FLOW MODIFIED OSTVlALD VISCOlVIETERS

The modified Ostwald viscometer is an instrument which

measures relative viscosity. All viscosity measurements are

determined in instruments which have been calibrated against

oils of known viscosity. These calibrating oils are assay-ed

i.n master viscometers upon which the variable factors in the

Poiseulle equation are known with a high degree of precision.

For this work a series of white mineral oils \Vas used.

These oils were highly refined gas oil fraction.s which \vere

water white. The viscosity of these oils was determined at + 0

25 - 0.05 C. using calibrated Oannon-Fenske viscometers. These

oils then in turn were used to calibrate the TSCW reverse-flow

modified Ostwald viseometers.

The viscosity of these oils was determined using two

different viscometers, with triplicate efflux times recorded

27 for each viscometer. The kinematic vi-scosity waa calculated

using the following equation:

_.,/ = y{"' K 25" C/t • • •. •!Z

These results are given in Table IV. The precision of these

determinations wa.s within O¥tl per cent.

28

DETEID;1INATIOI\r 0]' EFFLUJ{ VOLUM:E~ OF TSCW BJ"!;V:EHSE-. FLOVl 1£0DIFIED OSr.l'W ii.LD VISCOI11IETJ~HS

VISCOME~ER l~MBER

150-Al 166-Al 186-Al 111~-Al 148-Al

Volume, ml., I ;5.0100 ;.0315 ;.0164 3.0117 3.0027 :;.0042 ;.00?2 3.0067 2.9490 3.134-6 2.8954 2.9896 2~9711 2.9760 2.9650 2.9523 2.9687 2.9461 3.0274 3.1532 3.0060 2.9918 3.0100 2.98?9 3.0047 2.9844 3.0391 2.9694 3.0218 2.8950

.Average 2.9753 }.0046 2.9866 2.9956 3.0258 Ave. Dev. ()I 1.0 0.6 0.8 0.8 2.6 A>

Volume, ml., II 3.0475 2.9838 2.9065 3.0202 2.971? 3.0105 3.0008 2.9301 3.0.580 2.6953 3.1518 2.9819 2.9559 3.0101 3.0187 3.071? 3.0097 3.0016 2.9859 2.?060 3.0340 2.8798 2.94-46 2.9441 2.7937 3.0258 2.9850 2.9732 3.0061 2.9676

Average 3.0569 2.9735 2.9519 3.0055 2,8588 Ave. Dev. ol 1.3 1.6 0.8 0.9 4J!i4 /0

I. indicates lower bulb

II. indicates upper bulb

29

Viscometer Weight of Volume Of Length of Radius of 1lwn.ber Mercury, "'~ercury .);!.. . . . ' Mercury- Capillary

I!l!n • 3 Ool'Ultll'l,

gm. nun •. mm.

_:, ,.

,·-:i

50 . ..,Al 0.14-.59 10.77 5:?.l) 0.254

0.1284 9·47 46.6 0.254

O.lLf.ll 1.0.41 51.4 0 .254·

66-Ji.l 0·2785 20.55 57··8 0.3;56

0 .• 2630 19-.l~l 5lk.7 0.336

0.2170 16,01 45.1 0.336

as-1u 0.3791 27.98 4?.9 0.431

o •. 3S02 28.06 4-8.0 0.431

0 .• 316:? 23.35 40.0 O.LI-31

1.1.5-Al o.6?9l 50.1:3 48.8 0.571

0.4564 33.69 32.8 0.5'?1

0.5?35 42.3? 41.6 0 • .569

~48-Al 0.2848 21.02 12.1 0.742

O.L~350 32.11 18 • .5 O,?LJ-2

0.?4·2? 54·.82 32.0 0.'738

OIL

Brillol White Mineral Oil

Kremol. No. ?O

Kremo1 Ho. 90

<.;tr~1i:_.:ht

no. 125

Ramol No. 185

Ramo1 No. 350

......,T1.....,\.BiMiiiiiiL,....E IV

CALIBRATION OF WHITE MINERAL OILS USING ·CALIBRATED CA:NNOlT-FENSKE VISCOMETERS

VISCOMETER VISCOMETER TIMEt KI!TEftB:ATIO NU:MBER lc/25°0 (See/es) SECONDS VISCOSITY DErlSifi

OENTISTOI\ES

100/S63 3132 206.9 201.1 6.58 205.3

100/S84 3064 200.8 201.0 6.55 200.2

Ave. E;.$b 0.8025

J.OO/S63 3132 722.5 721.5 23.04 720.9

100/S84 3064 707.9 708.5 23.10 706.9

23.o? Ave. 0.8310

100/8159 1595 455-7 456.1 28.56 l.J-54.8

100/0155 1592 454.L{. 45LJ-.0 28.53 4-54.1

Ave. 20.54 0.8408

200/3141 793.1 270.0 269.8 33.83 270.3

200/8148 798.? 269.6 270.0 33.80 270.4

Ave. 33.31 0.8453

300/R648 400.3 672.0 672.2 167.9 6?0.0

300/R615 399.? 6?1.8 670.9 167.9 668.0

Ave. 157.9 0.8764

300/R64-8 400.3 672.? 6?0.9 16?.8 672.1

300/H615 399.7 671.5 669.2 167.7 6?0.1

.Ave. lb7 .7 0.8771

.ABSOJ.JUTE VISCOSITY CE~:rTIPOISES

5.26

19.17

24~00

28.58

14?.1

147.1

IV • R B S U L .T S l;,. N 1) D I S C U S S I 0 1~ -A. DISOUSSIOlii OJl CALIBRATION OF TSCW - -· -

1. COMI)UTATIONAIJ METHODS FOR DETERMiliiilG VISOO~ffiTER CONST~~TS

This viscometer can be operated by upward flow UL'lder

pressure of nitrogen gas,. or by downward flow under the

influence of gravity. For th.e discussion which follows, the

symbols to be used have been described in Table V, which is

attached to this section.

The calibrations have been made against previously

calibrated oils and the constants have been determined by

three independent methods: (a) by flow measurements using

oils of known viscosity and solving for H0 and C from tvvo

determinations of viscosity. (b) from flolv measurements

v1ith the value of H calculated using the follow·ing equation:

H=H -H =H -ht:> a o a .o'- •••• ·!Z.

and

H =

l n •••• •._2

31

.?2

where

h1 , h2 =height from botton and top of viscometer

bulb above liquid level in flask. em.

H = a_p1)lied hee.d, em. ( o.:f' v;ater). a

and (c) b:y utilization of physical measurements of factors

a.:ppearing in the l?oiseulle equation• The .following paragraphs

describe the results which have· bee11 obtained~

2 • DETEFJ,[INATION O~F' CON'STAl\fTS FROJ;;l FLOW Ml~Jl.SURIGMBiiT D.ATA

Tlte general equation :r·epresenting flow in this viscometer

is

•••• ·12.

and combining instru:m.ent ·and numerical constants

C(H ! e h )t a · o ,")0 ..... •.$::._

Both C and h0

may be computed from the <Jfflux times

using two calibrated oils at two different .. ~pplied pressures

as follows:

••••• g!_

and

c ::::: .... ·~

33

The results o:f this calibrational device are given in

Table VI, which is attached at the close of this seetion.

The driving head was calculated using equation 18 .from

the measurements of the h1 rutd h2 , for each· bulb of the

viscometer, correcting for the change in level of solution

in the Erlenmey~r.

The co11stan·o '!:Vas calculated :t:rom equation 20. The

results have the inherent weakness involved in the measure-

menta of h1 , h2 , h;s, h4 , which were measured on millimeter

paper and are easily subject; to one per cent ex'rOI... 1.I:hese

results are given in Table VII.

3. DETERMillATIOI\4 OF CONSTJJTT BY COMPUTATIOl~ FROM POISEULI1E ' G EQUATI0£1

The values o.f constants tor the TSCV'i Roverse-F'low

Modified Ostwald Viscometer have boen computed by direct

:measurement of the physical factors in the Poiseulle aqua-

tion, which follows

2-.... ·~ an.d

c .... -~ The values for V, the efflux volume, have been given

in Table II. Values o:f r, the capillary radius, he.ve been

determined, and are shovm in Table III. Values of~ capillary .

lenglth lt are shovm in Table VIII, whiell attached ·t;o this

section. The constant; a tor viscometel"S numbers 50'· \s6 .~ and. ·'

86 were 0.000720, 0.001992, 0.005L~2;s, respectively. The'se

results ""t'ere within fou:r.~ per c.ent of the constants p~eviously

calculated. The values of h0 measured anct calculated . .from

the calibrated oils were wi·thin ·three per cent.

The constants obtained :rrom the calibrated oils are the

most reliable and. were used in the work to be described la.ter.

These constants are given in Table VIII.

4. ACCtf.tlACY OF DET1~PtJ\1INATI01!8 OF VISCOMETJsR CONSTANTS i it DISCUSSIO~T OF EI{RORS

The results which have been obtained for viscosity con-·

stants by methods outlined i.n Section IV.A2 an.d IVA3 ,a_gree { '''

remarkably well. These values have been determined'by.: totally

different methods and the devi.ations do not exceed about tvto

per eent.

', ,.

·fhe sources of error in these determinations . are summa-

rized in the pax·agraphs which follow.

l. Loading errors are non~existon·t;; the viscorn.eter

must be accurately set at the etched mark, since a.ny variation

here affects the driving head.

2. Kinetic energy and end correction considerations with

the TSCW instrument are ideutical in character with those as-

35 sociated with the Cannon-F~nake in.strument.

:; • Drainage errors for both instrttments are the same,

since both instruments are similar in bulb ~a. capillary

construction.

4. Surface tension errors for the Cannon-Fenske and

TSGW instruments are identical for the reasons given in the

prece,ding ~ pa.ra~graph.

5. Variation in e.ff'eotive head at dif£erent temperatures

does not exist with the TSCW instrument, a inca a change in

volume of the solution in the system would have a negligible

effect.

6. Alignment of the TS<JiN instrument is very important.

A five-degree deviation from. the vertical intx·oduces ar1 ho 0

error of 0.4 per cent and a. 10 devir;rtion produces a 1.5

per cent error. Wllen the applied pressure is St"llallt these

ho errors are magnified. A special level has been designed

for this viscometer in OJ."der to minimize these alignment

errors.

?. The value H0 values are a function of the viscosity

of the fluid and the applied head. So long as the difference

between the applied head and H0 in reverse flow is greater -2 than four gm. em. , the error is kept to within about 0.5

per cent. These errors are negligible in downward .flo·;.'/ even

36

when there is an applied head. This l(;1tter situation is the

case with the Cannon-Fenske instrument.

_.T_AB_L_E_1 X

DESCRIPTION OF SYMBOLS USED IN THE DEVELOPME!~T OF VISOOMET.RIO EQUATIONS

J . I

Terms ··1 \ Symbols . l '. Equat~~:s I Un:l.ta --

Capillar.y length

Capillary radius

Concentration

Constant viscometer

Density

Fluidity

Gravitational const~~t

Head, applied

Head., fluid

Haad 1 net

Height, fluid column

Height

Pressure Shear rate

Time

Viscosity, absolute

Viscosity, intrinsic

Viscosity, kinematic

Viscosity, reduced

Viscosity, relative

Viscosity, solvent

Viscosity, Specific

Volume

l

r

c

.G

e ro g

Ha.

Ho

H

ho

hl'} h2' h3' h4' p

dtl/dx

t

7 [1)

-V

fsp/C

?(r

?o 7( sp

v

...... -·-----

¢ = 1/-y

---..............

Ho = Q ho

H ~: Ila +: Ho

,..... .... ---

P=e.Hg

du/ d::t = av /3 rr r:3 t

---'? = '71 r 4

1:"t/81V

[(J = ;~ 0[log '(sp/C]

V:: ~e .........

'fr::: r; r 0

1 sp = Plpo -1

em •

em.

g;m.. sol./lOOml, sol v.

............

gm.., em. -3

-1 ) em. sec. g,m.. (rhea, :

em. sec. """"2

grn. cm.-2

gm. cm.-2

f,;IIl• cm.-.2

em.

.. -2 o.ynes em.

em.

so.'"' •l Q\,i.

see.

-l -l( . ) • em. sec. po~se

---ern. 2sec. -l (stokes)

gm.

... .......

----1 -1 ( . ) em. sec. po~se

7. em.=>

Direction of

Flow

Upv-Jard

Downviavd

UpwB.l'd

Downward

Up1-1ard

Downward

Upward

Downward

Upviard

Downward

..,.TA.,..B....,IB...,.t VI

CALIBRATION OF TSC\i' REVERSE! lifLot-1 f.iODIF'IED OBTtifALD Vl8C01'lli1'l!ER

BY FLOt-1 r1EASURE!~IENTS

All measurernent at 2.5° o.

OBSERVED VArnES CALCULATED VALUES Applied Eff'1ux Time, Absol.ute

Head (Rise) I I II · Viscosity, Ha em.. H2o Sec. Sec. Cent1po1ses

ho, . Dens1ty, 3 1 em. H20.· gm. em.- I 1. 'II

-1 Cent1po1.aas see.

x I :rz VISCOI.ffi!TER NO. 86-Al

20.00

23.84

436 • .3 686~9

29.$.1 391.9

(Gravity) 1 301•01242•1

21.40

24.77

469.31689.0

344.8 ~.$0.7 (G~avity} I 376.2 1301.2

25.70 1840.8 1082.8

33.28 1541.7 632.2

{Gravit.1) l 98o.s 789.7

33.~0 353.2 410.9

28.87 440.2 532.8

(Gravity) I 66?-~:41538>(. 7 -

33.11

27.73

tL339 .1.11591.8

p..8l~.OI2275.8

(Gravity) l2346oti 1893.1

19.17 0.8310

lw9.17 o.8)lo

24.oo o.84o8

24.00 o.S4o8

VISCO!-lETER 1~0 •. 66-Al

24.00 o.84o8

24.00 o.84o8

VIS COH1:!~Jff~R NO. 50-Al

.5~26 o.Bo2S

.5.26 o.Bo25

19.17 o.831o

9.17 o.831o

r

l4•4~ll7•92

14!'o2117~41. I e.oo5471 1o.oo5472

:Ut-•37117•90

13.89 l 1.7 •38 1 o.ooS476 IC>.oo$461

14.281'17.90

14.o6117.4o I o.oo2o78 1o.oo2o83

14·57\18.23

14.11117.551 o.ooo695~ o.ooo6927:

1.5.11\18.36

14.1211B.1o I o.oo6966 1o.ooo674o

..-TAB~LE-..• m · CALIBRATION OF TSCW REVERSE FLO. W ~IODIFIED OSTl4J:ALD VISCOMETER BY CALCULATION ' .. '

OBSERVED VALUES Di- Applied Eff~ux Time~ Abso-

rEdiion Head, lute Vis-of (Rise) I II cosity,

Flow Ha,·cm. See. Sec. Centi• H20 poises

Upward 24·77 344·6 14.50.7 24·00

Fall 376.3 301.3 24.00

UpwB.l'd 33.28 .541.7 632.2 24.00.'

Fal~ 98o.s 789.7. 24.00 ',

Upward 33.10 3.53.2 410.9 ;>.26

Fall 667.4 538.7 5.26

I =,Lower bulb; II = Upper bulb

All measurement at 250 c.

OALClJLATED VALUES

Measured Height, om• Density I II gm.am.-3 ~ ''b. h3 h4 ,,.1.·'13;

VISGOHl!;TER NO. JH-"?"-A:L . o.tl408 12.6.5 15.35 1.6.30 :L9.00

o.a4o8

VISCOl•1ETER NO. 66-Al ...

o.a4o8 · 12.60 15•30 16.20 18.90

0.8408

VISCOMETER N0 •.. 50-Al

o.ao25 12.80 1.5.50 16.45 :L9.lS

0.802.5

:.;

Driving · .. -Read

2· ··-gm.cru.

I II

'• · .. ''·

J.2.9b J.O.Otl

11.66 1.4.61 '

' :.. . ,.

21•.53 18.$0

11.69 14•72

21.69 18.76

1.1..32 14.2e

-· --Constant.

I II

' .·. .. ..

0.005371 :>_.00_5262 .: .

o.oo5469 o.oq5~S3 .. ,;

.: ... :·.:·::··

,., '.

. . ' ' _",.

o;.oo2ose 0.0020$2

·0.002094 p.002064

o.ooo6871 0.0006829

o.ooo6968 o.ooo68,58

\.}.! '-.()

'

Visco- Efflux Volume, meter em..3 Number I II

50-AJ. 2.9753 3e0.$69

66-Al 3o0048 2.9735

86-Al 2.9866 2.9519

11.5-Al 2.9956 3·0055 J.48-AJ. 3e0258 2.8588

-

""'"""'TA ...... B_m_ !Ill S~il1ARY OF ·qALmRATIONAL VALUES AND OONsr.rANTS FOR

RETh"RSE-FLOt-1 l40DIFmD OS'n'!ALD VISCOl-1ETERS .

~\ a Height of Fluid Column,h0 Viscomete~ Oonstant1 ~ Radius~ Rise · Fall H mm. em. I II I II. I II.

0.254 7·9 14·57 1.8.23 J.4.:tl. 1.7.80 o.ooo6963 o.ooo6927

0.336 8.3 J.4.28 17.90 :t.4.o6 17.40 0.002078 0.002083

0.431 8.2 14-41 17.91 14.02 17.39 o.oo5471 0.005472

o.57o 0.741 14·44 18.o8 14·32 1.8.02 Q.047l.l o.o4622

Shear Rat.e Constantb

I II

1.54600 1.58300

67200 66?00

31600 31800

1.3700 13700 •;(

6300 6,300

'------~-~-____ ____. ___ ~-

~--..-..._ __ ,........._ ___ ·~·-------'---··--~~-~ . ..___.__..._.__

"----~----~---

a determined expe~fmentally with calibrated oils

- calculated

+:-0

4-1

B'. DETERMINATION OF VISCOSITY OF _c ..... o_T_'J!,_Or_r DISPERSIO}t - - ......,_

IN CUPRIETHYLENE DIJill~INE

The viscosities or dispersions o£ 0.1, 0.2, and 0.3

weight per cent cotton in cupriethylene diamine were de­

termined using the ABTM Burette viscometer previously de­

scribed. Dispersions were mad.e using the mechanical shaker.

The results of these determinations are sho·wn in Tables

IX, X, and XI, and are plotted on Figttre 3. The l1.STM instru­

ment permits determinations at .four different rates of sl1ear,

enabling results to be extrapolated on a log-log plot to 500

reciprocal seconds, which is a standard reporting device.

2 • RESULTS USING lJ.'liE TSCW Rl~V:e.:HSE-FLOW MODIFIED OSTWALD VIf3COMI~TER

Viscosity determinations similarly were made on the same

dispersions by means of the TSCW instrumen-t devised for ·bhis

study. Through the upward flow of t;he fluid through two bulbs,

by means of applied pressure of nitrogen gas, and by means of

downward flow through two bulbs und.er gravity headt viscosities

were computed for four different rates of shear. These values

are shown on Tables XII, XIII, and JtiV, ~d are plotted on

Figure 3. No apparent increase in fluidity v.ras observed upon

42

repeated determinations. This is excellent evid.ance ·that

oxidation has been excluo.ed with this i.nsJcrumen·t. Viscosity

measurements were made first using the .ASTr~ procedure then

using the TSCW instrument, then again with the ASTM procedure,

with no apparent chedlge in viscosi-ty as indicated in Table

XI.

Fluidities determined using the TSClV instrument were

in very close agreement with, but consistently higher ·than

those obtaj~ned using the ASTM inst:r:ument. This is the sam.e

as say'ing that viscosities determined using the TSCW instru-

ment were consistently lower than those obtained using the

1\STM Burette instrument.

The possibility exists that the somewhat higher viscosi­

ties obtained with the ABTM instrument e~e due to the kinetic

energy and e11d corrections which prevail v:ith an orifice-type

instrument •

.3. COMPARISON OF THI; IIfTH.Il\f£~IC VISCOSITY OF DISPBRSION·s BY THE ASTM JhlTD TSCW INBIJ.'B.tJI;~iENTS

The intrinsic.:·, viscosity of the dispersions of cotton

in cupriethylene diamine were determined by plotting the

logarithm of reduced viscosities as ordinates against con­

centrations as abscissas. Extrapolation to zero concentra-

tion of the straight lines obtained by the two instruments

produced values of 27.8 and . 25.9, res:pec·ti vely, .for the AS Tid

4,3

and.· TSCW methods. ["b.ese ·data. are tabuled;ed on Table XV and

are plotted on Figure 4. The values differ by a.'Qout seven

per cent.

T.lillLE .!!

THE VISCOSITY (FLUIDITY) OF A 0.1 \fuiGHT PER CENT DISPERSION 0Ii' 0 PAYM.ASTER. 54-192 COTTOn IN CUPRIETHYLENE DiaMINE AT 25 C • AS DETERMINED USI!iG l\ST!t! TYPE BURETTE

Viscometer Ring Standard

Observation 5 10 15 20 Fluidi, rl1.es (a. 500-l

Burette No. 52-67-11

Efflux time. Sec. 102.2 128.3 165-8 232.3 Fluidity Constant 2278 2750 3419 4534 Fluidity, rhes (a) 22.50 21.62 20 •. 73 19.60 Shear Rate Const~t 14800 14800 14800 14800 Shear Rate, Sec.- ll.J-?9 1158 895 645

18.65 Burette No. 11·7-6?-5

L.;fflux time, Sec. 10~.7 121.9 158.6 232.6 Fluidity Constant 2291 274-7 3426 4571 Fluidity rhes (a) 22.-77 22.'7~ 21.76 19.73 Shear Rate Constant 14900 14900 14900 14900 Shear Rate, See+-1 1466 1222 940 642

18.80

(a) Kinetic correction included

18.72

f

TABLE ~

THE VISCOSITY (FLUIDITY) OF A 0,:2 WEIGHT PER CEUT DISPERSION OF PAY.MASTEH 5lt-l92 CO'J:TON IN CUPHIETilYLEI\fE Dl.A .. l"JIIN:'"ili AT 25 ° C. AS DETEPill1Il-TED USII\fG JlS11J:vi TYJ?E BU11ETTE

Observation

Efflux time, Bee Fluidity Constant Fluidity rhes (a) Shear Rate Constant Shear Rate, Sec.-1

Efflux time, Sec. Fluidity Constant Fluidity rhes (a) Shear Rate Consty.nt Shear .Rate Sec.-

Viscometer Ring

5 J,lO I. 15

Burette :No. .t~B--67-5

258.6 2300

8.88 14900

576

330.5 2749

8.32 14900

452

LJ-_54 .• 3 3410

7.51 14900

328 Burette Ho. 53-67-11

262.9 329.4 l~53.8 2276 2740 3390

8.67 8.30 7-49 14800 14800 14·800

566 451 328

(a) Kinetic Energy correction included

1 20

674.2 4534

6.?2 llf·900

221

673.9 45?7

6.65 14800

221

Standard Fluidit:y rhes (a.)500-l

8.56

8.52 8.54

~ \J1

TID~ VIBCOSITY (FLUIDITY) OF J-. 0 •3 VfEIGHT ___ CLiNT DISPERSION 01!., l'l~Yl~IAE/.l'.ER 5Lt-l92 OOTTOti IU CUP1\:IETJ:Il~EH1TI DIAMn~E AT -25 ° C •, AS D1nTERl\1INJ!iD USING -TYI::E BUltETi'E

Viscometer Ring Sta.nde..rd. Observation 5 .10 15 20 .. F1u.idity _1 :w nes(a)500

Burette llo. 48'""'68-5; Solution A

Efflux time , sec. Fluidity Constant Fluidity, rhea (a) Shear· Rate ,constant Shear Rate,Sec ..... l·

183·3 790·.

4·.29 673500

36+

248.;; 954

;; .. 84 67300

2?l

-350.4 1184

:;.;sa 6?:>00

192

550.8 1575

2.8 6?300.

122

Burette No. 45-68-L~; Solution-1

Efflux _time, Sec • , 187.8 Fluid.i ty constant. 800 Fluidity rhes (a) 4·.26 Shear Rate ,Const~t 6?400 Shear Ratet Sec.-J. 358

252.4 950

3-76 67400

217

346.0 1182

3.42 .67400

19Li·

5/J..7 a ';J. ,1

1577 2.90

67400 124

Burette No. 49..-68-8; Solution B

Efflux time,. Sec 191.2 F~uidity'Constant ?9? Fluidity rhes (a) 4.1? She_ ar Rat_.e Constant.· 67300 Shear Rate, Sec. -l 353

25Lf-•9 . 946 ' 3.61

67'300 265

(a.) Kinetic energy correction included

366.1 ll94

. 3;27 67300

184

569 .LJ. 1584

2.78 67300

118

4.81

L~.80

I

I

oiiiiiiliTA.......,B ...... IEiiiillf XII

THE VISCOSITI' (FLUIDITY) OF A 0.1 WEIGHT PER CENT DISPERSIOlf OF PAY~lASTER .$4-192 COTTON IN CUPRm,THYIENE DIAMDlE AT 2..$0 0. AS DETERMINED USING THE TSCti REVERSE-FL0\11] 1-lODIFIED OSTWALD

V:tSCOl<IE'l!ER

Solution and T~eatment Factgrs

Viscomete~ No. 50-Al . Viscosity .constant {I) 0-.0006963 Viscosity Constant(.II) o.0006927. Shear Rate Constant (I) 154600 Shear Rate Constan.t(II) 158)00 Concentration, gma. ootton{lOO ml. solvent

h (Rise) I hg . (R1ae) II h (Fal.l) I ~g {Fal.l). II oonsity, gm.

o.1

lh•57 1.8.23· J.4.ll 17 80

cnt. -3 l. o048

S&~~LE DESIGNATION SA~WLE DESIGNATION lJle as uremen t A . (Rise} A (Fall) B (RS:ae) . B (Fall.)

Bulb I Bulb Il Bulb I Bulb I_l Bulb ! Bulb II Bulb I Bu.lb II '.

Applied·Head~ Hat ~~. H2o 40.30 40 • .30 40.20 40.20

Gravity Head, H0

, em. H2o ~.5.28 19.12 ll-,~..ao 18.68 15.28 19.1.2 14.80 18.68

Net Driving Head., em. H2o 2$.02 21.18 J.4.8o 18.68 24.92 21.08 ~4.80 18.68

Efflux Tinte, sec. 281.2 342.0 p41.5 422.8 278.1 340.3" p28.ij 403~2

Absolute Viscosity, 4.89 centipoise a $.00 s.s1 5.-47. 4.84> if .• 96 5.42 5~21

Fluidity, rhes 20.47 20.00 17.93 J..8.25 20.69 20.19 18.4!5 :t9~23

She~ Rata, sec. -1 549 462 ~85 374 $5;) 4'6.5 292 392

Fluidity @ SOO sec. -1' (20.05) ,.

(20.07) ,, . ~- ~

,._, •' -

-,

_.v--J :.--

- --~-·-·

'fABlE XIII

THE VISCOSI'l'Y (FLUIDITY) OF A Oa2 vlEIGHT PER CENT DISPERSION OF PAY!-1ASTER 54•192 COTTON l:N CUPR:rETHY!ENE DIAI~INE AT 2$0C. AS DETERMINED USING THE TSCW REVERSE-FLOW t-10DIFIED OST\iALD

VISCOliETER

Solution end Treatment Factors

Viscometer· No.· 66~Al Viscosit.y Constant (I) 0.002078 Viscosity. Constant(II) 0.,00208.3 Shear Rate Constant (I) 67200

h (Rise) I 14.28 hg (Rise) l;I 17.90 h · (Fall.) I 14.06 hg (lral~) II l7.hO · Density, gm. em. -3 1.048 Sheal." Rate Oonstant(II) 66500

Concentration, gms. cotton/100 ml• solvent 0.2

l-ieasurement

Applied Head, H4

, em. H2o

Gravity Head, H0

, em. H2o

Net Driving Head~ em. H2o

Errlux Time, sec.

Absolute Viscosity~ centipoises

Fl.uidi ty • rhas

Shear Rate 1 sec. -1

Fluidity@ 500 sac. -1

SAl-vp:r;g~_:QTI;R_I_Q!IA'rlQli[~-------------1 ~-~~---·---~· __ SJUJJFIE- _OOSIG).1ATTON

Bu~:~-~i~~{~~-J·B:~~1f~!ib- I;r~ll~:-~i~f;~ib __ Ili_Bul~- ~F~!ib II 40.95 . 40~9.5

·14·97 18.78 l 14·73 14·73 I .

25.98 . 22.~7 ·. 18.22 ·18.22

256.4 < 318 • .$ 68.7 llt26. 7

13.84 14-70 17.40 16.20

7·23 6.80 5·15 6.18

)262 1209, 11~8 1156 I

I (8.71)

1m VISOOSIU . (i~l~UDJ::t~) OF A Oe) lN'E!OlfJ: OF PAY')IAS'J!ER .SIJ•l:92 ~~1'TO!f XN Otr:PH.D!~l!m•J

~""'_·~_._m_.. .'!'.' ""~. ·~~')''! ¥":!_"_"*'''~.~.ttt. -~Z'\'ld ~-~~~t~~ ,fi;:t ~~~~y~;·t~"1 : : ~]".'~11 1!t1'1~~ AT 2$ ·C.

Ml l:rET.ERMIISD ll!:1I~'Q lJ~~~~ .:~u: ii.i!:'Y."'-~i'n.:.~.'~~~ t,)£i~~A!J;) · 'V:U.iCO~iA~EB

Vise~ tal'· ~io. 86-&ll Viscosity Oonstan~ (I) n.0$411 Viacos1t," Const:a~J.·t{I'I) o.OSZt72 Sbtaar Rate Col1St&1t (I) 31~10 SbeEtr nate Const~t(II) )l.&ltl . . . Canoontration. ena• e:ott~l/100 ntl:. tfCl:t'Oll:t·

tin&aW?Ol1lent

Applied Head,. II4

, Cil•· H2o

Grnvity Hf:}ttd; H0

$ ~. B2

<.l

tlat Dl'l'iVing Head, elm.• H2o

Ef.flux Thue11 sec.

Absolute Viscosity# eentipr;1ses

Fluid!. ty ~ l~hes

Shes!' Ratt:-,., sec. -1

I1-:luit11ty ;;oo sec. •l

41.00 ~ 1 ft~--·00

'l$ .• 10 1~ ..... ,. ....... O•f7

~- "'""'f'ti I ......... -1 ~,:,-~'7~ e.:<.!•t::~

4')~a ~ I..,~J.,. It ~-70.,;J! ~~··'f··~

"'}"""" ·~. "i,-·. ,Ji:! • 4 .1;

~ i'\t)'""" .;} ··\,.~~;"_:-:;

136

"l.·i!: ""~l .. ::>~•b~

2-oU(}~~i

106

( ,. .:'" ··~ -~ f..J, .v-e.::. J

·~~- 1' ·4'l.;. ~~-- 'i.;j

~/tO

J'-*A t;,. ?t~.:;

1~.$-30

12-.Zt~;.~f

!$6•2

ltJ.22

1-~ 1-t: &~0·4~

. ?8.4 1YT

"H_._t.,..~_. ~ ~·v-11• -14·1~1 17-01 .... ·:! ·x- ·_·.! ~ e,m,. . .· . ·•04u

:;J$.2 ~~;'1!,., a l,,~t:.Q-.;

•:tOft

{ h . t:1? ~l "\h)f. flb-"'V,!

<:.)3

ss.z

'l.!i -~~ ... .~.'4><""'-'

a1.3

"""'----------------------------...~o~~ ... -~-----..... -----"'""---'"""'--'"""""·~"i'~·· ... 'R-$111110!--110il'$-.. 1111oWi ... A~-....... ;>o~-'::&""."''"""~f>li>li! ... OEl"':""'""'~~~~-"tJ iMlFl.R~ ... ! 4 IL It .__Ad rJIRJ' --~: t -?J

50

TABLE XV ~ ........... -

SPECIFIC AND REDUCED VISCOSITIES OBTAIIfJz;D FOH 0.1 0, 2 JUTIJ 0 •; OElfT OOTTON-CUPRI1GT1i-:rLIGlf!& . DIJlMINE DIS1~'ERSI01i8 fJY ASTM BUR:EiT~1E

Al~D. TSCW REVERSJlJ ... FLOW M1~THODS

METHOD OOllfJJtJiiTRATION, ~iLUIDITY, SPECIFIC REDUCED II~THII'iSIC per cent {¢) rhes VISCOS!l_l"~Y, VISCOSITY., VISCOSITY

sp sp/c

ASTM Burette Q71 .:;; 4.72 17.17 57.2

0.2 8.56 9.01 45.0

0.1 18.?2 3.58 35·8 27.8

TSCW o.; 4.82 16.80 56.0 Reverse-Flovv 0.2 8.71 8.85 4.14 •• 2

0.1 20.06 3.28. 32.8 25.9

Cll <V

..cl J:..t

>; 8 H Q H p H ~

10 ~j .. ~ _.::; -, [3 : .._ 1 2 -~ ... ;. --~

I I I I I I I I I I 1 I . 1 i t·;

.8 ___ _

-- ---· ·----6. --

5---L~--· 1 __ :~_L_-:-::_::·-~: ,-_~L~ __ ··---- - +~-- ~-·- --

t. ·---·---·- -----:------ ...... : .. - w

4

... -3----

2(29) __ _

10

~ . . ·-. ; . . . - .. ; .:. :

------+------· --. ·----

. l

l.-- ··-- •.. ·-· --·· ...

~0.06

.. 7-~--:.:.-f.

!

200 300 400 500

. t ..... ~- ·-;··-i·· ~:· + -~ I

~~ ,------;~-r-~-- --~ f I

l·· i ··:! .

. i l f .. , ; l .:;~·:t::~~---F

l : .. :

' 0 .ASTM Method · · 0 Tscw· Method

! ;

I. I .l ' •·· I

700 SHEAR

1000(100) -12000(200) RATE, seconds

300 400 500 700

Figure 3.- Plot of Fluidity against Rate of Shear for the determination of the Fluidity at a Shear Rate of 500 sec.-1 for 0.1, 0.2 and 0.3% cotton in cupriethy1ene diamine by the ASTM and TSCW method.

\J1 l--1

~0

--~- -.-----r--~~---- . ; . 1 . :

.. : .. -· l . - .. i .

. ---~--· ~:_1_~---~----· -. - 52 ..... ! .

l . ••--T--·- --r---------,.--------r---....;.·~·---P--~--

_. Z9 __

60

.50

(.) 40

' Pi' Ol

~· E-t H

~ (~ 30 0 .. H

27.9

-.20-.

0.1

-i . -· l f ; . I ..

I .

0.2

' .·I -7-~----~--·-t··- .. ~--~· +

. t l -.

I

CONDENTRATION, PER CENT

Figure 4, Plot of the logarithm of the reduced viscosity agair cotton concentration in cuprietbylene diamine·for the determine: of the intrinsic viscosity by bo-:;J,~ the ASTM, (I) and TSCW (II) methods. ·

VI.. S U M ~i 1\ R Y

The viscosity of liquids · is a property vfhich can be

measured with an e:h."'tremely high deg~ae of precision. This

fact has been recognized for a considerable lenc:ith of time,

and he.s hastened the exploitation of the d.evelo};ilment of

high polymers - substances which are rather indifferent to

ma.ny chemical and physical measurament tech11iques because

of their great complexity and relative luclt of reactivity.

This thesis deals \Vith the s.da11t.e .. tion of viscosity measure­

ment technique .involving a forL1. of the Ostvnud u-t;ube for

application to dispersions of cellulose in cuprieth~y·lene

diamine. In this particular· in.stance tv1o £actors are re­

quired to be controlled: (a) the rate of. shear must be

established. for each viscosity :measu:r.:~ement;, because of the

a_ppare11.t non .. Nev.rtonian behavior of the dispersion system

cellulose-cuprietbylene diamine; and. (b) O:M:Y"gen must be

eJccluded from the determination because of the extreme serl­

sitivity of these higb. molecular wei[!;ht dispersions. In

additi9n, it is possible to utilize ·the unique characteris­

tic of this viscometer in terr11s of the elilnination of' all

ltinetic energy end end effects from the measurements.

·Viscosity is interrelated to molecular weight; both

of these properties are interrelated with the strength or cellulose fibers 1 yarns, and fabric. A number of disperse

53

54

systems for determining the viscosity of cellulose are in

eur:rent use. The most comm{)llly used method invol vea the

determination of the viscosity of cellulose i11 cupranunonium

hydroxide or cupriethylene diamine dispersion. The greatest

problem encounterecl ·with these- dispersions is that the cellu-

lose is readily degraded by atmospheric oxygen evan in traces.

In this investigation a reverse-flow single arm. viscometer

operating under an atmosphere o£ nitrogen h€tS been d_evised.'

This instrument can be manipulated simply eJld re..pid.ly under

circu.Jnstances wherein rate of shear can be varied over a \Vide

range; and oxygen can be excluded completely •

.. The viscosity of fluid in streamline, laminar, or viscous

flow is governed by a relationship first deduced experimentally

by Poiseulle, fu""ld later corroborated by vigorous mathemat·ical,

treatment from. Newton's law. It may be sho\:vn that this equa-

tion takes the following form

where fIe. is kinematic viscosity in stokes, a diffusion

2 -1 constant having the dimensional units of em. sec. •

Non-Newtonian behavior is characterized by variable

viscosity -- in other words, viscosity is a completely var-

iable function of rate of shear. The expression for rate.

of shear is the follo-.. qin;:;

56

the magnetic stirrer and ·the rnecllanioal shaker for two, four,

si::-c, eight, lOt 12, llt-, 16, 18• 20 1 22, and 2L~ hour intervals.

These data inclica.te that unc1egraded cellulose e:J{isting i.n bale

cot·ton is so high in molecular weight a.s to render 0.5 per ce11t

concentrations impractical !or routine evaluations.

The viscometars used in these laboratories were obtained

·with calibration certificates £rom the Ca.llnOl'l Instrument Com­

pan;r; State College, Penn.sylve.nia. This instrument originally

was de.signed for use with opaque liquids ru.ld extremely high

molecule.r weight fluids, wherein upwesd flO\V of the fluid.

through the eapilla.r'".t under pressure of an inert gas would

prove more satis.f ac·to:ry than do\v-.award flow.

The operation of this viscometer is described briefly as

follovfs; the viscometer assembly wcs~s :placed on the 125-ml.

Erlenmeyer .flask containint; the cotton dispersion. Nitrogen

was passed through the side arm. and flushed through tihe flask

and out the viscometer until the Zimmerman ll'og trap ind.icated

that no oxygen was present.

The viscometer then was introduced into the solution up

to the etched mark. The viscometer assembly was placed in a . + 0

constant temperature bath controlled at 25 - 0.05 C. e..11.d a-

ligned by means of a level fitted to top of the viscometer.

A T-tube wa.s connected across the top of the viscometer and

nitrogen was passed through it ..

57

. Nitrogen v.Jas introduced into the flask at; a r)redeterm.ined

pressure (as determined by means of a water barostat) and the

pressure was measured on a mru1ometer-. Prosst.tre wus applied

on the surface of the dispersion and the efflux time for each

o£ the two bulbs was recorded.

The volUt"lle of both bulbs v1as computeo. using stan<le..rclized

teolmiques for this determination. Also, the re.dius and length

of the capillary was determined by weiz;ht-volUille relationship.

The modified Ostwo.lC. viscometer is CL."l inctrument \Vhich

measures relative viscosity. All viscosity measurements oxe

determined in instruments which have been calibr~tied a~:;e.inst

oils of tnown viscosity. These calibrating oils arc e.ssayed

in master viscometers upon which the varis.ble fc.ctors in the

Poiseulle equation arc knovn1 y;ith a hi . .;h degree of precision.

For this work a series of whito mineral oils was used. 1'hese

oils vvere highly refined gct.s oil fractions ·~vhich were wate:rl

white. The viscosity of these oils was determined at 25 :!:

0.0,5°0. using calibrated Cannon-Fenske viscometcrs. These

oils then in turn VTere used to calibrate the Ti~c:.r~ reverse-

flow modified Ostwald viscome·ter.

This viscometer can be operated by upwci·c~. flo\~/ uno.er

pressure of nitrogen gas, or by c-:.ovr.o.\'Jard flow under the in­

fluence of gravity. The calibrations have been mcdc against

previously calibrated oils end the constants have been de­

termined by three independent methods: ( o.) by .flori measure-

58 merits using oils of known viscosity and sol vi:n;:; the H

0 c-md

C from two determinations of viscosity, (b) fr,ont flo·w measure­

ments with the value of H calculated using the· follov;i11g equa­

tions

and

H

H= IIa - -r l.J.o

hl - h2 = Ea + l n -

Ha + -hl e 112 e

and (c) by utilization of physical measurements· of factors

appearing in the Poiseulle equation.

The constants for viscorn.eters numbers 50, 66, and 86 v1ere

0.000720, 0.001992, and 0.005Ll-25, respectively. These r<~sults

were within four per cent of tl·:e constants previously calculated.

The values of h measured and calculated· from c·alibrated oils 0

w·ere within three per cent. The constonts obtained fro.n the

calibrated oils are the most reliable and vJere used. in th.e

work here described.

The viscosities of c.ispersions of 0.1, 0.2 and 0.3 tveight

per cent cotto:::. in cupriethylene c1.iarainc were d.e~ermineu using

the AST?.i Burette viscomcte:r: end the instrument ·devised r or tb.is

study. Throu.)l the upward .flow of the fluid through ·two b·ulbs,

by means of appliod pressure of nitroGen gas, and by means of

59

downvvard. flO\V through ·t;wo bulbs under gravity hea.d.t viscosi­

ties were computed for fow.~ di:Cferent rates of shear. No

apparent increa.ae in fluidity \?las observed. upon repeatied de­

terminations. This is excellent evidence th:;rb oxidation has

been excluded with these instruments. Viscosity measurements

vvere made first using the AS1"M procedure then using the T:SCW

instrum.ent ~ th·en again with the ASTrii procedure wi·!Jh no e~ppc.lrent

change in viscosity.

Fluidities determined using the TSCVl i.J.'""lstru.rnent were in

very close agreemen·t with, but consist;ently higher than those

obtained using ASTM instrument. s.rhis is the same as sayin[;

that viscosities dete.r.rn.ined using the TSOW instrument \ve.re

consistently lov;er than those obtained usinc; the AS~l'.M Buret;te

instrument. The ·possibility exists that the sornev;hat; h.iS}1er

viscosit-j.es obtained with the ASTl.I burette are due t;o the

kineti .. c energy and end. correct;ions which prevail with an

or;tetoo--type instrum.ent.

The intrinsic· viscosity of the d:lspersi.:Jns of cot;ton in

cupriethylene dia:mine were determined by plottin;; the logarithm

of reduced viscosities as ordinates e.gainr.;t concentrnti;.)ns as

abscissas. Extrapolation to zero concentration of the straight

·lines obtained. by the two instrumen·ts produced values of 27 .B

and 25.9, res:pec·t;ively, for the ASTM and. TSCW methods. These

values differ by about seven per cent.

VI. FUTUHE WOHK ·-The results of this study ind.icate that t;he moc1ified

Ostwald type viscometer can be adapted for use tvi th solu·tions

which are sensitive to oxidation, e..nd from ·which orc~gen must

be excluded. They also indicate that reverse flovr of fluid

upward through cc.tpillary and the efflux bulbs produce compu­

tational problems Vlhich are rather involved, and which p:t:-o­

bably v~ould. be likely to reduce the utility of the method •

.Accordingly the following areas £or future v1ork are indicated.

1. Work needs to be done to a.dapt this instrument to

downward ~,flow. This ~:vould permit repeate-d determinations of

efflux downward, until values of efflux time falling witihin

the desired limits of preci$ion were obtained.

2. As presently constructed, the instrument requires

many critical adjustments in order that viscosity de·terminations

are carried out under conditions identical with those prevailing

during calibration. In many instances these adjustments can be

made only with a low degree of precision.

3. The instrument as presently constituted is eXtremely

cumbersome, and its manipula-tion requires much de:xl:ierity on

the part of the operator. It is suc;gested that redesign. might

easily reduce ·the number of component parts involved, in this

v;ay providing greater ru_;gedness consistent with greater ease

60

61

of manipulation. Simplification of the instrument also j,.s

likely to invite wider adaptation ~md stru1dardizaticn of this

technique within the field.

4. Much work still needs to be done on ·the technique

o£ dispersion of cotton in cupri.ethylene <.liamine. A more

intense exploration of the depolymerization effects of varioun

types of mechanical vrorking of the cellulose durin~; dispersion

also is needed. In addition, considerable stut\y is needed to

establish the hlOSt satisfactory levels of concentration o£

native (lint) cotton end of degraded (spun, v1ov·en, and exposed)·

cotton for fluidity measurements.

l.

4.

5·

BIBLIOGRJi.PliY

Testing Material, Conuui·ttea D-13 t Dis ersions of Cf~llulose ]'ibers,

Ca.uno:n, M. R •. , Viscosity Measurements, Master Viscometer, Industrial and Engineering Chemistry, Jmalyt;icai Bdi tion •. 16 t 708 (1944) •. -Cannon, M. R., and Fenske, 1~1. R • ., Viscositz Measurements 1 Industrial and Engineering Chemistry, .l1.n£~lytical J~diJGioll, 10: 297 (1938). Conrad, c. M., Private Communications, April 19 (1955).

F. 1 1\!\ R ···1 ·!':'~ 1"\ ... D b· . .,..,, R nr V .... ens te, .t~1. • J.\. . aus, JE. .!t. , ana. annen rJ.. . .u..r;:, 1 • 'i~ • , l.s-cosit"l; Shee:tr Behavior of Tv.ro J:Ton-lrevrtonir;:n }'ol r.:ner-Blended Oils 2 Symposl.um on :Wlethods of JJeasuring -iscosity at High Rates of Sheax, ASTM Technical Publication No. 1117 page 3 (1949).

6. · Hesler, Lyle IE. , :E'ri vate Comraunication., July 22 ( 195 5) •

s.

10.

11.

•

Kemp, .A. R., anc1 Peters, H., Viscosity~1\~olecula.r Wei~:~;ht, of Hubber--CI.·.yo..:scoJ2i.c _. Deviation of Eu.bber Eoluti0n l'rom Raoul t 4 s Law, Industrial e.nd :u;.ngineering Chemistry, 2.2.; 1263 (1941). .

Staudinger, II. , and Heuer, Vv. , Uber Hochpol~el"e Ver­bindun:rJ"en - mitt. Uber das Zer:reissen d.erraden.molelu..1J.e des Polyst;yrols, BerJ.chte, 6(B: 1159 193Li .•

Straus, F. L., and Levy, R. M., Oupriethllene Diamine Di$ erse Viscosi t· of Cellulose, :J:·aper i 1rade Journe1, 114, No. ;;: :51 1:;~4 •

Thomas,. R. M. , Zimmer, J. 0., et a.l., Polybutenes ,ProE,­erties and Uses in I>etroleum Products," "Industrial end EngineerJ..ng ChenlJ..stry, 2,g: 299 (1940) •

Whi t\vell, John C. , and Sch\venlcer, Hobert li'. , De;,~radat;ion of Cel~ulose Du;in:? IYI~ch~ical P~9cessinr~ 1 J?c.rt III: A Co(tarJ.son of tne J~;valuaJ;J.on b VJ..scometr~c VIethods, Tex ile Research Journa 3: 17;, 1953

Zimmerm~1! VJ., Arbeit~ver~chrift~n zur Bestim..rnunrs d?r Dv.rchs~nnJ. ~t-ST)Ol:;op.er.J.sat~on. grao.e~ und. cler KUl)fervJ.sko-.§J. tat Von t:Jellulose, £,1elll.and. Text:~.lberJ.chte, 23: {13 (19'~2).

62