development of reverse-flow capillary viscometer of
TRANSCRIPT
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
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Page
1
6
13
13
13
l~)
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11.4~
15
15
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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 •
•
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· 4 • l1.GCUR.ACY O:El DJJ;TEftfl[IN.ATI c~·riS OJ? VISCOMETER
Page
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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.<l . . . 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