www.sciencemag.org/cgi/content/full/316/5827/1014/DC1
Supporting Online Material for
Molecular Basis of the Shish-Kebab
Morphology in Polymer Crystallization
Shuichi Kimata, Takashi Sakurai, Yosh
inobu Nozue,* Tatsuya Kasahara, Noboru
Yamaguchi, Takeshi Karino, Mitsuhiro Shibayama, Julia A. Kornfield*
*To whom correspondence should be addressed.
E-mail: nozue@sc.sumitomo-chem.co.jp (Y.N.); jak@caltech.edu (J.A.K.)
Published 18 May,
Science
316
, 1014 (2007)
DOI: 10.1126/science.1140132
This PDF file includes:
Materials and Methods
SOM Text
Figs. S1 to S7
Tables S1 and S2
References
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S
UPPOR
TING
M
ATER
IAL
Materials
Hydrogenated and deuterated isotactic
polypropylene (H-iPP
and D-iPP) w
ere
polym
erized with propene (C
3
H
6
) and deuterated propene (C
3
D
6
) respectively by an
isospecific m
etallocene cataly
st s
ystem
; di
me
thylsilyl bis(2-m
ethyl-4-naphthylindenyl)
zirconium
dichloride an
d m
ethyl alum
inoxane in toluene.
In order to control the m
olecular
weight of hydrogenated and deuterated iPP
, polym
erization tem
perature was controlled.
Using selected reaction tem
peratures betw
een 15°C to 70°C, six dif
ferent m
olecular
weights of H-iPP
and three dif
ferent m
olecu
lar weights of D-iPP
wer
e prepared. Using
high-tem
perature GPC with
o
-dichlorobenzene as an eluent and calibration based on
polystyrene standards, molecular w
eight (M
w
) and polydispersity (M
w
/M
n
) was m
easured
for each of these H-iPPs and D-iPPs (T
able S1).
Table S1. Molecular weight (M
w
) and polydispersity (M
w
/M
n
) of H-iPPs and D-iPPs
Sample N
ame
Isoto
pe
Label
ing
Mw
Mw/
Mn
H-s
49,20
0
2.3
H-m1
185,8
00
3.3
H-m2
234,4
00
3.4
H-m3
242,5
00
3.2
H-l1
996,3
00
2.6
H-l2
1,419,
900
2.8
D-s
40,90
0
2.4
D-m
196,7
00
3.2
D-l
1,780,
900
3.1
D
H
To understand the behavior of
broad di
stribution iPPs that have enorm
ous
technological relevance and have been widely
studied, we designed blends of the above
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com
ponents to produce polydispersity of Mw/M
n
≈
8.
Based on the m
easured m
olar m
ass
distributions, we com
puted th
e am
ount of each
species such
that
each b
lend would each
have Mw 490,000 g/mol and 13.3% of deuterium
-labelled chains (T
able S2).
To ensure
uniform
mol
ecular dispersion of the com
ponents,
the three model iPP
re
sins with deuterium
labeling (S
hort-D, Medium
-D and Long-D)
were prepared by solution blending: the
specified m
asses of the H-iPP
and D-iPP
specie
s were disso
lved in
boiling xylene (350 m
L)
in the presence of antioxidant
(1000ppm of IRGANOX1010 and 2000pp
m of
IRGAFOS168, distributed by C
iba Specialty Ch
em
icals) and then precipitated into
methanol with vigorous stirring.
The resulti
ng blends were dried at 60°C in vacuum
.
Table S2. Blend com
positions of the deuterium
-labeled m
odel iPP
resins
Model iPP
H-s
H-m1
H-m2
H-m3
H-l1
H-l2
D-s
D-m
D-l
Short-D
-
1.5
1.5
1.5
1.0
1.0
1.0
-
-
Medium-D
1.0
0.5
1.5
1.5
1.0
1.0
-
1.0
-
Long-D
1.0
1.5
1.5
1.5
0.5
0.5
-
-
1.0
H-i
PP (g)
D-iPP (g)
A variety o
f m
easurements were used to
confirm that the thre
e model resin
s were
adequately well m
atched: high-temperatur
e GPC measurem
ent of their m
olar m
ass
distribution and rheo-optical ch
aracterization of their behavior
during flow and subs
equent
crystallization. The rheo-opt
ical m
easure
ments provided
the basis for selecting the
conditions for inducing highly
oriented crystallization.
Shear
-indu
ced crystalliz
ation of
deuterium labeled iPP
resins
Pressure driven flow through a rectangular
slit w
as used to impose a well-defined flow
and therm
al history
. A custom apparatus
sub
jects the sa
mple to a specif
ied, high wall
shear stresses for a controlled duration, c
ontinuously m
onitoring the birefringence and
turbid
ity of
the sam
ple during and
af
ter shear
(
S1
). Rheo-optical studies guided the
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selec
tion
of
shearin
g tem
perature
(T
s
=180°C) and crystallization
tem
perature (T
c
=140°C), and
estab
lished
that a
s
hear s
tres
s of
0.14MPa was high enough to induce
the transition to highly oriented
crysta
lliza
tion (
S2
). The flow-cell
was initially
held at 21
5°C and f
illed
with polym
er m
elt from
the reservoir.
The polym
er in the flo
w-cell was then
held at 215°C for 10 m
in to erase any
memory effects caused
by the filling
process.
The sam
ple was cooled
to
T
s
=180°C and allowed to reach
a
uniform
t
emperature. Control
sam
ples (unsheared) and oriented
sam
ples (sheared a
s follows) were
prepared for each of the three b
lends.
For the oriented sam
ples, once the
tem
perature equilib
rated at 180°C, a
pressure drop across the length of the
channel was applied to drive shear
flow through the channel at a w
all
shear stress of 0.14M
Pa for a brief
shearing tim
e (1.0sec). Imm
ediately
after im
posing short-term shearing (or
none for the control), the flow-cell was
cooled to 140°C (cooling at
approxim
ately 4°C/m
in) and then held
0.0
0.2
0.4
0.6
0.8
1.0
1.2
I
to
t
/
I
to
t,0
(
a
.
u
.)
120
140
160
180
200
f
l
ow
-
c
el
l
t
epm
.
(
°
C
)
(A)
10
-1
11
0
10
2
10
3
10
4
Time ( s )
0.0
0.2
0.4
0.6
0.8
1.0
1.2
I
to
t
/
I
to
t,0
(
a
.
u
.)
120
140
160
180
200
fl
ow
-
c
el
l
tepm. (
°
C
)
(B)
10
-1
11
0
10
2
10
3
10
4
Time ( s )
0.0
0.2
0.4
0.6
0.8
1.0
1.2
I
to
t
/
I
to
t,0
(
a
.
u
.)
120
140
160
180
200
fl
ow
-
c
el
l
tepm. (
°
C
)
(C)
10
-1
11
0
10
2
10
3
10
4
Time ( s )
Figure S1. T
urbidity and
flow-cell temperature
of (A) Short-D, (B) Medium
-D and (C)
Long-D during and after short-term shearing.
The tem
perature du
rin
g cooling from
the
shearing tem
perature (180°C) to the
crystallization tem
perature (140°C) is shown
for referenc
e.
3
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at 140°C f
or 20m
in. The turbidity
and birefringence were tracked to
monitor the progress
and anisotropy of
crysta
lliza
tion of
model iPP resins.
After 20 m
inutes, to complete
solidif
icatio
n of
the sam
ple, the
flow-cell was rem
oved from the
apparatus and plunged
in cold water.
The optic
al tra
in used
f
or the
measurem
ents was
the sam
e as
described previously (
S3
). The
intensity of He-Ne laser light passing
through crossed and parallel polarizers
(
I
⊥
and
I
||
) was measured with
photodiode detectors. When
depolar
iza
tion is n
eglig
ible, the
birefringence (
∆
n
), which is a m
easure
of the m
ean aniso
tropy
of the sam
ple,
is given by
10
-1
11
0
10
2
10
3
10
4
Time ( s )
0.0
0.2
0.4
0.6
0.8
1.0
1.2
120
140
160
180
200
fl
ow
-
c
el
l
tepm. (
°
C
)
(A)
10
-1
11
0
10
2
10
3
10
4
Time ( s )
0.0
0.2
0.4
0.6
0.8
1.0
1.2
120
140
160
180
200
f
l
ow
-
c
el
l
t
epm
.
(
°
C
)
(B)
0.0
0.2
I
⊥
/
I
tot
(
a
.
u
.)
I
⊥
/
I
tot
(
a
.
u
.)
0.4
0.6
0.8
1.0
1.2
120
140
160
180
200
fl
ow
-
c
el
l
tepm. (
°
C
)
10
-1
11
0
10
2
10
3
10
4
Time ( s )
(C)
I
⊥
/
I
tot
(
a
.
u
.)
)
(
sin
||
1
I
I
I
d
n
+
−
⊥
⊥
=
∆
π
λ
where
λ
is the wavelength of light
(632.8nm
) a
nd
d
is the thickness of
the
sam
ple. T
ransm
ittance is def
ined as
tota
l transm
itted inten
sity (
I
tot
=
I
⊥
+
I
||
)
norm
alized by a constant value of
I
tot,0
before shearing.
Figure S2.
R
elativ
e intensity
th
rou
gh cross
ed
polarizers (
I
⊥
/
I
tot
) and flow-cell tem
peratu
re of
(A) Short-D, (B) Medium
-D and (C) Long-D
during and after short-term
shearing, recorded
sim
ultaneously w
ith th
e tran
sm
itte
d intens
ity
in Figure S1.
4
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For the quie
scently crystallized sam
ples, the tran
sm
ittance traces are ve
ry sim
ilar for
the three m
aterials (not shown). During sh
ear
-induced crystalliz
ation the transient
transm
ittanc
e (Figu
re S
1) and
re
tar
dance (Figu
re S2)
ar
e v
ery s
imilar f
or a
ll thre
e resins
.
As for the transm
itta
nce tra
ce, f
orm
ation
of scatter
ers becom
es evident w
hen the
tem
perature reache
s approxim
ately 150°C (m
anifested by the
drop in tra
nsm
ittance),
there
is a
brief lo
cal m
inim
um approxi
mately
100s later
, and th
e transm
itte
d inten
sity falls
to
approxim
ately 20% at 1,000s. In situ m
easurem
ents end at 1,200s when the flow cell is
rem
oved from the apparatus and plunged into cold water
.
Upon inception of shear the retard
ance passes through the usual overshoot
characteristic of highly entangled m
elts
of high polydispersity (Figure S2). The
subsequent increas
e in b
irefring
ence between
t
=0.5s and the conclusion
of shearing at 1s is
characteristic of highl
y orien
ted c
rystalliz
ation
and it is alm
ost identica
l for all three
sam
ples.
Upon cessation of shear the retard
ance drops rapidly
, evident in the drop to
I
⊥
/
I
tot
= 0.1 for all sam
ples; thus, the blends were
very well m
atched in term
s of the extent of
orien
ted cry
stalliz
ation
during
flow
. Subsequently
, while
held at 180
°C, the retardance
slowly decreased in the sa
me way for all sa
mples.
During cooling from 180°C to 140°C,
the retard
ance began to rise ag
ain, indicative of growth of
orien
ted cry
stallites, at
t
≈
200s
when T
≈
150°C. The
retardance
(2
π
d
∆
n/
λ
)
passed over orders with successive m
axim
a in
I
⊥
/
I
tot
co
rres
ponding to
increas
ing, o
dd m
ultiples
of 1/2 and success
ive m
inima correspond
to even
m
ultip
les of 1/2.
The ex
cellent m
atch of the tim
es to reac
h each o
rder (e.g.,
retardance reaches
2 waves at
t=800
s for all three sam
ples) is
a v
ery stro
ng indicatio
n that
the density of shish created during flow and
the growth of kebabs on them
are virtually
identical in all sam
ples.
At 1,800s the tr
ansm
ittance was 5%, each optical experim
ent was
term
inated and the sam
ple was rapidly c
ooled to am
bient temperature, as above.
Ex-situ exam
ination of the m
orphology of
the sam
ples using optical m
icroscopy
with polarized light (F
igure S3), transm
ission electron m
icroscopy (Figure S4), wide-angle
x-ray scattering (Figure S5 and
S6) and sm
all-angle x
-ray
scat
tering (Figure S7) confirm
ed
that their structure on length scales from
100
μ
m down to <1nm was well m
atched.
The
orien
ted skin is very un
iform
in thickness (d
ark
layers near the surface when viewed wit
h
5
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polarizer along the flow direc
tion and analyzer ort
hogonal to it, Figure
S3) and uniform
in
nanostructure (Figure S4).
The spherullitic st
ructure in the core of the s
ample has a very
fine length scale, indicative of crystalliza
tion at tem
peratures below 100°C: negligible
crysta
lliza
tion in th
is z
one occur
red duri
ng the 20 m
inutes prior to
rapid cooling from
140°C to ambient tem
perature.
.
100
μ
m
100
μ
m
flo
w
(A) (B)
(C)
100
μ
m
Figure S3. P
olarized optical m
icrograph of cross
section of solidified
specim
en ((A
) Short-D
,
(B) Medium
-D and (C) Long-D).
Relative to the flow direction,
the polarizer and analyzer
are oriented parallel a
nd orthogonal, respectively
.
100 n
m
100 n
m
flo
w
(A) (B)
(C)
100 n
m
Figure S4. T
ransm
ittan
ce elec
tron m
icrograph of
skin layer of
solidif
ied specim
en ((A
)
Short-D, (B) Medium
-D and (C) Long-D).
6
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al.
.
(
A
)
(
B
)
(
C
)
flow
Figure S5. T
wo-dim
ensional W
AXS pattern of
solidif
ied
specim
en of
(A
) Short-D
, (B
)
Medium
-D and (C) Long-D.
Small angle neutr
on scattering
(SANS) measur
ements
SANS
measurem
ents
were
perform
ed on the SANS-
U
instrum
ent owned by the Institute
for Solid-S
tate Phys
ics of
the
University of T
okyo, at the
research reactor JRR-3 located at
the Japan Atom
ic Ener
gy
Research I
nstitu
te, T
okai Japan
(
S4
). A
flux of cold neutrons with
wavelength
λ
= 7
.0Å was
inciden
t on
the sam
ple, and the
scattered
in
tensity prof
iles w
ere
collected
with an
area d
etector of
128 pixels × 128 pixels. The sa
mple-to-detector
distances were set to 2m
and 8m,
which
covered an access
ible
q
range of 0.006
−
0.1 Å
-1
. Here,
q
is the scattering vector def
ined as
4
π
sin
θ
/
λ
and 2
θ
is th
e scatter
ing angle. Sca
ttered
inten
sities were corrected fo
r cell
5
101
5
202
5
2
θ
(d
egree)
In
te
n
s
i
t
y
(
a
.
u
.
)
(A)
(B)
(C)
Figure S6. Circularly averaged W
AXS pattern of
solidified specim
en of (A)
Short-D
, (B
) Med
ium-D
and (C) Long-D
7
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scattering, transm
ission, and incoherent sca
ttering, and then scaled
to the
ab
solute
intensities with a polyethylen
e standard sam
ple (Lupolen) (
S4
,
S5
). All sam
ples were
placed under vacuum
to avoid degradation when
heated from 25°C to 180°C at 2°C/min.
(B)
eferences
raswam
y, R.
K.
Verma, J
. A. Kor
nfield,
Rev
. Sci. Inst.,
70,
2097 (1999)
,
1762
umaraswam
y, A. M. I
ssai
an, J.
A. Kor
nfield,
Macr
omolecules
32,
7537 (1999)
. Jpn.
74,
2728 (2005)
flow
(A)
(B)
(C)
F
igure S7. Two-dim
ensional SAXS pattern of
solidified specim
ens of
(A
) Short-D
,
Medium
-D and (C) Long-D.
R
S1. G
. Ku
ma
S2. G
. K
umaraswamy, J. A
. K
ornfield, F. Y
eh, B
. S
. H
siao,
Macr
omolecules
35
(2002)
S3. G
. K
S4. S. Okabe, et al.,
J. Appl.
Crystallography
,
38,
1035, (2005)
S5. M. Shibayam
a, M. Nagao, S. Okabe,
T. Karino,
J. Phys. Soc
8