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Investigation of surface tension decrements of polymer solutions, particularly as a function of concentration and molecular weight of the dissolved polymer

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Investigation of surface tension decrements of polymer solutions, particularly as a function of concentration and molecular weight of the dissolved polymer

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Content INVESTIGATION OF SURFACE TENSION DECREM ENTS OF
POLYM ER SOLUTIONS, PARTICULARLY AS A FUNCTION
OF CONCENTRATION A N D M OLECULAR W EIGHT OF
THE DISSOLVED POLYM ER
A T h esis
P re s e n te d to
The F a c u lty o f th e School o f E n g in ee rin g
The U n iv e rs ity o f S o u th ern C a lif o r n ia
In P a r t i a l F u lfillm e n t
o f th e R equirem ents f o r th e Degree
M aster o f S cien ce in Chem ical E n g in ee rin g
by
Suham Hasan A l-M adfai
June 195S
U M I Number: EP41759
All rights reserved
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C k M l e t
This thesis, written by
Suham Hasan Al-Madfai
under the guidance of his Facuity Committee
and approved by all its members, has been
presented to and accepted by the School of
Engineering in partial fulfillment of the re
quirements for the degree of
Master of Science
Faculty Committee
U
Chairman
L ,..F hdJkcJL
A C K N O W LED G M EN T
The a u th o r w ishes to th a n k D r. H. L. F ris c h f o r
h is guidance and encouragem ent w hich alo n e have made th e
w ritin g o f t h i s t h e s i s p o s s ib le . The a u th o r would a ls o
li k e to th an k D r. K. J , M ysels f o r h is i n t e r e s t in th e
problem as w e ll a s th e v a lu a b le s u g g e s tio n s g iv en and
d is c u s s io n s c a r r ie d out in c o n n e c tio n w ith th e e x p e r
im en ta l work.
TABLE OF CONTENTS
CHAPTER PAGE
I . INTRODUCTION.................................................................. 1
I I . THEORIES OF SURFACE TENSION OF POLYM ER
SOLUTION....................................................................... 6
i n . EXPERIMENTAL WORK......................................................... 9
M a te ria l used . ................................................... 9
A pparatus ................................................................. 11
P ro ced u re . . . . . . . . . ............................ l6
Development o f A p p aratu s and P ro ced u re . 2©
1 7 . RESULTS A N D DISCUSSIONS . . . .................................23
7 . SU M M A R Y A N D CONCLUSIONS................................................ 3^
BIBLIOGRAPHY........................................................................................^1
APPENDIX .......................................................................................
l i s t of tables
TA BLE PAG E
I . S u rfa c e te n s io n in crem en ts f o r p o ly v in y l
in w ater s o lu tio n s a t 25 + 0 .1 0° . . . . 24
I I . S u rfa c e te n s io n in crem en ts f o r p o ly s ty re n e
in t e t r a l i n s o lu tio n s a t 25 + 0 . 1 Co . . 31
I I I , S u rfa c e te n s io n d a ta f o r p o ly v in y l a lc o h o l
in w ater s o lu tio n s a t 25 + 0 .1 C°
M o lecu lar w eig h t of 765,000 .. ..... 47
IV. S u rfa c e te n s io n d a ta f o r p o ly v in y l a lc o h o l
in w ater s o lu tio n s a t 25 7 0 .1 C°
M oleoular w eight o f 112,000 . . . . . . ' 46
V. S u rfa c e te n s io n d a ta f o r p o ly s ty re n e in
t e t r a l i n s o lu tio n s a t 25 4 0 .1 0°
M o lecu lar w eig h t o f 1 .5 X 10^ 49
Supplem entary to Tahle V ...................... 50
VI. S u rfa c e te n s io n d a ta f o r p o ly s ty re n e in
t e t r a l i n s o lu tio n s a t 25 I 0 ,1 0°
M olecular w eig h t o f 6 .0 X 10^ ................... 51
V II. S u rfa c e te n s io n d a ta f o r p o ly s ty re n e in
t e t r a l i n s o lu tio n s a t 25 T 0 ,1 0°
M o lecu lar w eight o f 6 .7 X 10^ . . . . . . 52
V III. S u rfac e te n s io n d a ta f o r p o ly s ty re n e in
t e t r a l i n s o lu tio n s a t 25 4 0 . 1 0 °
M o lecu lar w eig h t o f 4 .0 X 10^ . . . . . 53
V
TA BLE PAG E
IX. S u rfa c e te n s io n d a ta f o r p o ly s ty re n e in
t e t r a l i n s o lu tio n s a t 25 + 0 .1 0°
M olecular w eig h t o f 2 .5 X 10^ . . . . . . 5^
X. S u rfac e te n s io n d a ta f o r p o ly s ty re n e in
t e t r a l i n s o lu tio n s a t 25 + 0 .1 0°
M olecular w eig h t o f 1 .6 X 10^ . . . . . . 55
X I. D e n s itie s o f polym er s o lu tio n s a t 25 0° . . 56
LIST OF FIGURES
FIGURE
1 . Diagram o f o v e r a ll a p p a r a t u s ....................... . .
2 . Diagram o f th e drop form ing d e v ic e . . . .
3 . S u rfa c e te n s io n v e rs u s age o f s u rfa c e f o r
p o ly s ty re n e in t e t r a l i n a t 25 7 0 .1 G° .
ty. S u rfa c e te n s io n v e rs u s age o f s u rfa c e f o r
p o ly v in y l a lc o h o l in w ater a t 25 7 0 .1 e °
5 . S u rfa c e te n s io n v e rs u s age o f s u rfa c e f o r
p o ly s ty re n e in t e t r a l i n a t 25 ? 0 .1 C° .
6, S u rfac e te n s io n v e rs u s age o f s u rfa c e f o r
p o ly s ty re n e in t e t r a l i n a t 25 7 0 .1 C° .
PAGE
13
!* » •
25
. 2i
. 29
CHAPTER I
I
I I 1 TR0DUCTI0I
l
i i
j i
I There ie v e ry l i t t l e known e x p e rim e n ta lly as y e t, j
I j
about th e b e h a v io r o f s y n th e tic m acrom olecules a t i n t e r
fa c e s , p a r t i c u l a r l y a t th e l i q u i d s o l u t i o n - a i r in te r f a c e .
The m easurem ent o f th e s u rfa c e te n s io n s o f s o lu tio n s o f j
i h ig h polym ers as fu n c tio n of c o n c e n tra tio n and m o lecu lar 1
< |
! w eig h t a p p e ars to be a p ro m isin g m ethod o f o b ta in in g some !
, in d ic a tio n o f th e n a tu re o f t h i s b e h a v io r. The q u e s tio n
1 o f w h eth er th e polym er ten d s to p r e f e r e n t i a l l y c o n c e n tra te j
i j
a t th e in te r f a c e o r th e b u lk o f th e s o lu tio n i s answ ered 1
; |
| once th e sig n o f th e d if fe re n c e ( A ^ ) betw een th e s u rfa c e !
J te n s io n (S .T . ) o f th e polym er s o lu tio n and th e s u rfa c e I
1 i
| te n s io n o f th e p u re s o lv e n t i s known. In th e form er c a s e , J
t i
| one speaks of a s u rfa c e a c tiv e polym er in a g iv en s o lv e n t, j
. The m agnitude o f th u s s u p p lie s a q u a n t ita tiv e m easure >
i j
: o f th e s u rfa c e a c t i v i t y and g iv e s v a lu a b le in fo rm a tio n con-!
t f
!
c e rn in g th e a d s o rp tio n o f th e polym er a t th e s u rfa c e from ;
: s o lu tio n . Such in fo rm a tio n i s o f v a lu e in c e r t a in te c h - '
; i
* n ic a l a p p lic a tio n s such as in em ulsion te c h n o lo g y , and th e !
foam f r a c tio n a tio n o f p o lym ers, e t c e te r a . The study o f j
j i
! th e m o le cu lar w eig h t dependence o f le a d s to a n o v el j
i
m ethod o f e s tim a tin g m o lecu lar w eig h t o f polym er f r a c tio n s i
i
and g iv e s , under c e r t a i n c o n d itio n s , some in d ic a tio n o f th e
I 2
shape and dim ensions o f th e m acrom olecule a t th e i n t e r
fa c e .
The h ig h m o le c u la r w eig h t and th e g r e a te r m olecu
l a r inhom ogeneity o f f r a c tio n s o f s y n th e tic h ig h p o ly
m ers le a d s us to ex p e ct d i f f e r e n t s u rfa c e te n s io n be
h a v io r from th a t o f th e low m o le cu lar w eig h t s o lu te s in
s o lu tio n , such a s th e lo n g e r r e la x a tio n tim es f o r th e a t -
I
tain m en t o f th e e q u ilib riu m s u rfa c e te n s io n o f polym er j
I
! s o lu tio n s th a n th o s e observed fo r p u re low m o lecu lar i
I
i
w eig h t s o lu te s . A lso , in a p o ly m e r-so lv e n t system , th e
i sig n o f &Y can change as th e d eg ree o f p o ly m e riz a tio n o f
! th e d is s o lv e d polym er i s d e c re a se d . This phenomenon
|c e r t a i n l y cannot be observed w ith no n -p o ly m eric
is o l u te s .
j The aim o f th e p re s e n t in v e s tig a tio n was th e stu d y
i
o f b o th th e e q u ilib riu m s u rfa c e te n s io n and th e a tta in m e n t i
i
I
o f t h i s e q u ilib riu m v a lu e in two p o ly m e r-so lv e n t system s, I
! i
jp o ly v in y l a lc o h o l-w a te r and p o l y s t y r e n e - t e t r a l i n . i
i I
P re v io u s in v e s tig a tio n s o f th e s u rfa c e te n s io n o f |
is y n th e tic h ig h polym er s o lu tio n (H .P .S . ) have been v ery j
I .
!few in number and r e s t r i c t e d to aqueous s o lu tio n s of !
polym ers ex p ected to be s u rfa c e a c tiv e ( e .g . p o ly v in y l
a l c o h o l ) and te c h n o lo g ic a lly im p o rta n t a s e m u lsify in g
!a g e n ts , e t c e te r a . Couper and E ley , (5 ) in v e s tig a te d a t
room te m p e ra tu re th e s u rfa c e te n s io n s o f aqueous s o lu tio n s
o f com m ercial sam ples o f p o ly e th y le n e g ly e o l (earbow ax)
f r a c tio n s u sin g a Genco r in g b alan ce f o r th e m easurem ents.
* 1
The m oleem lar w eig h ts o f th e sam ples by chem ical end group
a n a ly s is v a rie d from 1000 to 6000, b u t w ere found to be
c o n s id e ra b ly s m a lle r by th e fre e z in g p o in t d e p re s s io n in
n itro b e n z e n e v a ry in g o n ly from 1200 to 3100. T h is p o l
ymer was s u rfa c e a c tiv e , th e s u rfa c e a c t i v i t y in c re a s in g
somewhat w ith m o le c u la r w e ig h t; and th e r e la x a tio n tim es
f o r th e a tta in m e n t o f th e E .S .T . v a rie d from ab o u t tw enty
m inutes t o an h o u r a s th e c o n c e n tra tio n o f th e s o lu tio n
was d e c re ase d from 10"? g . / l . to 2 .5 3 c 10“3 g . / i . Ap
p li c a t i o n to t h e i r d a ta , by th e s e in v e s ti g a t o r s , o f th e
I d e a liz e d G ibbs a d s o rp tio n iso th e rm e q u a tio n ( i . e . neg
le c ti n g a l l a c t i v i t y c o r r e c tio n s ) y ie ld e d a p p a re n t s u r -
i
fa c e a re a s p e r m olecule w hich were p r o p o r tio n a l to th e
i n t r i n s i c v is c o s ity o f th e H .P .S .; th u s th e y w ere a b le
to conclude t h a t th e adsorbed polym er la y ap p ro x im ately
f l a t a t th e w a te r s u r f a c e . S im ila r ly C a p ita n i and R ig h i
(M -) found t h a t th e s u rfa c e a c t i v i t y o f sam ples o f p a r
t i a l l y h y d ro ly zed p o ly v in y l- a c e ta te s o f d i f f e r e n t m olec
u la r w eig h ts and s a p o n if ic a tio n numbers in w a te r in c re a s e d
w ith m o le c u la r w e ig h t. The s u rfa c e te n s io n s o f th e aque
ous s o lu tio n s w ere d eterm in ed a t room te m p e ra tu re . The
in c re a s e o f s u rfa c e a c t i v i t y w ith th e m o le cu lar w eig h t
o f th e polym er a p p e a rs w ith b o th o f th e above polym ers
j to be c o n s id e ra b ly s m a lle r th a n ex p ected from Traube*s
I
r u l e .
In d ir e c t c o n tr a d ic tio n w ith th e p re v io u s in v e s
t i g a t o r s , K ateh alsk y and M ille r (9 ) found t h a t th e s u r -
| fa c e a c t i v i t y o f p o ly m e th a e ry lic a c id f r a c tio n s in w a te r
< !
j d e c re a se d w ith in c re a s in g m o le cu lar w eig h t a t a l l con-
: c e n tr a tio n in v e s tig a te d . The degree o f p o ly m e ris a tio n of
I
i th e p o ly a c id s tu d ie d v a r ie d from 600 to S000. The drop
jw eig h t method a t room te m p eratu re (25°C. ) was u se d to ■
o b ta in th e s u rfa c e te n s io n s . The r e la x a tio n tim es o f th e i
■ '
i
E .S .T . w ere found to be about f iv e m inutes o r l e s s . These ;
J i n v e s tig a to r s found t h a t th e s u rfa c e te n s io n d e p re s s io n ;
'fo r a g iv en polym er c o n c e n tra tio n in c re a s e s l i n e a r l y w ith
! 1
I th e r e c ip r o c a l o f th e sq u are r o o t o f th e d eg ree o f p o ly - j
j !
■ m erizatio n o f th e p o ly a c id . The s u rfa c e a c t i v i t y was i
I j
| found to v a n ish a t ab o u t tw enty p e r c e n t io n iz a tio n p r o - j
iduced by th e a d d itio n o f a l k a l i . '
t ;
The p re c e d in g work in flu e n c e d th e ch o ice o f th e !
two system s whose s u rfa c e te n s io n b e h a v io r was in v e s tig a te d j
h e re . The f i r s t , p o ly v in y l a lc o h o l (PVA) f r a c tio n s in j
t
iw a te r was chosen b ec au se o f th e ex p ected s u rfa c e a c t i v i t y
, o f th e PVA. The second system in v e s tig a te d , was p o ly - '
I f
! s ty re n e f r a c tio n s in t e t r a l i n , w hich d i f f e r s from th e p r e - !
■ v io u s system s s tu d ie d n o t o n ly in th e use o f a non-aqueous .
i
s o lv e n t b u t a ls o in th e absence o f ( ly o p h ilic ) fu n c tio n a l i
5
groups on th e h ydrocarbon s k e le to n ©f th e polym er* The
method o f m easuring th e s u rfa c e te n s io n was a m o d ific a tio n
o f th e u su a l p en d an t drop m ethod developed by A ndreas,
H au se r, and T ucker. (3)
T h is method i s a s t a t i e a b s o lu te method w hich
allo w s re p e a te d m easurem ents on a g iv e n s u rfa c e to be
c a r r ie d o u t under c o n tr o lle d therm odynamic c o n d itio n s
(te m p e ra tu re , e t c e te r a ) to a d e s ire d accu rac y o f 0 .1
dyne/cm . o v er p ro lo n g ed p e rio d s o f th e drop l i f e . The
a d a p tio n used allow ed s tu d ie s o f unchanging d ro p s f o r
p e rio d s o f tim e in ex cess o f s ix h o u rs and m ore. A f u r th e r
ad v an tag e o f such a s t a t i e method was t h a t th e a tta in m e n t
o f th e E .S .T . co u ld be t e s t e d by th e a p p lic a tio n o f Le
C h a te lie r* s p r in c ip l e th ro u g h th e sim ple p ro c e s s o f
changing th e drop volume and h o ld in g a l l o th e r c o n d itio n s
f ix e d .
CHAPTER I I
THEORIES OF SURFACE TENSION OF PO LYM ER SOLUTIONS
R e c e n tly , th e s t a t i s t i c a l m echanics o f th e s u r -
fa e e b e h a v io r o f s o lu tio n s o f m aerom olecules h as re c e iv e d
c o n s id e ra b le a t t e n t i o n . (1 0 , 1 3 , 1 5 ) In d e p e n d e n tly o f
th e s e a tte m p ts Fumio Oosawa and Sho A sakura (1 2 ) d e riv e d
an e x p re s s io n f o r th e s u rfa c e te n s io n in crem en t ( A $ ) j
th e d if fe re n c e betw een th e E .S .T . of th e s o lu tio n and th e
s o lv e n t, f o r a s u f f i c i e n t l y d i l u t e s o lu tio n o f a random ly
c o ile d c h a in polym er. I t i s assumed t h a t th e polym er
c h a in s do n o t i n t e r a c t e n e r g e tic a ll y w ith th e s u r fa c e .
As a r e s u l t ( A X ) i s d eterm in ed o n ly by th e c o n fig u re -
I
| t i o n a l e n tro p y d e c re a se produced by th e r e s t r i c t i o n o f
j th e m icro-B row nian m otion o f th e polym ers by th e s o lu tio n
s u r fa c e . As a r e s u l t o f th e c o n f ig u r a tio n a l e n tro p y
d e c re a s e , th e polym er c o n c e n tra tio n i s d e c re a se d in th e
in te r f a c e and a s a r e s u l t th e s u rfa c e te n s io n o f th e
s o lu tio n i s la r g e r th a n t h a t o f th e p u re s o lv e n t. ( A * )
i s found to b e:
= ^ s o l u t i o n - ^ s o l v e n t = ,£ (1)
where M i s th e m o le c u la r w e ig h t, and G i s th e polym er
c o n c e n tra tio n in grams p e r e.c.
Most o f th e polym er s o lu tio n s whose s u rfa c e
7
te n s io n s have been s tu d ie d a t room te m p e ra tu re s were
s u rfa c e a c tiv e and e q u a tio n ( l ) cannot be a p p lie d . The
e n e rg e tic in te r a c ti o n s betw een polym er segm ents and th e
s u rfa c e cannot be n e g le c te d and ap p ear in m ost c a se s t h a t
were s tu d ie d to p red o m in ate o v er th e e f f e c t s o f th e en
tro p y d e c re a s e , produced by th e r e s t r i c t i o n o f th e m ic ro -
Brownian m otion. F risG h and Simha (g ), u s in g M ille r* s
method on a q u a s i - l a t t i c e model o f th e s o lu tio n , and th e
I !
j s u rfa c e f o r polym er c h a in s w ith v a ry in g d eg ree s o f d e- !
| p o s it io n a t th e i n te r f a c e d e riv e d an e x p re s sio n fo r (A 'tf )
i w hich a c c o u n ts a ls o f o r e n e rg e tic in te r a c ti o n s betw een
t
i
th e s u rfa c e and th e polym er c h a in . For th e p a r t i c u l a r
case o f a G aussian c o ile d c h a in th e y found t h a t :
A K' A0 C o n stan t 0 _ g q + 0 (C2 ) (2 )
k T M 1^
jw here A0 i s th e a c tu a l a re a o f a s u rfa c e s i t e , K i s th e
I
j a d s o rp tio n iso th erm c o n s ta n t o f th e given p o ly m e r-so lv e n t
I system and k is th e B oltzm ann's c o n s ta n t.
; T his th e o ry le a d s u s to ex p ect two c a te g o r ie s o f
s u rfa c e te n s io n b e h a v io r from polym ers in t h e i r s o lu tio n s :
The f i r s t c a te g o ry a p p lie s when th e re a r e s tro n g
, e n e rg e tic a t t r a t i v e in te r a c ti o n s betw een th e s u rfa c e and
j th e polym er segm ents le a d in g to s u rfa c e a c t i v i t y . Such |
! would be th e case i f th e polym er c o n s is te d o f a ly o p h o b ic !
: backbone c h a in to w hich a re r e g u la r ly a tta c h e d ly o p h ilic
g
f u n c tio n a l g roups, th e l a t t e r le a d in g to p o s it iv e ad so rp
tio n o f th e polym er segm ents on th e s u rfa c e . In t h i s case
th e n e g a tiv e term in e q u a tio n (2 ) due to a d s o rp tio n a t th e
s u rfa c e (KC ) would predom inate o v er th e p o s it iv e term due
to c o n f ig u r a tio n a l e n tro p y , and th e polym er s o lu tio n w ould
have a s u rfa c e te n s io n low er th a n th a t o f th e p u re s o l
v e n t. The s u rfa c e te n s io n m easurem ents in t h i s case i s
a co n v e n ien t means o f fo llo w in g th e e x te n t to w hich th e I
polym er i s p o s it iv e l y ad so rb ed a t th e s o lu tio n i n t e r f a c e .
The second ty p e o f b e h a v io r would be ex p ected
when th e re i s o n ly weak e n e rg e tic in te r a c ti o n betw een th e j
i i
I polym er segm ents and th e s u r fa c e , and when th e polym ers
i
j have s u f f i c i e n t l y low m o le c u la r w e ig h t. In such a case
th e c o n f ig u r a tio n a l en tro p y term would be no lo n g e r
n e g l ig ib le , and w ould p red o m in ate over th e p o s itiv e a d -
| s o r p tio n term , th u s changing th e sig n of A ^ to p lu s . j
| Thus th e s u rfa c e te n s io n o f th e polym er s o lu tio n would be
i S ince a t c o n s ta n t te m p e ra tu re (T ) and e o n c e n tra - |
I I
• tio n ( 0 ) , th e a d s o rp tio n iso th e rm c o n s ta n t (K) i s la r g e r J
f o r a poor polym er s o lv e n t th a n f o r a good one, i t i s ^
I
j ex p ecte d th a t th e s u rfa c e a c t i v i t y o f a polym er be la r g e r
I
j in th e p o o r s o lv e n t (g).
h ig h e r th a n th e p u re s o lv e n t.
CHAPTER I I I
EXPERIMENTAL W O R K
A. MATERIAL USED
1 . P o ly v in y l a lc o h o l (PVA): The PVA u sed was
lem ol (2 2 -6 6 , l o t Sl-Rh) s u p p lie d by th e Borden Company,
C hem ical D iv is io n , Monomer D epartm ent. A ccording to th e
m a n u fa c tu re r i t had th e fo llo w in g a n a ly s is :
a c e ty l c o n te n t 12$
i
$ h y d ro ly siB 87-819$
$ v o l a t i l e 5$
Ash (as lagO ) 0. 6$
S a p o n ific a tio n range 126-147
S u rface T ension o f ab o u t 4 0 dynes/cm . (4$ s o lu
tio n )
The PVA was f r a c tio n a te d by fo llo w in g th e p ro c e
dure d eveloped by P ro fe s s o r P h ilip C. S ch e re r ( l 4 ) o f
Duke U n iv e rs ity : to 4 0.0 grams o f th e PVA sam ple in a
6 - l i t e r E rlenm eyer f la s k was added I 960 grams o f d is
t i l l e d w ate r and th e m ix tu re was h e a te d on a w a te r b a th
a t 60- 9Q°C u n t i l th e s o lu tio n was a p p a re n tly co m p lete.
The s o lu tio n was co o led to 25°C and th e t o t a l w eig h t o f
s o lu tio n b ro u g h t back to 2000 grams by a d d itio n o f w a te r.
! The s o lu tio n was th e n h e a te d u n d er a 3-T oot w a te r co n -
i
| d e n ser to 65°C and 1170 grams o f n -p ro p y l a lc o h o l and
j
500 grams o f a } ,2 : 1 by w eig h t n -p ro p y l a lc o h o l-a q u e o u s
s o lu tio n was added w ith v ig o ro u s s t i r r i n g .
j The system was co o led to 25°C and then allow ed to
s ta a d tw e n ty -fo u r h o u rs a t 15°C. At th e end o f t h i s
p e rio d th e s u p e rn a ta n t l i q u i d was d ecan ted and th e g e l
a t th e bottom was c o l le c te d as f r a c t i o n 1 . The g e l was
| d is s o lv e d in a p p ro x im a tely 250 m l. o f h o t d i s t i l l e d w a te r,
t
poured in to a f l a t bottom pyrex d is h and d r ie d a t 75 ±
j 10°C. The r e s u l t a n t f ilm was removed and u se d . The d e -
I o
| c a n te d liq u i d was h e a te d under a co n d en ser to 65-70 C and
| th e n e x t p o r tio n of n o n -s o lv e n t was added a f t e r which th e
| tre a tm e n t was th e same a s t h a t which y ie ld e d f r a c t i o n 1 .
Four f r a c t i o n s were c o lle c te d ; th e f i r s t w eighed about
0 .2 gram s, th e second 0.95 gram s, th e t h i r d 3 gram s, and
th e f o u r th ab o u t 3-5 gram s.
The d e g re e s o f p o ly m e riz a tio n o f th e PYA f r a c tio n s
w ere determ ined by u s in g th e e q u a tio n (7)?
{Hi* k p*
w here [ i s th e i n t r i n s i c v i s c o s i t y , P i s th e d eg ree
of p o ly m e riz a tio n and K and oi a re c o n s ta n ts . For PYA th e y
a re known to be (11) 7 -5 X 10"^ and 0 .6 4 r e s p e c tiv e ly a t
30°C. The d eg ree o f p o ly m e riz a tio n o f th e l a s t th r e e
f r a c t i o n s w ere d eterm in ed and found to be 2570 f o r f r a c
tio n 2 , 2100 f o r f r a c t i o n 3 > 1740 f o r f r a c t i o n 4 .
Only f r a c tio n s number 2 and 4 were l a t e r u se d .
2 . W ater: th e w a te r used was o rd in a ry d i s t i l l e d
1
w a te r h av in g an av erag e v a lu e o f s u rfa c e te n s io n o f 71.0
± 0 .3 dynes p e r cm.
3 . P o ly s ty re n e (P S T ):- Two o f th e PST f r a c tio n s
u se d were s u p p lie d by th e Dow Ohemical Company and a c -
; c o rd in g to th e m a n u fa c tu re r, th e f i r s t sample had a w eight
i av erag e m o le c u la r w eig h t o f 60,000 and was o b ta in e d from
s ty re n e p o ly m erized a t a te m p e ra tu re o f 1 #0°C, w h ile th e
second had a w eight av e ra g e m o le c u la r w eight o f 1 .5 X 10^
and was o b ta in e d from s ty re n e p o ly m e rized a t a te m p e ra tu re
o f J 0°C . The above m o le c u la r w eig h t v a lu e s w ere d e te r
m ined by l i g h t s c a t t e r i n g . The r e s t o f th e PST sam ples
w ere “liv in g " PST polym er sam ples s u p p lie d by P ro fe s s o r
M. Szw arc. A ccording to P ro fe s s o r S zw arc's la b o ra to ry
th e y had v is c o s ity av e rag e m o le c u la r w eig h ts o f 1 6 ,0 0 0 ,
2 5 ,0 0 0 , ^ 0 ,0 0 0 , and # 7 ,0 0 0 .
H -. T e tr a lin : The t e t r a l i n u sed was an Eastman
O rganic C hem icals p ro d u c t, p r a c t i c a l g ra d e ; d r ie d o v er
m e ta llic sodium th en d i s t i l l e d , and th e c o n s ta n t b o ilin g
f r a c tio n o f 207. 9°G was c o lle c te d and u se d . T h is f r a c
tio n had a s u rfa c e te n s io n v a lu e o f 35*30 dynes/cm . w hich
d id n o t change w ith tim e a s com pared to a v a lu e o f 35.26
dynes/cm . o b ta in e d from th e l i t e r a t u r e (1).
B. APPARATUS
The a p p a ra tu s u sed (F ig u re l ) was a m o d ific a tio n
o f th a t u se d by A ndreas, H auser and Tucker (3) f o r
12
i
i
j m easuring th e s u rfa c e te n s io n fey th e p en d an t drop m ethod.
i
| I t p rim a rily e o n s is ts o f a l i g h t s o u re e , an a d s o rp tio n
i c e l l , a drop form ing d e v ic e , a s h u t t e r w ith a m ieroseope
!
j o b je c tiv e and a p o la ro id cam era. The a b s o rp tio n c e l l and
; th e drop form ing d e v ice a re k e p t a t 25 *, 0 » l° c hy therm o-
s ta te d ja c k e ts . F ig u re 1 shows a g e n e ra l view o f th e
i
a p p a ra tu s u s e d . F ig u re 2 shows th e drop form ing s e c tio n
in d e t a i l .
T aking each u n it o f th e a p p a ra tu s s e p a r a te ly :
1 . A l i g h t so u rce u n it (F ig u re 1 ,G) composed o f
a f l a s h u n i t (Hardwood E eo n o flash Model 111) , and an i l
lu m in a to r (Ceneo O p tic a l Bench i ll u m in a to r ) , a rra n g e d so
th a t th e fila m e n ts o f th e illu m in a to r and th e f l a s h u n it
b u lb s were on th e same l e v e l .
2 . A th e rm o sta te d e e l l Chamber (F ig u re 1 , 1 }
composed o f an a b s o rp tio n c e l l (F ig u re 2 ,B) surrounded
by a th e rm o s ta te d m e ta llic jack et, (F ig u re 1 ,D) t h a t has
a s id e opening th ro u g h w hich th e l i g h t can p a s s . The ab
s o rp tio n e e llw a s a p y rez g la s s a b s o rp tio n e e l l , o b ta in e d
from th e American In stru m e n t Company, h av in g th e fo llo w in g
d im en sio n s; 19*5 o u ts id e w id th , 25 mm. o u ts id e h e ig h t,
25 mm. o p tic a l p a th , w ith a 10 mm. h e ig h t n eck . The c e l l
mouth was c lo s e d by a serum b o t t l e ru b b e r c a p . A sh arp
edged s t a i n l e s s s t e e l c a p i l l a r y was used to in tro d u c e th e
drop form ing fla t-g ro u n d hypoderm ic n e e d le in to th e c e l l
WATER
WATER '
.J ..
tinwmmwwmmmm
v r / 7 n' wmmmmmim
FIGURE 1
D IA G RA M OF OVERALL APPARATUS
V
I K
WATER OUT
razzEr
I U I
WATER IN
FIGURE 2
D IAG RA M OF TH E DROP FORM ING DEVICE
! 15
I
j (F ig u re 2 ,D ). T his was done "by p u sh in g th e c a p i l l a r y
j th ro u g h th e ru b b e r ca p , th en th e n e e d le was in tro d u c e d
{ th ro u g h th e c a p ill a r y in to th e c e l l . L a te r th e c a p ill a r y
j was p u lle d o u t, th u s c lo s in g th e c e l l and k eep in g th e
I n e e d le in s id e th e c e l l .
! .3 . The drop form ing d ev ice was a m ic ro b u re tte
| w ith a t e f l o n - g la s s n e e d le v alv e (F ig u re 2 ,F ) (s u p p lie d
i
by th e Em il G rin e r Company) w ith a g la s s t i p made to f i t
a s ta n d a rd hypoderm ic n e e d le j o i n t . The t i p s o f th e
hypoderm ic n e e d le s w ere c u t by a f i l e and ground v ery
' c a r e f u lly by an o i l sto n e p e rp e n d ic u la r to th e v e r t i c a l
a x i s . The drop form ing d ev ice was clam ped to a m e ta llic
h o ld e r (F ig u re 2 ,G ), w hich was screw ed v ery t i g h t l y to a
m icroscope s ta g e (F ig u re 2 , H), w hich was a b le to move
v e r t i c a l l y and sid ew ay s. The m icro sco p e s ta g e was Bcrewed
to a m e ta llic sta n d (F ig u re 2 ,K ), w hich was a tta c h e d to
th e o p tic a l bench.
4 . Around th e c e l l chamber and th e drop form ing
d ev ice a rem ovable th e rm o s ta te d ja c k e t (F ig u re 2 , J ) , was
b u i l t w ith therm om eter, p l a s t i c door and two c i r c u l a r s id e
o penings f o r th e l i g h t p a th . W ater was pumped to t h i s
|th e rm o s ta te d ja ck et, and th e c e l l chamber from a w a te r b a th
k e p t a t 25 4; 0 .1 °C . The pump v ib r a tio n s were ab so rb ed by
a ru b b er h o se . To s e c u re b e t t e r c o n tr o l o f th e te m p e ra tu re ,
an a i r c o n d itio n in g u n it was i n s t a l l e d in th e room to keep
_____________
j i t aro u n d 25°C.
5 . A m icroscope o b je c tiv e o f (X 10 ), m a g n ific a
tio n power to ta k e p ic tu r e s o f th e d ro p s, (F ig u re 1 ,K ),
was a tta c h e d to an a lp h a Ho. 4- sy n ch ro n ized s h u tte r
(F ig re 1,L ), w ith a fo c u sin g mount a tta c h e d to a Bausch
and Lomb type a d a p te r (s u p p lie d by Max Erb In stru m e n t
Company, Los A ngeles ). With a v is u a l sc re e n f o r c a r e f u l
jfo c u s in g , a Land ty p e p o la ro id cam era (F ig u re 1,M ), was j
! u se d . The a c tu a l m a g n ific a tio n power was d eterm in ed ex - J
1
p e rim e n ta lly by com paring th e a c tu a l d iam eter o f th e
n e e d le to t h a t in th e drop p i c t u r e s .
!
| All o f th e above u n its w ere mounted in th e o rd e r !
j o f l i g h t so u rc e , c e l l and drop form ing d e v ie e , and cam era
1
th e same a s in (F ig u re 1 ), on o p tic a l bench r i d e r s and
tig h te n e d to th e o p tic a l bench. The o p tic a l bench was
m ounted on v ib r a tio n a b so rb e n t ru b b e r pads (F ig u re 1,A), j
1
in o rd e r to e lim in a te a l l o u ts id e v ib r a tio n e f f e c t s . j
: 1
! 6 . A t r a v e l l i n g m icroscope w hich re a d s to 0.001 ;
i !
I cm. was u se d to m easure th e drop dim ensions from th e |
i . . . 1
I p h o to g rap h s which re a d s to 0 .0 0 1 cm. I
! I
I ,
0 . PROCEDURE j
j The drop form ing d e v ic e , i . e . th e m ic ro b u re tte
1 w ith th e te f lo n - g la s s n e e d le v a lv e , and th e hypoderm ic
I . !
1 n ee d le w ith a f la t- g r o u n d t i p w ere v ery c a r e f u l ly c le a n e d , j
17
! The te f lo n and g la s s p a r t s o f th e drop form ing d ev ice w ere
c le a n e d w ith f r e s h ly p re p a re d c le a n in g s o lu tio n , r in s e d
w ith d i s t i l l e d w ate r s e v e r a l tim e s , th e n d r ie d . The
: s t a i n l e s s s t e e l hypoderm ic n e e d le s were washed s e v e r a l
1 tim es w ith th e s o lv e n t and d r ie d b e fo re b e in g u se d . j
The polym er s o lu tio n s to be s tu d ie d w ere p re p a re d
I
by d is s o lv in g 1 gram o f th e polym er in s o lv e n t to make
1 0 0 m l. o f s o lu tio n . The l e s s c o n c e n tra te d s o lu tio n s
w ere made from th e one p e r c e n t polym er s o lu tio n by d i
l u ti o n w ith th e s o lv e n t. The polym er s o lu tio n to be
s tu d ie d was lo a d ed in to th e m ic ro b u re tte and th e n ee d le
was fo rc e d th ro u g h th e serum ru b b e r cap cover o f th e c e l l
and in s id e th e a b s o rp tio n c e l l . A fterw ard s th e c a p i l l a r y
was p u lle d o u t. The c lo s e d c e l l volume was th e n s a tu r a te d
w ith s o lv e n t v ap o rs by hanging a drop o f th e polym er s o lu
tio n in s id e th e c e l l u n t i l e v a p o ra tio n c e a se d . Then th e
drop was sucked up c o m p le te ly , th u s le a v in g th e c e l l s a t
u r a te d w ith s o lv e n t v a p o rs , A drop o f a p ro p e r s iz e (2 )
was form ed from a f r e s h polym er s o lu tio n by opening th e
t e f lo n - g l a s s n e e d le v a lv e v ery slo w ly and c a r e f u lly t i l l
th e drop was form ed on th e t i p o f th e hypoderm ic n e e d le .
Then th e v a lv e was c lo s e d v ery t i g h t l y to p re v e n t any
le a k a g e o f th e s o lu tio n th ro u g h th e v a lv e th u s keeping
th e volume o f th e drop c o n s ta n t. The drop was c a r e f u lly
fo cu sed by u s in g th e v is u a l sc re e n o f th e cam era a d a p te r
!
I
| and a s s u rin g very sh a rp drop p h o to g ra p h s. P ic tu r e s o f
j
• th e drop w ere ta k en a t d i f f e r e n t tim e i n t e r v a l s . The drop
; t
| form ing d ev ice and th e a b s o rp tio n c e l l were m a in ta in e d j
I _ i
| a t 25 + 0 .1 ° 0 . by means o f th e rm o s ta te d ja c k e ts su rro u n d -
| in g th e a b s o rp tio n c e l l and th e drop form ing d e v ic e .
W ater a t 25 + 0 . 1° 0 . was pumped th ro u g h th e s e ja c k e ts
i from a w a te r b a th k e p t a t 25 + 0 . 1°G.
! •
1 A fte r th e p ic tu r e s w ere ta k e n and d ev elo p ed , th e
i
i shape f a c t o r s (3 ) o f th e drops (S ) were d eterm in ed by
1
j j
' m easuring th e e q u a to r ia l d ia m ete r (d e ) and a s e le c te d
! p la n e d ia m eter (ds ) ta k en a t a d is ta n c e from th e end o f ■
| th e drop e q u al to th e e q u a to r ia l d iam eter (d e ) w here, I
i
i s = ? £ §
I de
l A c tu a lly de was found by draw ing two p a r a l l e l l in e s
j ta n g e n t to th e drop on th e e q u a to r. The d is ta n c e (de ) was
th e n p r o je c te d upw ard from th e end o f th e drop by a p a i r
| o f com passes and a h o r iz o n ta l l i n e drawn from th a t d i s - |
1 tan ce gave th e v a lu e (ds ). These l i n e s w ere drawn by th e j
a i d o f a sh arp p e n c il, T -sq u are and a t r i a n g l e . These
i
: i
I l in e s w ere drawn e i t h e r p e rp e n d ic u la r or p a r a l l e l to a |
J 1
i guide l i n e form ed by hanging a s t r i n g w ith a uniform lo a d I
in s id e th e camera a d a p te r . A t r a v e l l i n g m icroscope was
u sed in m easuring th e s e d ia m e te rs to + 0.001 cm. From !
1 i
th e a v a ila b le ta b le s (2 ), th e fu n c tio n ( l / H ) was o b ta in e d 1
: th a t co rre sp o n d s to th e v a lu e s o f (S ) f o r each p ic tu r e ,
19
j th en th e s u rfa c e te n s io n was c a lc u la te d from th e e q u a tio n
| ( 3 ).
0 = 1 / H I &e Z X Dg5 X g
: i
j w h ere: j
| V = S u rfac e te n s io n in dynes p e r cm. j
j l/H = a fu n c tio n o f th e shape f a c t o r (S ) j
d« = e q u a to r ia l d ia m e te r (cm .) i
n 1
D25 = D en sity o f th e s o lu tio n a t 25 0 . The ,
! d e n s ity o f th e s o lu tio n was o b ta in e d by i
i !
u s in g a pycnom eter.
g = The a c c e le r a tio n due to g r a v ity , was ta k e n
to be $80 cm /se c .^ !
! The a c tu a l v a lu e o f (de ) was d eterm in ed by d iv id in g th e
f i
I e q u a to r ia l d ia m eter m easured from th e p ic tu r e s by th e
m a g n ific a tio n pow er. j
i The m easured s u rfa c e te n s io n v a lu e s w ere p lo tt e d
| a g a in s t age o f th e s u rfa c e on r e c ta n g u la r c o o rd in a te s !
f o r each ru n . G e n e ra lly th e r e s u l t s showed th a t th e s u r - |
i
! fa c e te n s io n -tim e cu rv es le v e le d o u t and th e re was no j
j f u r t h e r change in th e s u rfa c e te n s io n v a lu e s w ith tim e . |
: 1
Where th e curve le v e le d o u t, th e h o r iz o n ta l asym ptote to !
1 I
th e cu rv e was ta k en as th e e q u ilib riu m s u rfa c e te n s io n j
! v a lu e o f th e polym er s o lu tio n . !
As a c a l i b r a t i o n t e s t f o r th e a p p a ra tu s and
p ro c e d u re u se d , th e s u rfa c e te n s io n s o f some liq u id s o f
2 0
| known s u rfa c e te n s io n were m easured* F or t e t r a l i n a s u r
fa c e te n s io n v alu e o f 3^.30 dynes/cm . was o b ta in e d com
p ared to 3^*26 dynes/cm . from th e l i t e r a t u r e (1 ) , F or
i
: w a te r a s u rfa c e te n s io n v a lu e o f (7 2 .0 - 71*0) dynes/cm .
was o b ta in e d compared to a v alu e o f 72.00 dynes/em . ob
ta in e d from th e l i t e r a t u r e (2 ).
To t e s t th e r e p r o d u c t i b i l i t y o f th e m easurem ents,
I
two s e p a ra te m easurem ents w ere made on one PVA-water
i
i s o lu tio n , and th e maximum amount o f d e v ia tio n was found
I to be ab o u t T 0 .3 dynes p e r cm, in th e e q u ilib riu m s u r -
I fa c e te n s io n . A lso two s e p a ra te m easurem ents were made
j on one sample o f PST - in t e t r a l i n , and a d e v ia tio n of
ab o u t 7 0 .1 dynes/cm . was n o tic e d in th e e q u ilib riu m s u r
fa c e te n s io n .
The above se tu p allow ed s tu d ie s o f s u rfa c e te n
s io n o f s o lu tio n s f o r more th a n tw e n ty -fo u r h o u rs; how
e v e r, in m ost c a se s a p e rio d o f l e s s th a n two h o u rs was
needed to o b ta in th e e q u ilib riu m s u rfa c e te n s io n .
DEVELOPM ENT OF APPARATUS A M D PROCEDURE
I n d ev elo p in g th e p re s e n t a p p a ra tu s and p ro c e
d u re , many problem s were fa c e d . Some o f th o se problem s
w ere:
1 . T here was a change of volume and shape o f th e
drop due to e v a p o ra tio n o f th e s o lv e n t. In th e e a r ly
s ta g e s o f th e work an o rd in a ry hypoderm ic sy rin g e was
! 21
I used as a drop form ing d e v ic e , and u sin g such a se tu p
alw ays r e s u lte d in a d e c re a se in th e drop volum e. T h is
was due to th e e v a p o ra tio n o f th e liq u i d from th e to p
1 p a r t o f th e sy rin g e , w hich r e s u lt e d in th e liq u id p u llin g
upward due t o c a p il l a r y a c tio n in th e v e ry narrow space
( betw een th e p lu n g e r and th e c y lin d e r o f th e s y rin g e . As
i
i
I a r e s u l t , th e drop was sucked upward and hence a d e c re a se
I in th e drop volume was o b se rv e d . At one tim e a p l a s t i c
I
0 - rin g was f i t t e d a t th e to p o f th e s y rin g e to sto p th e
exposure o f th e l i q u i d to th e a i r in o rd e r to p re v e n t
j e v a p o ra tio n . T hat was n o t s a t i s f a c t o r y . V ase lin e was
i a ls o used t o co v e r th e to p p a r t o f th e s y rin g e . T h is
e lim in a te d e v a p o ra tio n from th e to p p a r t o f th e sy rin g e
and c o n s ta n t volume d ro p s w ere o b ta in e d . However, th e
I
i
use o f v a s e lin e would cause c o n ta m in a tio n and hence c r e a te
more s e rio u s p ro b lem s. F in a lly a m ic ro b u re tte w ith a
te f l o n - g l a s s n e e d le v a lv e was used and t h a t gave e x c e lle n t
e o n tro l on th e drop volum e.
2 . A nother problem was th e s a tu r a tio n o f th e
c e l l volume w ith s o lv e n t v ap o rs to e lim in a te any p o s s ib le
e v a p o ra tio n from th e drops th e m se lv e s. E a rly a tte m p ts
w ere made by p la c in g some o f th e s o lv e n t in th e bottom
o f th e c e l l . Over lo n g p e r io d s , changes in th e drop s iz e s
were n o tic e d p rim a rily due to t r a n s f e r o f m ass betw een th e
so lv e n t a t th e bottom o f th e c e l l and th e d rop under stu d y ,
2 2
; due to th e c u rv a tu re o f th e s u r f a c e s . T h is problem was
f i n a l l y so lv e d by hanging a d rop o f th e s o lu tio n in s id e
th e c e l l f o r sometime to s a t u r a t e th e c e l l volume w ith
v a p o rs. L a te r t h i s drop was sucked b ack , th u s le a v in g
th e volume s a tu r a te d w ith v ap o rs w ith o u t le a v in g any
f r e e liq u id s u r fa c e .
3 . A n o th er problem was th e p o s s ib le contam ina
t i o n o f th e n e e d le when i t was pushed th ro u g h th e ru b b e r
cap in to th e c e l l . In s o lv in g t h i s problem , a sh arp
edged s t a i n l e s s s t e e l e a p i l l a r y was used to c u t th ro u g h
th e ru b b e r cap th ro u g h w hich th e n e e d le was low ered in to
th e c e l l . A fterw ard s th e c a p i l l a r y was removed le a v in g
th e n e e d le in s id e th e c e l l .
D i f f i c u l t i e s were a ls o fa c e d in r e g u la tin g
and k eep in g th e te m p e ra tu re a t 25°C. e s p e c i a lly d u rin g
th e summer. That w as so lv ed by i n s t a l l i n g an a i r con
d itio n in g u n it in th e room, k eep in g th e te m p eratu re a t
25°C.
CHAPTER IV
RESULTS A M D DISCUSSIONS
The p re s e n t s e c tio n d e a ls w ith th e a c tu a l ex
p e rim e n ta l r e s u l t s obained and t h e i r in t e r p r e t a t i o n s in
th e l i g h t o f a r e c e n tly developed th e o ry o f th e s u rfa c e
b e h a v io r o f h ig h polym er s o lu tio n s .
The s u rfa c e te n s io n v a lu e s a t d i f f e r e n t tim e in
t e r v a l s f o r each ru n w ere p lo tte d a g a in s t th e age o f th e
s u rfa c e in r e c ta n g u la r c o o rd in a te s . The r e s u l t i n g c u rv e ,
in a l l e a se s le v e le d o u t a t a p o in t where f u r th e r changes
in s u rfa c e te n s io n were no lo n g e r d e te c ta b le . The e q u i
lib r iu m s u rfa c e te n s io n (E .S .T .) was1 ta k e n to be th e
h o r iz o n ta l asym ptote to t h a t c u rv e . The r e p r o d u c ib il ity
o f t h i s method o f o b ta in in g th e 1ST f o r polym er s o lu
t i o n s was checked by making s u c c e s siv e s u rfa c e te n s io n
m easurem ents on one polym er s o lu tio n . Com paring th e r e
s u l t s o f th e s e ru n s ( fig u r e 3)» th e r e p r o d u c ib il ity o f
th e method was found to be w ith in a maximum e r r o r o f
0 .5 $ f o r a l l ru n s a tte m p te d .
i
One o f th e p o ly m e r-so lv e n t system s whose s u rfa c e
te n s io n was in v e s tig a te d was th e p o ly v in y l a lc o h o l -
w ate r system . Two o f th e fo u r p o ly v in y l a lc o h o l f r a c tio n s
p re p a re d w ere in v e s tig a te d . Aqueous s o lu tio n s o f th e s e
f r a c t i o n s o f c o n c e n tra tio n s of one gram , 0 .5 gram s, and
j
24
0 .2 grams in 100 m l. o f s o lu tio n w ere made and s tu d ie d .
The PVA f r a c tio n h a rin g a v i s c o s i t y av e ra g e d eg ree o f
p o ly m e riz a tio n (V .A .D .P.) ©f 2570 gave 1ST v a lu e s o f
4 S >.4 d y n e s/cm ., 51*5 dyne s /c m ., and 52.3 dynes/em . f o r
th e th r e e above m entioned c o n c e n tr a tio n s , r e s p e c tiv e ly .
W hile th e PVA f r a c t i o n h av in g a V .A .D .P. o f 174© gave
EST v a lu e s o f 50.5 d y n e s/c m ., 53.0 d y n e s/e m ., and
5*1-.7 dynes/cm . f o r th e above m entioned c o n c e n tra tio n
r e s p e c tiv e ly . F ig u re 4 shows a ty p i e a l p lo t o f s u rfa c e
te n s io n v a lu e s v e rsu s age o f s u rfa c e f o r th e PVA-water
system .
Taking { ) as th e EST o f th e polym er s o lu tio n
m inus th e s u rfa c e te n s io n o f th e p u re s o lv e n t, th e f o l
low ing ta b le sum m arizes th e r e s u l t s o b ta in e d on th e PYA-
w ate r sy stem .
TABU I
SURFACE TENSION INCREMENTS FOR POLYVINYL ALCO
HOL IN W ATER SOLUTIONS AT 25 7 0 .1 C°
—a— r T i i f :.......r a i'T T .fyr'ss
V is c o s ity C o n c en tra- ) dynes/cm
Degree o f t i o n gram / ) 1$
0 . 5%
0.2%
P o ly m eriza 100 ml s o lu -)
tio n (Y .A .D .P.) t i o n )
1740 - 2 0 .2
- 1J .7
- 1 6 .5
2570
- 22.5
- 11.7
- i £ .3
I N DYNES P E R CENTIMETER
36.0
1% PST— TETRALIN AT 25±0.1°C
MOL. WEIGHT = 1.5 X 10®
35.5
o RUN MADE MAY 30, I957
• RUN MADE JULY 11, 1957
35.0
34.5
3 4 .4 DY/CM
34.0
33.5
3 3 .0
30 5 0 60
AGING TIME IN MINUTES
20 40 70 80
MINUTES
90 100 110 120
FIGURE 3
I N DYNES P E R CENTIMETER
6 0
1.0% PVA - H 2 O AT 23 + 01C
O Pv = 1740
• Pv z 2 5 7 0
58
56
50
60
0 0
120 /60 0 100
20
AGING TIME IN MINUTES M
FIGURE 4
The n e g a tiv e s ig n o f a Y in d ic a te d t h a t th e EST v a lu e s
o f th e p o ly v in y l a lc o h o l s o lu tio n s were low er th a n t h a t
o f th e s o lv e n t; t h a t i s , th e FYA in w a te r was s u rfa c e
a c tiv e and th e re was p o s itiv e a b s o rp tio n o f th e polym er
j
segm ents a t th e s u r f a c e . From Table I i t was n o tic e d
t h a t th e s u rfa c e a c t i v i t y o f th e P7A in c re a s e d w ith an
in c re a s e in th e m o le c u la r w eig h t and th e s u rfa c e a c t i v i t y
d ec re a se d w ith a d e c re a se in th e c o n c e n tr a tio n , w ith a
l i n e a r r e l a t i o n betw een th e s u rfa c e te n s io n decrem ent
and th e c o n c e n tr a tio n . G e n e ra lly th e tim e ta k e n
t o e s ta b lis h th e 1ST f o r th e P7A s o lu tio n s was about one
h o u r.
S ix p o ly s ty re n e f r a c t i o n s in t e t r a l i n s o lu tio n
i
j w ere in v e s tig a te d and th e s e f r a c t i o n s had m o le c u la r
! w eig h ts o f 1 .5 X 106 , g .7 X l© *, 6.0 X 10^ , H-.O X 1©^,
I k . k
i 2 .5 X 10 , and 1 .6 X 10 . S o lu tio n s o f th e s e f r a c tio n s
o f c o n c e n tra tio n of one gram in 100 m l. o f s o lu tio n gave
EST v a lu e s of 3^.26 d y n e s/c m ., 3^»^5 d y n es/cm ., 3^.6 dynes/
cm ., 3^*9 d y n es/c m ., 35-6 d y n e s/c m ., and 35»$ dynes/cm .
f o r th e above m entioned m o le c u la r w e ig h ts r e s p e c tiv e ly .
The t e t r a l i n used had a s u rfa c e te n s io n o f 35*3^ dynes/cm .
j F ig u re 5 shows a t y p i c a l p lo t o f th e s u rfa c e te n s io n
v a lu e s v e rs u s age o f th e s u rfa c e f o r th e Dow p o ly s ty re n e
f r a c t i o n s , w h ile F ig u re 6 shows a ty p ic a l p lo t o f s u rfa c e
te n s io n v e rsu s age o f s u rfa c e f o r th e Szwarc p o ly s ty re n e
y I N DYNES PER CENTIMETER
37
1%PST— TETRALIN AT25°C±0.1
MOL. WEIGHT = 60,000
o
— — o —
c)
~ 3 4 . € > dy/ cm
(
o
)
O
o
0 10 20 30 40 50 60 70 80 90 100
AGING TIME IN MINUTES
ro
FIGURE 5 01
I N dynes per c e n t im e t e r
38
37
36
35
3 4
PST-TETRAL1N AT Z5± 0.|°C
o m o l. WElGHl = 16,000
£ MOL. WEIGHT = 25,000
C=l °/o
o t
\
c )
J * -
J i o
O (
-------- £ ----
o
•
— # —
20 40 60
AGING TIME
80 100
IN MINUTES
120 »40
FIGURE 6
ro
vo
p o ly m ers. I t i s e v id e n t t h a t th e r e i s a d if f e r e n c e in
th e approach t o th e SST f o r th e s e two ty p e s o f p o ly s ty re n e
p o ly m ers, m ain ly t h a t th e Szwarc p o ly s ty re n e f r a c t i o n a t
ta in e d th e 1ST v e ry r a p id ly , w h ile th e Dow f r a c t i o n s r e -
| q u ire d some tim e t o a t t a i n t h e i r 1ST. T hat was b e lie v e d
i
j to be due to th e g r e a te r p u r i t y and hom ogeneity o f th e
Szwarc p o ly m ers.
I t was n o tic e d t h a t s o lu tio n s o f th e p o ly s ty re n e
f r a c t i o n h av in g m o le c u la r w e i^ its o f 1 .5 X 1 0 ^ to H-.0 X
k
10 a t d i f f e r e n t c o n c e n tra tio n s showed s l i g h t s u rfa c e
a c t i v i t y in t e t r a l i n . They have 1ST v a lu e s low er th a n
t h a t o f th e t e t r a l i n by a f r a c ti o n o f a dyne , w hich in
d ic a te s t h a t some p o s itiv e a d s o rp tio n o f th e polym er
segm ents a t th e su rfa c e had ta k e n p la c e . T h is s u rfa c e
a c t i v i t y in c re a s e d w ith in c re a s in g m o le c u la r w e ig h t, and
d ec re ase d w ith a d e c re a se in c o n c e n tr a tio n . The s o lu tio n s
o f low m o le c u la r w eig h t PST f r a c t i o n s , t h a t i s , th e
1 l k
2 .5 X 10^ and 1 .6 X 10 f r a c tio n s a t d i f f e r e n t c o n c e n tra
t i o n s gave 1ST v a lu e s h ig h e r th a n th e s o lv e n t, in d ic a tin g
n e g a tiv e a d s o rp tio n o f th e polym er a t th e s u r f a c e , i . e .
th e polym er was le a v in g th e s u rfa c e to go i n t o th e bulk
o f th e s o lu tio n . T h is s u rfa c e te n s io n e le v a tio n was found
t o in c re a s e w ith d e c re a s in g m o le cu lar w e ig h ts and d e
c re a s e w ith d e c re a s in g c o n c e n tra tio n o f th e polym er in
s o lu tio n .
3 1 i
Taking a X a s th e EST o f th e polym er s o lu tio n
m inus th e s u rfa c e te n s io n o f th e s o lv e n t, th e fo llo w in g
i
ta b le sum m arizes th e o v e r a ll EST r e s u l t s o f th e p o l-
y s t y r e n e - t e t r a l i n sy stem .
TABLE I I
SURFACE TENSION INCREMENTS FOR POLYSTYRENE
IN TETRALIN SOLUTIONS AT 25 4 0 .1 C O
M o lecu lar 0 (gm/100 ml
W eight s o l u t i o n )
A
X C ly jties/cm
1 f o
0.75 i
0 . 5$ . 0 .2 $
Source
1 .5 x 106
- 1 .0 - - 0 .1
- 0 .4 Bow
S .? X 104 - 0 .5 - - 0 .1 - Szwarc
6 .0 X 104 - 0 .2
-
- O.jt
- 0 -2
Dow
4 .0 X io 4
- 0 .2
- - 0 .1 - Szwarc
2 .5 X i o 4 * 0 .1 4 0 .2 4 0 .1 - Szwarc
1 .6 X 104
* 0 .1 * 0 .2 4 0 .1 - Szwarc
The above e x p e rim e n ta l r e s u l t s w ere found to be in a g re e
ment w ith a r e c e n tly develo p ed th e o ry on th e s u rfa c e te n
s io n o f h ig h polym er s o lu tio n s by F ris c h and Simha (S ).
P o ly v in y l a lc o h o l in w a te r was found to b e , as
e x p e c te d , s u rfa c e a c t i v e . T his s u rfa c e a c t i v i t y was be
lie v e d to be due to e n e rg e tic in te r a c tio n s betw een th e
polym er segm ents and th e s u r fa c e , w hich c o u ld be a t t r i b
u te d to th e s tr u c t u r e o f th e p o ly v in y l a lc o h o l w hich
32
c o n s is ts o f a lo n g hydrophobic hydrocarbon c h a in w ith
h y d ro p h ilic f u n c tio n a l groups a tta c h e d to each segm ent.
A lso, as p r e d ic te d by th e th e o ry , th e s u rfa c e a c t i v i t y o f
th e p o ly v in y l a lc o h o l was found to in c re a s e w ith in c re a s
in g m o le c u la r w e ig h ts, and d e c re a se l i n e a r l y w ith a de
c re a s e in c o n c e n tr a tio n . PVA was found to f a l l w e ll w ith
in th e f i r s t c a te g o ry o f b e h a v io r th a t th e th e o ry would
p r e d ic t f o r a h ig h polym er in s o lu tio n . In th e PVA ca se
th e n e g a tiv e term due to p o s itiv e a d s o rp tio n in th e equa
tio n (g>):
a Y A n
s C o n stan t 0 _ g; q (2)
k T T^/Z
would p redom inate o v er th e sm a ll p o s itiv e term o f the
c o n f ig u r a tio n a l e n tro p y d e c re a se ; th u s A'tf w i l l have
a n e g a tiv e s ig n and th e polym er w i l l be s u rfa c e a c tiv e .
j In th e c a se o f th e p o l y s t y r e n e - t e t r a l i n system ,
1
S w hich i s a hydrocarbon s o lu te in a hydrocarbon s o lv e n t, th e
i
j s u rfa c e a c t i v i t y o f th e polym er was e x p e c te d to be sm a ll,
I
j s in c e t e t r a l i n i s n o t only a good so lv e n t f o r th e polym er, j
b u t a ls o due to th e absence o f any s tro n g a t t r a c t i v e in - j
te r a c t i o n o f th e polym er segm ents a t th e s u r f a c e . T his ^
i
| ,
i co u ld be a t t r i b u t e d to th e ab sen ce o f any fu n c tio n a l
groups in th e h y d ro carb o n s k e le to n o f th e polym er w hich j
!
would cause stro n g p o s it iv e a d s o rp tio n o f th e polym er se g - ;
m ents a t th e s u r fa c e . In d eed , t h i s was th e c a s e , and only
33
th e h ig h m o le c u la r w eig h t f r a c t i o n s o f th e PST showed a
s l i g h t s u rfa c e a c t i v i t y . T his s li g h t s u rfa c e a c t i v i t y was
b e lie v e d to be due to p r e f e r e n t i a l a d s o rp tio n o f th e h ig h
m o le cu lar w eig h t polym er a t th e s u rfa c e . In e q u a tio n ( 2 ) ,
fo r a h ig h v a lu e o f M, th e p o s it iv e e n tro p y te rm was v e ry
sm a ll and a s a r e s u l t th e n e g a tiv e te rm due to a d s o rp tio n
(KC) w ould be e x p e c t e d t o p r e d o m in a te . Thus th e p o ly m er
show ed s u r f a c e a c t i v i t y . T h is b e h a v io r w as shown b y t h e
fo u r h ig h m o le c u la r w eight PST f r a c tio n s s tu d ie d ra n g in g
c u
in m o le cu lar w eig h t from 1 .5 X 10 t o 4-.0 X 10 . T h e ir
1 s u rfa c e a c t i v i t y was found to in c re a s e w ith in c re a s in g
| m o le c u la r w eig h t and ro u g h ly l i n e a r l y w ith c o n c e n tra tio n ,
j F or low m o le c u la r w eig h t p o ly m ers, th e p o s itiv e e n tro p y
term was no lo n g e r n e g l ig ib le and f o r s u f f i c i e n t l y low
v a lu e s o f th e m o le c u la r w eig h t i t co u ld be la r g e enough
to p red o m in ate o v er th e n e g a tiv e term due t o a d s o rp tio n
(KG) in e q u a tio n (2 ) . Thus t h i s re v e rs e d th e s ig n o f
( A ) from m inus to p lu s . N eg ativ e a d s o rp tio n o f th e
polym er o c c u rred a t th e s u rfa c e ( i . e . d e p le tio n o f polym er
segm ents a t th e su rfa c e in fa v o r o f th e b u lk o f th e s o lu
t i o n ) . T hat was a c tu a l ly th e case in th e f r a c t i o n h av in g
m o le cu lar w eig h ts o f 2 .5 X 10^ and 1 .6 X 10^ . The s u r
fa c e te n s io n e le v a tio n was a ls o found to d e c re a se w ith
in c re a s in g m o le e u la r w eight and d e c re a s in g c o n c e n tra tio n .
; 3 *
| The s tro n g s u r fa c e a c t i v i t y o f th e p o ly v in y l a l -
! eohol in w a te r and th e s u rfa c e te n s io n b e h a v io r o f p o l
y s ty re n e in t e t r a l i n was found to be a s ex p e cte d from
;th e th e o ry (8 ) .
By ad o p tin g th e fo llo w in g n o ta tio n :
' — f \ . s / \ \ r
| G c q c *0 . 5 % (E x p e r im e n ta l)
and by u sin g th e l e a s t sq u a re curve f i t t i n g method ( r e -
! 1 l i
| M eeting th e r e s u l t s o f th e f r a c tio n M = 8 .7 X 1 0 ) , i t was
1 i
1 found t h a t th e e x p e rim e n ta l r e s u l t s o f th e p o ly s ty re n e ih
th e t e t r a l i n system co u ld be p re s e n te d by an e q u a tio n j
s im ila r to e q u a tio n (2 ) , nam ely:
- n - a 139 M "1/ 2 - 0.212 lo g 10 M
I f such a r e l a t i o n i s e s ta b lis h e d f o r any polym er-
s o lv e n t sy stem , th e n s u rfa e e te n s io n d e te rm in a tio n co u ld
be ca p ab le o f g iv in g e s tim a te s o f m o le c u la r w e ig h ts o f
f r a c tio n s o f unknown m o le c u la r w eig h ts o f t h a t polym er in
s o lu tio n , and th e s e v a lu e s would be s e n s itiv e to th e low -
m o le c u la r w eight t a i l o f th e m o le cu lar w eight d i s t r i b u t i o n .'
!
!
The tim e ta k e n to re a c h th e 1ST, i . e . th e r e la x a
t i o n tim e , was found to v ary from one p o ly m e r-so lv e n t
system to a n o th e r and f o r th e same p o ly m e r-so lv e n t system
t o be g r e a tly d ep en d en t on th e hom ogeneity o f th e polym er
j f r a c t i o n , i t s m o le c u la r w e ig h t, and c o n c e n tra tio n in
• 1
1 s o lu tio n . The more homogeneous th e polym er f r a c t i o n in
m o le c u la r w e ig h t, th e s h o r te r was th e tim e t o a t t a i n i t s
1ST. In g e n e ra l theEV A -w ater system showed la r g e r r e la x a -
i
; tio n tim e s th a n th e P S T - te tr a lin system . The Szwarc PST
| polym ers w ere m onodispersed and f r e e from r e a c tio n s id e
i
j p ro d u c ts . They needed o n ly a v e ry s h o rt tim e to a t t a i n
i
th e EST in t e t r a l i n . T heir a p p a re n t r e la x a tio n tim es were
f iv e m inutes o r l e s s , w hile t h a t o f th e Dow p o ly s ty re n e
f r a c t i o n s were tw e n ty to f o r t y m in u te s. For PVA in w ater
th e a p p a re n t r e la x a tio n tim e s were o f th e o rd e r o f an hour
o r l e s s . F ig u re 4 - i l l u s t r a t e s t h i s p o in t q u a l i t a t i v e l y
f o r two sam ples o f PVA in w a te r a t th e same c o n c e n tra tio n .
I t appeared t h a t th e f r a c t i o n h av in g V .A .D .P. o f 2 5 J 0
needed more tim e t o re a c h i t s 1ST th a n th e f r a c t i o n o f
V .A .D .P. o f 17*1-0. C o n c e n tra tio n was a n o th e r f a c t o r t h a t
e f f e c te d th e r e la x a tio n tim eq i t ap p eared t h a t th e h ig h e r
th e polym er c o n c e n tra tio n , th e s m a lle r was th e r e la x a tio n
tim e o f th e s o lu t io n . In view o f th e above o b s e rv a tio n ,
j th e p ro c e s s o f a t t a i n in g th e 1ST was b e lie v e d to be d i f -
^ fu s io n c o n tr o lle d .
i
The tim e dependence o f th e s u r fa c e te n s io n o f
th e s e polym er s o lu tio n s a p p e a rs to fo llo w th e r e l a t i o n
- Y Coo) s g - t __
^ 6 (°) - ^ (oo) ^
36
w here V i t ) i s th e s u rfa c e te n s io n a t tim e t , Y (o i
i s th e s u rfa c e te n s io n a t tim e z e ro , 0 (oo) i s th e EST
o f th e polym er s o lu t io n , and V i s th e r e la x a tio n tim e .
From th e above r e l a t i o n th e r e la x a tio n tim e ^ co u ld be
computed by p l o tt in g |h [ X ( t) - X (oo)J v e rsu s t . The
slo p e gave th e v alu e o f 1 / ^ . The one p e r c e n t PVA
s o l u t i o n s 3howed a r e l a x a t i o n t im e s o f 26.2 m in u t e s , and
36.5 m in u tes f o r th e f r a c tio n h av in g a V .A .D .P. o f 17^0
and 257G r e s p e c tiv e ly . S o lu tio n s o f one p e r ee n t PST in
t e t r a l i n showed r e la x a tio n tim e s o f a b o u t fo u rte e n m inutes
f o r th e f r a c t i o n h av in g a m o le c u la r w eight o f 6 .0 X l o \
and a b o u t 71-3 m in u tes f o r th e f r a c t i o n h av in g a m o le cu lar
6
w eig h t o f 1 .5 S 10 . V alues o f 'X were found to in c re a s e
w ith th e m o le c u la r w e ig h t. The r e l a t i o n o f 'X to th e
degree o f p o ly m e riz a tio n (D .P .) was o f th e fo llo w in g
n a t u r e :
I 1 . j p . S . l
T g i D-p - 2
f o r exam ple, f o r a one p e r e e n t s o lu tio n o f PVA in w a te r
" T m o " f f t f " 1 , 2 9 ~ — = 1 -2 6 >
w h ile a one p e r cen t s o lu tio n o f PST in t e t r a l i n
r ^ ° ° ’000 » = 5 . 0
C 60,000 J 60,000
37
j fh e above r e l a t i o n s seems to h o ld w ith in an e r r o r o f l e s s
I th a n te n p e r e e n t.
I The p ro c e s s |of a t ta i n in g th e 1ST (th e r e la x a tio n
I o f th e su rfa c e te n s io n ) was b e lie v e d to be d if f u s io n
c o n tr o lle d . I f t h i s was th e c a s e , th e n th e r e la x a tio n
tim e sh o u ld be o f th e o rd e r o f m agnitude o f th e d if f u s io n
tim e c a lc u la te d from th e E in s te in r e l a t i o n ( 6 ) = B ^ /6d ,
where 1 i s th e r a d iu s o f th e p en d an t drop and D th e d i f
fu s io n c o n s ta n t o f th e p o ly m er. For th e t v a lu e s ©b-
| ta in e d from th e p re v io u s c a lc u l a ti o n , v a lu e s o f D o b ta in e d
were o f th e o rd e r o f 10* “^ - IQ”? , w hich a r e w ith in a r e a
so n ab le range f o r v a lu e s o f D f o r d i f f e r e n t k in d s o f
polym ers (in c lu d in g p o ly s ty re n e ) in th e l i t e r a t u r e ( l 6 ).
The above r e l a t i o n g iv e s as e x p e cte d , h ig h e r v a lu e s o f D,
*
a s th e d eg ree of p o ly m e riz a tio n o f th e polym er in c r e a s e s .
*
\
CHAPTER 7
SU M M A R Y A N D CONCLUSION'S
1 . The s u rfa c e te n s io n o f polym er s o lu tio n s as
a fu n c tio n o f tim e , m o le cu lar w e ig h t, and c o n c e n tra tio n
was in v e s tig a te d . Two polym er s o lv e n t system s were
s tu d ie d , p o ly v in y l a lc o h o l in w a te r and p o ly s ty re n e in
j t e t r a l i n .
I The p en d an t drop method o f m easuring th e s u rfa c e
te n s io n was u se d . C hoice o f t h i s m ethod was based on th e
f a c t t h a t re p e a te d s t a t i c s u rfa c e te n s io n m easurem ents
co u ld be made on a s in g le su rfa c e w ith o u t d is tu r b in g th e
s u r fa c e .
2 . The r e s u l t s o f th e s e in v e s tig a tio n s w ere in
te r p r e te d in th e l i g h t o f a r e c e n tly d eveloped th e o ry on
th e s u rfa c e te n s io n o f polym er s o lu tio n s by E ris e h and
Simha ( $ ) . As ex p eeted from th e th e o ry , th e fo llo w in g
r e l a ti o n s were o b ta in e d :
a . P o ly v in y l a lc o h o l in w ater was found to be
f a i r l y s u rfa c e a c t iv e , h ig h m o le c u la r w eight
p o ly s ty re n e f r a c tio n s in t e t r a l i n w ere o n ly s l i g h t
l y s u rfa c e a c t i v e , and s o lu tio n o f low m o le cu lar
w eig h t p o ly s ty re n e f r a c tio n s showed h ig h e r s u rfa c e
te n s io n v a lu e s th a n th e s o lv e n t.
b . The a b s o lu te v a lu e o f th e s u rfa c e te n s io n
in crem en t ( A )^ ) was found to in c re a s e w ith in -
J c re a s in g m o le c u la r w e ig h t. In g e n e ra l th e
m o le cu lar w eig h t r e l a t i o n was as fo llo w s :
I
( A y )Q - = A M l / 2 - B lo g M
0
I
j where A and B a re p o s it iv e c o n s ta n ts . I t can be
I
seen th a t once such an e q u a tio n i s e s ta b lis h e d
i
I f o r a p o ly m e r-so lv e n t system , th e n s u rfa c e te n s io n j
; m easurem ents would be ca p ab le of a llo w in g e s -
i
J tim a te s o f th e m o le cu lar w eig h t o f a polym er in I
! s o lu tio n . j
i i
i i
| c . The a b s o lu te v a lu e o f th e s u rfa c e te n s io n !
increm ent ( A K ) was found to in c re a s e alm ost 1
|
l i n e a r l y w ith c o n c e n tra tio n , I
I
, 3 * tim e dependence o f th e s u rfa c e te n s io n of j
I I
|a polym er s o lu tio n and th e ap p ro ach to th e e q u ilib riu m J
i
s u rfa c e te n s io n was s tu d ie d . For system s t h a t showed
n e g a tiv e v a lu e s f o r &)£ , th e s u rfa c e te n s io n was found !
I I
■to d e c re a se w ith tim e u n t i l an e q u ilib riu m v a lu e was
re a c h e d . The r e la x a tio n tim es f o r some s u r fa c e s were
|c a lc u la te d from th e e x p e rim e n ta l d a ta and th e fo llo w in g i
( r e la tio n s w ere found to be tr u e : !
a . The r e la x a tio n tim e v a rie d from one p o ly - 1
i i -
m e r-so lv e n t to a n o th e r, and f o r th e same :
p o ly m e r-so lv e n t sy stem t to be sm a lle r th e more j
|
homogeneous th e polym er f r a c tio n in m o lecu lar I
r h - o
w e ig h t. The r e la x a tio n tim es were h ig h e s t f o r
th e p o ly v in y l a le o h o l-w a te r system and lo w est f o r
th e m onodispersed p o ly s ty re n e in t e t r a l i n s o lu
t i o n s .
b . Tbe r e la x a tio n tim es ap p e ared to be
low ered f o r more c o n c e n tra te d s o lu tio n s .
c . The r e la x a tio n tim es were found to he
g r e a te r f o r la r g e r m o le c u la r w e ig h t, and found
to be in v e rs e ly p ro p o rtio n a l to th e sq u are ro o t
o f th e d eg ree o f p o ly m e ris a tio n .
In view o f th e above f a c t s , th e ap p ro ach to th e
e q u ilib riu m s u rfa c e te n s io n was b e lie v e d to be d if f u s io n
c o n tr o lle d . The r e la x a tio n tim e i s ta k e n to be o f o rd e r
o f m agnitude o f th e d if f u s io n tim e c a lc u la te d from th e
E in s te in r e l a t i o n . The D v a lu e s c a lc u la te d
| from t h i s r e l a t i o n u s in g th e ^ v a lu e s o b ta in e d e x p e ri-
j m e n ta lly were com parable to v a lu e s o f D f o r th e polym ers
i
j i n th e l i t e r a t u r e . Thus i f v a lu e s o f a r e o b ta in e d
jfrom s u rfa c e te n s io n d a ta , a t l e a s t , approxim ate v a lu e s
}
; o f D c o u ld be c a lc u la te d from th e above r e l a t i o n .
i
BIBLIOGRAPHY
BIBLIOGRAPHY
( l ) American Chem ical S o c ie ty , P h y s ic a l P ro p e rtie s o f
Chemical Compounds. Advances in C hem istry S e r ie s .
No. 15, p . 239 {195377 j
(2 ) Am erican P etro leu m S o c ie ty , Fundam ental R esearch on
O ccurence and R ecovery o f P e tro le u m , p p . ll'4 - l^ o
(19^9 ).
(3 ) A ndreas, J . M., 1 . A. H auser and W . B. Tucker,
J . P h v s. Chem. k2, p . 1001 (1933).
(h ) C a p ita n i, C. and G. R ig h i, Compt. re n d . 27th ,
C ongress i n t e r n a t . chim . in d . B ru s s e ls 195*+> 3 , f
I n d u s tr ie chim . b e ig e 20, Spec. Nos. 691, 695
(1955)-
j ( 5 ) Couper, A. and D. A. E le y , J . Polvm er S c i . . 31,
p . 345 (19^8 ).
(6 ) E in s te in , A ., "The E lem entary Theory o f Brownian
M o tio n ," Z e it f . E lectro o h em . . !* { • (1 9 0 3 ).
(7 ) F lo ry , P., P r in c ip le s o f Polvm er C h em istry . C o rn e ll
I U n iv e rs ity P r e s s , I th a c a , N. Y. (1953 )•
(3 ) F ris c h , H. L. and R. Simha, J . Chem. P h v s. . 2 7 .
p . 702 (1 9 5 7 ).
(9 ) K atch alsk y . A. and I . M ille r , J . P h v s. Chem. 5 5 .
p . 1132 (1 9 5 1 ).
(1 0 ) M ackor, E. L. and J . H. Van d er W aals, J . C o llo id
S c i .. I , p . 535 (1 9 5 2 ).
! ( l l ) N akajim a, Akio and Eatsum i F u ru ta te , Chem. High I
j P olym ers. £ , p . 460 (19*4-9).
| (1 2 ) Oosawa, Fumio and Sho A sakura, J . Chem. P h v s.. 2 2 . j
p . 1255 (195*0. ~ j
(1 3 ) S a ro le a , L ., B u ll. Acad. Rov. B elgique (C la sse des |
S c ie n c e s ) 5° S e r ie s , hO, p . 1131 (195**- )• j
(1*0 S cherer, P . 0 ., "The Study o f R e la tio n o f th e !
I M olecular W eight D is tr ib u tio n Curves and M echanical!
P ro p e rtie s o f Some Polym er S u b sta n c e s," P ro g re ss j
■ R eport No. J. P ro je c t 256-0 1 -135. V irginia* |
P o ly te c h n ic I n s t i t u t e , B lack sb u rg , V irg in ia (1952 ).j
*3
(15) Sim ha, H ., H. L. F ris c h and F . R. E i r lc h , J* P h y s.
Ohea. 1 7 , p . 5 ^ (1 9 5 3 ); H. L. F ris c h , i f ,
i 7 T 3 3 T l 9 5 5 ) .
(16) Stuart, H '. A ., Bie Physic Ber Hochpolymeren. Bas
Makromoiekul in LSsungen. p . * 1 * 7 2 {1953)•
i
APP1HDIX
i ffiJIDE T O FIGURE 1
i A - Shock A bsorbent Rubber Pads
! B - O p tic a l Bench W ith R id e rs
i 0 - L ig h t Source
B - Removable M etal J a c k e t
E - A b so rp tio n C e ll T herm ostated Chamber
F - P yrex G lass A b so rp tio n C e ll
6 - Hypodermic Meedle
! H - T e flo n -G lass Jfeedle V alve
i
j I - Thermometer
J - Wooden Cover
| K - M icroscrope O b je c tiv e
L - S ynchronized S h u tte r
!
! M - P o la ro id Camera W ith A dapter
' QUIDS T O FIGURE 2
i A - A b so rp tio n C e ll T herm ostated Chamber
i B - P yrex G lass A b so rp tio n C e ll
0 - Serum B o ttle Rubber Gap
j D - Sharp Edged S ta in le s s S te e l C a p illa ry Tube
E - F la t Ground Tip Hypodermic H eedle
, F - T e flo n -G lass le e d le V alve
G - M ic ro b u re tte M e ta llic H older
' H - M icroscrope S tage
, I - Thermometer
J « T herm ostated M etal J a c k e t
K - M e ta llic S tand
I - M ic ro b u re tte
*7
! TABLE I I I
! SURFACE TENSION BATA FOR POLYVINYL ALCOHOL IN
W A TER SOLUTIONS AT 25 * 0 .1 C° M OLECULA R
WEIGHT OF 765,000 (D .P. = 174©)
$ Concen
t r a t i o n
gm/100 ml
s o lu t ion
0 . 5%
0.5$
0 .5 %
0.5%
o.5j
0.5 }
0.5}
0 . 2%
0 . 2$
0 . 2%
0 . 2$
0 . 2%
0 . 2%
0 . 2%
0 . 2%
0 . 2%
Age o f
d ro p s in
m in u tes
3
5
55
I
1 1
21
3©
60
69
120
2
7
20
31
63
P
167
Shape
F a c to r
S
0.6017
0.6127
0.6109
0.6140
0.6132
0.7201
0;7450
0.7417
0.7522
0 .7 4 5 !
0.7462
0.7506
0.7593
0.7610
0.7626
0.7533
0 . 766O
0.7677
0.7710
0.7651
0.7667
T
l/H
t o r i a l
B iam eter
de ( cm)
0 .
0 . 5421
O.5457
0 . 5401
0 .5416
0 .
0.6623
0.6903
0.6652
0.6601
0.6732
0.6640
0.6490
0 .6452
0 .6412
0.6401
0.6341
0.6305
0.6234
0.6361
0.6326
0.3205
0.3151
0.3124
0.3134
0.3092
0.2677
0.2924
0.2667
0.2652
0.2656
0.2626
0.2633
0.3000
0.2993
0.2966
0.2961
0.2976
0.2975
0.2974
0.2976
0.2953
Y
(dynes/em )
56.66
5 2 .6 4
52.26
52.05
50.60
60.50
57.16
55.61
53.05
5 4.47
52.76
52.26
57.24
56.64
56.04
5 5 .7 4
54.66
54.05
55.21
54.12
N eedle d ia m e te r * 0.164 cm
48
TABLE IT
SURFACE TENSION DATA FOR POLYVINYL ALCOHO L IN
W ATER SOLUTIONS AT 25 T 0 .1 G° M OLECULA R
WEIGHT OF 112,000 (D .P. = 257©)
$ Coneen-
j t r a t i o n
I gm/100 ml
' s o lu tio n
Age o f
dro p s in
m in u tes
Shape
F a c to r
l/H
Equa
t o r i a l
D iam eter
d© (cm)
Y
(dynes^bml
1$
0 .5 $
0 .5 $
0 .5 $
0 .5 $
0 . 5$
0 .5 $
0 .2$
0 .2$
0 .2$
0 .2$
0.2$
0 .2$
5
15
O
i
$
3
15
22
32
72
§
l 8
25
35
55
121
0.8036
0.6026
0.6039
0.6084
0.8079
0.6108
0.8128
O.7639
0.7758
0.7786
0.7764
0.7788
0.7764
0 . 763d
0.7749
0.7786
0.7917
0.7929
0.7917
©.5587
0.5603
0.5583
0.5499
0.5509
0.5468
0 .5424
0.6387
0.6132
0.6074
0.6112
0.6070
0.6112
0.6407
0.6151
0.6074
0.5814
0.579
0.581
o . ‘
0.3074
0.3067
0.3046
0.3022
0.3034
0.3021
0.2979
0.2947
0.2957
0.2949
0.2948
0.2932
0.3065
0.3064
0.3058
0.3061
0.3033
0.3017
52.29
5 1 * ? f
51.48
50.04
49.33
4 8 .3 6
4 8 .5 4
55.51
52.20
52.02
52 . 0“
5 1 .6
5 l.'Y
56.96
56.51
55.64
53.3.6
52.24
51. "
N eedle d ia m e te r * 0 .1 8 4 cm
49
TABLE ?
I
SURFACE TENSION D A TA FOR POLYSTYRENE I I
TETRALII SOLUTIOIS AT 25 - 0.1°C
M OLECULAR W EIGHT OF 1 .5 X 1 0 ^
$ Coneen-
t r a t i o n
gm/1 0 0 ml
s o lu tio n
Age of
drops in
m in u tes
Shape
F a c to r
S
V h
Equa
t o r i a l
D iam eter
de ( cm ) (dynes/cm ) j
* iff 3
0.5423
0 , M
0.4-934- O.2721 3 4 .6 4
l°k
22 0.4-903
0.2737
3 4 .5 0
1 $
4
P
62
0.5459
0.5469
0.4-579
0.4564
O.2733
0.2715
34.55
34.06
iff
0 . 5455 0.4-555 0.2720 3 4 .2 5
4
72 0.54-31 0.4-922 0.2725 3 4 .7 2
goo 0 .54-50
0.4-593
0.2715 3 4 .2 5
0 . 5J
5
0.54-06 0.4-961 0.2712 34.52
0 . 5J 12 0.54-22 0.4-936 0.2719
3 4.59
° .5 §
22 0.54-35 0.4-916 O.2716
3 4.35
0.5$
47
O.5397
0.4-975
0 .2715 3 4 .5 4
oM
77
0.54-04- 0.4-964- O.2716 34.70
0 .5 $
95
0.54-12
0.4952 0.2722 3 4 .7 5
0.2$ 6
14
0.54-09
0.4956 0 .2 7 1 4 3 4 .5 4
0.2 $ 0.54-20
0.4939 O .27O9 3 4 .3 0
0.2.$ 29
0.54-10
0.4955
0.2716 3 4 .6 0
0.2$ 5° 0.54-11
0.4951
0 .2 7 1 4
34.45
0.2$ 60 0.5394- 0.4950 0 .2 7 1 4
34 .7 1
N eedle d ia m eter » 0.1$*!- cm.
* Ran made May 3 0 , 1957.
SUPPLEMENTARY T O TABLE V
R e-ru n o f 1$ PST - T e tr a l in , M o lecu lar w eight
= 1 .5 X 106 a t 25 4 0 .1 0 0 . Run made J u ly
11th , 1957.
c ] o Concen
t r a t i o n
gm/lOO ml
s o lu tio n
Age o f
d ro p s in
m in u tes
Shape
F a c to r
S
1/H
Equa
t o r i a l
D iam eter
de ( cm)
Y
(dynes/cm ]
1t 5
0.3334
0.4996 O.2716
3 ^ .9
1'$
20 0.3402 0.4967 O.2717 3 4 .3
1# 35
0.3391 0.4935 O.2715 3 4 .3
1# 55
0,3419 0.4941 O.2715
3 ^ .5
11 o
71 \
0.3406 0.4961 0.2702 3 4 .4
1 %
110 0.3422 O.4936 O.2715
3 ^ .5
N eedle d ia m e te r * 0 .1 3 4 cm.
TAILS YI
SURFACE TENSION DATA FOR POLYSTYRENE IN
■ i
TETRALIN SOLUTIONS AT 25 ? 0 .1 0°
M OLECULA R WEIGHT 01 6 .0 I 10^
% Concen
t r a t i o n
gm/10© ml
s o lu tio n
Age o f
d ro p s in
m in u tes
Shape
F a c to r
S
L /H
Eq.ua-
t o r i a l
D iam eter
de ( cm)
1 %
0 .5 }
0.5%
0 .5 }
0 .5 }
0 .5 }
0 .5 $
0 .5 $
0 .5 }
0.5%
0 .2%
0.2%
0 . 2%
0.2%
0.2%
0.2%
2
1 1
3]
5 «
11
3
57
110
129
311
2I
43
0 .3
0.341
0.3433
0.3413
0.3430
0.3409
0.3397
0.3422
0.3336
0.3412
0.3339
0.3397
0.3416
0.3393
0.3337
0.3394
o.34o3
o .3 4 o 3
0.3333
0.3400
0.3403
0.4970
0.4943
0.4914
0.4950
0.4923
0.4956
0.4975
0.4936
0.4992
0.4952
0.4933
0.4975
0.4945
0.4932
0.4991
0.4930
©.4930
0.4965
0.4965
0.4997
0.4970
0.2744
0.2727
0.2730
0.2713
0.2715
0.2721
0.2723
0.2727
0.2720
0.2724
0.2724
0.2726
0.2722
O.2721
0.2725
0.2721
0.2713
0.2713
022716
0.2713
0.2716
35.73
34.97
34.74
34.69
34.43
34.30
61
35.09
34.31
35.12
34.94
34. 7©
35.05
35.01
34.73
34.75
34.70
34.93
34.30
34.70
N eedle d ia m e te r = 0 .134 em.
TABLE VII
i
i SURFACE TENSION D A TA FOR POLYSTYRENE IN
| TETRALIN SOLUTIONS AT 25 + 0 . 1 0©
I M OLECULAR WEIGHT OF 6 1 J X 104
io Concen
t r a t i o n
gm/100 ml
s o lu tio n
Age o f
drops in
m inutes
Shape
F a c to r
S
1/H
Equa
t o r i a l
D iam eter
de ( cm)
Y
( dynes/cm)
A
15
0.8396 0.4961 O.2706 34.60
55
0.8382 0.499S O .27O8 34.72
t S
92 O .836O O .5O 34 O .27O O
3^7(5
x i
120
0.8367 0.5022 O .27O O
34.70
0 .5%
12 0.8357
O .5O 35 0 . 271S 35.22
0 .5 $
? °
O .5O67 0.2719 35.49
° .5 «
Si
O.8367 0.5022 O.2716
35.13
0 .5f
60 O.8354 0.5044
0.2719
35.33
N eedle d ia m eter » 0 .1 8 4 cm
53
TABLE V III
SURFACE TENSION DATA FOR POLYSTYRENE IN
TETRALIN SOLUTIONS AT 25 ♦ 0 .1 C°
M OLECULAR WEIGHT OF 4 .0 X 1©^
$ Concen
t r a t i o n
gm/100 ml
s o lu tio n
Age of
drops in
m in u tes
Shape
F a c to r
S
Y
Equa
t o r i a l
D iam eter
de (cm)
■ .................................. ■
Y
(dynes/cm )
i i 9 0.6395 0.4977 0.2717
34.62
1*
21
O.6396
0.4961 0.2712 34.56
35 0 .6374 0.5011 0.2715
35*02
77 O.636I 0.5000 0.2714 34.91
120 O.6361 0.5000
0.2717
34.96
0.5*
6 0.6366
0.4969
0.2724
34.09
0 .5 %
20
0.6392 0.4963 0.2776 34.09
0 .54 35
0.637i4- O.5011 0.2727 35.30
0 .5 i 52
0 .6 3 9 ^
0.4960 O.2723
34.96
° - 5 |
6o
0.6363 0.4997
0.2726 35.20
0 .5% 60
o . ^ l
0.5000
0.2725
35.20
N eedle d ia m e te r = 0 .1 6 4 cm
TABLE IX
SURFACE TENSION D A TA FOR POLYSTYRENE IN
TETRALIN SOLUTIONS AT 25 4 0 .1 0°
M OLECULAR WEIGHT OF 2 .5 X 10^
f Concen
t r a t i o n
gm/tOO ml
s o lu tio n
Age o f
drops in
m in u tes
Shape
F a c to r
S
1/ h
Equa
t o r i a l
D iam eter
de (cm)
Y
(dynes/cm)
1$
10 0.2341 0 .5 0 6 4 O.2725
3 5 .6 5
i f 27
O.2351 0.5642 O.2731
35-69
50 O.S372 O .5O O O
0.2729
3 5 .3 1
i f
70 0.2437 O.5035
O.2727
3 5 .5 0
i f 113
0.2356 0.5036 O .273O
35-57
i f
122 O.2357
0.5035
O.2732 3 5 .6 0
° .7 5 § *
9
0.2353 0.5045
O.2729 3 5 .6 1
0 . 75%
0.2357
O.5032 O .273O 3 5 .6 1
°* 7 5 f
46 0.2362 O .5O21 O.2727
3 5 .3 8
0 .7 5 f l 6l 0.2364 O.5027
O.2725 3 5 .4 0
° . 5 f
15
0.2347 O .5O54 0.2721
3 5 - ^
° . 5 f
31
0.2345 O.5052 O.2716
35-3&
° . 5 f
47 O .233O O.5022 0.2716
35-51
0 .5 $ 60 0.2342 O .5O62 0.2719
3 5 -fe
0 .5 f
94
O.2345 O .5O52 O.2713
35-27
N eedle d iam eter 0 .1 2 4 cm.
55
TABLE X
SURFACE TENSION DATA FOR POLYSTYRENE IN
TITRALIN SOLUTIONS AT 25?©. 1 G °
M OLECULAR WEIGHT OF 1 .6 X 10^*
% Conoen-
t r a t ion
@m/100 ml
s o lu t ion
Age o f
d ro p s in
m inutes
"Shape
F a c to r
S
v .
H
t o r i a l
D iam eter
de (cm)
Y
(dynes/cm )
0 .7 5 $
0.75 %
0 .7 5 %
0 .7 5 %
0 .7 5 %
0.5%
0.5%
0 .5 %
7
21
36
66
12
43
17
60
63
0.6336
0.6339
0.6339
G.6344
0.6327
0.6322
0.6379
0.6353
0.6379
0.6371
0.6357
0.6403
0.6373
0.6354
0.5069
0.5067
0.5067
0.5055
0.5067
0.5095
0.5003
0 . 50^5
0.5003
0.5016
0.5036
0.4965
0.5013
0 . 50^3
0.2725
0.2724
0.2724
0.2724-
0.2724-
0.2725
0.2727
0.2737
0.2733
0.2737
0.2741
0.2726
0.2722
0.2720
•35.60
35.70
35.70
35.60
35.60
35.90
35.30
35.32
35.4-2
35.50
35.60
35.00
35.20
35.30
N eedle d ia m e te r * 0.164- cm.
TABLE XI
DENSITIES OF POLYM ER SOLUTIONS AT j
25 + 0 .1 C O IN G R A M PER ML. j
i
P o l
ymer
M o lecu lar
W eight
S o lv en t
D e n sity a t 2 5 _G° 4 0 .1 C°
in err am /ml
6 j o C o n c e n tra tio n (gm/lOOml
s o lu tio n s
if*
0 . 75$
0 .5 $
0 . < 2$
PYA 76,500 W ater 1.0005 - 1 .0 0 0 0
PVA 112,000 W ater 1.0006 -
-
PST 1 .6 X 10* T e tr a lin 0.9672
0.9669 —
PST 2 .5 X 10* T e tr a lin 0 . 967% 0.9670 -
PST %.0 X 10* T e tr a lin
0 . 967% - -
PST 6 .0 X 10* T e tr a lin
0.9679
- O .967O 6.9667
PST S. 7 X 10* T e tr a lin
0.9669
— O.9666 -
PST 1 .5 X 106 T e tr a lin 0.9676
m m
O .967O
0.9665
!
(
i
! I
| I
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Asset Metadata

Creator Al-Madfai, Suham Hasan (author)

Core Title Investigation of surface tension decrements of polymer solutions, particularly as a function of concentration and molecular weight of the dissolved polymer

Degree Master of Science

Degree Program Chemical Engineering

Publisher University of Southern California (original), University of Southern California. Libraries (digital)

Tag chemistry, polymer,engineering, chemical,OAI-PMH Harvest

Language English

Contributor Digitized by ProQuest (provenance)

Advisor Frisch, Harry L. (committee chair), Lockhart, Frank J. (committee member), Rebert, Charles J. (committee member)

Permanent Link (DOI) https://doi.org/10.25549/usctheses-c20-309011

Unique identifier UC11260258

Identifier EP41759.pdf (filename),usctheses-c20-309011 (legacy record id)

Legacy Identifier EP41759.pdf

Dmrecord 309011

Document Type Thesis

Rights Al-Madfai, Suham Hasan

Type texts

Source University of Southern California (contributing entity), University of Southern California Dissertations and Theses (collection)

Access Conditions The author retains rights to his/her dissertation, thesis or other graduate work according to U.S. copyright law. Electronic access is being provided by the USC Libraries in agreement with the au...

Repository Name University of Southern California Digital Library

Repository Location USC Digital Library, University of Southern California, University Park Campus, Los Angeles, California 90089, USA