With a combination of extensional rheology and in-situ small-angle X-ray scattering measurements, the protocol of two-step extension is proposed to investigate the early stage of flow-induced crystallization (FIC) in supercooled isotactic polypropylene melt at 138 °C. After both step strains, the crystallization half-time presents a nonmonotonic dependence on the interval time between two extensional operations, based on which three different stages of structural evolution are defined. In stage I, both nucleation and chain relaxation occur, which enhances the crystallization rate but reduces the final lamellar crystal orientation. In this stage, each part of the melt is considered to have approximately the same dynamics to respond homogeneously to the second extension and thus the system is still dominated by a chain-network. When entering into stage II, the sparse large-scaled crystal is formed to construct a heterogeneous crystal-network superimposed on the chain-network, which decelerates the second extension induced crystallization by causing stress concentration on the crystal-network at low faction. In stage III, the crystal-network dominates the sample deformation due to the formation of abundant lamellar crystal, which recreates the approximately same dynamics for each part of sample and brings about an enhancement of crystallization rate again. The transition from chain- to crystal-network revealed in this work demonstrates a dynamical coupling of chain relaxation, crystal nucleation, and growth in FIC of polymers.

1.
Peters
,
G. W. M.
,
L.
Balzano
, and
R. J. A.
Steenbakkers
, “
Flow‐induced crystallization
,” in
Handbook of Polymer Crystallization
(
John Wiley & Sons
,
Hoboken, NJ
,
2013
).
2.
Peterlin
,
A.
, “
Drawing and extrusion of semi-crystalline polymers
,”
Colloid. Polym. Sci.
265
,
357
382
(
1987
).
3.
Keller
,
A.
, and
J.
Kolnaar
, “
Chain extension and orientation: Fundamentals and relevance to processing and products
,”
Prog. Colloid Polym. Sci.
92
,
81
102
(
1993
).
4.
Wang
,
Z.
,
Z.
Ma
, and
L.
Li
, “
Flow-induced crystallization of polymers: Molecular and thermodynamic considerations
,”
Macromolecules
49
,
1505
1517
(
2016
).
5.
van Meerveld
,
J.
,
M.
Hütter
, and
G. W.
Peters
, “
Continuum model for the simulation of fiber spinning, with quiescent and flow-induced crystallization
,”
J. Non-Newtonian Fluid Mech.
150
,
177
195
(
2008
).
6.
Schultz
,
J.
,
B. S.
Hsiao
, and
J.
Samon
, “
Structural development during the early stages of polymer melt spinning by in-situ synchrotron X-ray techniques
,”
Polymer
41
,
8887
8895
(
2000
).
7.
Janeschitz-Kriegl
,
H.
, “
How to understand nucleation in crystallizing polymer melts under real processing conditions
,”
Colloid. Polym. Sci.
281
,
1157
1171
(
2003
).
8.
Chen
,
Y.
,
D.
Fang
,
B. S.
Hsiao
, and
Z.
Li
, “
Insight into unique deformation behavior of oriented isotactic polypropylene with branched shish-kebabs
,”
Polymer
60
,
274
283
(
2015
).
9.
Chen
,
W.
,
X.-Y.
Li
,
Y.-P.
Liu
,
J.
Li
,
W.-M.
Zhou
,
L.
Chen
, and
L.-B.
Li
, “
The spatial correlation between crystalline and amorphous orientations of isotactic polypropylene during plastic deformation: An in situ observation with FTIR imaging
,”
Chin. J. Polym. Sci.
33
,
613
620
(
2015
).
10.
Graham
,
R. S.
, and
P. D.
Olmsted
, “
Coarse-grained simulations of flow-induced nucleation in semicrystalline polymers
,”
Phys. Rev. Lett.
103
,
115702
(
2009
).
11.
Janeschitz-Kriegl
,
H.
,
E.
Ratajski
, and
M.
Stadlbauer
, “
Flow as an effective promotor of nucleation in polymer melts: A quantitative evaluation
,”
Rheol. Acta
42
,
355
364
(
2003
).
12.
Kumaraswamy
,
G.
,
A. M.
Issaian
, and
J. A.
Kornfield
, “
Shear-enhanced crystallization in isotactic polypropylene. 1. Correspondence between in situ rheo-optics and ex situ structure determination
,”
Macromolecules
32
,
7537
7547
(
1999
).
13.
Graham
,
R. S.
, and
P. D.
Olmsted
, “
Kinetic Monte Carlo simulations of flow-induced nucleation in polymer melts
,”
Faraday Discuss.
144
,
71
92
(
2010
).
14.
Kurelec
,
L.
,
S.
Rastogi
,
R.
Meier
, and
P.
Lemstra
, “
Chain mobility in polymer systems: On the borderline between solid and melt. 3. Phase transformations in nascent ultrahigh molecular weight polyethylene reactor powder at elevated pressure as revealed by in situ Raman spectroscopy
,”
Macromolecules
33
,
5593
5601
(
2000
).
15.
Somani
,
R. H.
,
B. S.
Hsiao
,
A.
Nogales
,
H.
Fruitwala
,
S.
Srinivas
, and
A. H.
Tsou
, “
Structure development during shear flow induced crystallization of i-PP: In situ wide-angle X-ray diffraction study
,”
Macromolecules
34
,
5902
5909
(
2001
).
16.
Sun
,
X.
,
H.
Li
,
J.
Wang
, and
S.
Yan
, “
Shear-induced interfacial structure of isotactic polypropylene (iPP) in iPP/fiber composites
,”
Macromolecules
39
,
8720
8726
(
2006
).
17.
García Gutiérrez
,
M.-C.
,
G. C.
Alfonso
,
C.
Riekel
, and
F.
Azzurri
, “
Spatially resolved flow-induced crystallization precursors in isotactic polystyrene by simultaneous small-and wide-angle X-ray microdiffraction
,”
Macromolecules
37
,
478
485
(
2004
).
18.
Balzano
,
L.
,
N.
Kukalyekar
,
S.
Rastogi
,
G. W.
Peters
, and
J. C.
Chadwick
, “
Crystallization and dissolution of flow-induced precursors
,”
Phys. Rev. Lett.
100
,
048302
(
2008
).
19.
Ma
,
Z.
,
L.
Balzano
, and
G. W.
Peters
, “
Pressure quench of flow-induced crystallization precursors
,”
Macromolecules
45
,
4216
4224
(
2012
).
20.
Nazari
,
B.
,
A. M.
Rhoades
,
R. P.
Schaake
, and
R. H.
Colby
, “
Flow-induced crystallization of peek: Isothermal crystallization kinetics and lifetime of flow-induced precursors during isothermal annealing
,”
ACS Macro Lett.
5
,
849
853
(
2016
).
21.
Hamad
,
F. G.
,
R. H.
Colby
, and
S. T.
Milner
, “
Lifetime of flow-induced precursors in isotactic polypropylene
,”
Macromolecules
48
,
7286
7299
(
2015
).
22.
Pennings
,
A. J.
, and
A. M.
Kiel
, “
Fractionation of polymers by crystallization from solution, III. On the morphology of fibrillar polyethylene crystals grown in solution
,”
Colloid Polym. Sci.
205
,
160
162
(
1965
).
23.
Kimata
,
S.
,
T.
Sakurai
,
Y.
Nozue
,
T.
Kasahara
,
N.
Yamaguchi
,
T.
Karino
,
M.
Shibayama
, and
J. A.
Kornfield
, “
Molecular basis of the shish-kebab morphology in polymer crystallization
,”
Science
316
,
1014
1017
(
2007
).
24.
Hsiao
,
B. S.
,
L.
Yang
,
R. H.
Somani
,
C. A.
Avila-Orta
, and
L.
Zhu
, “
Unexpected shish-kebab structure in a sheared polyethylene melt
,”
Phys. Rev. Lett.
94
,
117802
(
2005
).
25.
Ma
,
Z.
,
L.
Balzano
, and
G. W.
Peters
, “
Dissolution and re-emergence of flow-induced shish in polyethylene with a broad molecular weight distribution
,”
Macromolecules
49
,
2724
2730
(
2016
).
26.
Yang
,
H.-R.
,
J.
Lei
,
L.
Li
,
Q.
Fu
, and
Z.-M.
Li
, “
Formation of interlinked shish-kebabs in injection-molded polyethylene under the coexistence of lightly cross-linked chain network and oscillation shear flow
,”
Macromolecules
45
,
6600
6610
(
2012
).
27.
Hu
,
W.
,
D.
Frenkel
, and
V. B.
Mathot
, “
Simulation of shish-kebab crystallite induced by a single prealigned macromolecule
,”
Macromolecules
35
,
7172
7174
(
2002
).
28.
Hamad
,
F. G.
,
R. H.
Colby
, and
S. T.
Milner
, “
Transition in crystal morphology for flow-induced crystallization of isotactic polypropylene
,”
Macromolecules
49
,
5561
5575
(
2016
).
29.
Flory
,
P. J.
, “
Thermodynamics of crystallization in high polymers. I. Crystallization induced by stretching
,”
J. Chem. Phys.
15
,
397
408
(
1947
).
30.
Yeh
,
G.
, and
K.
Hong
, “
Strain
induced crystallization, Part III: Theory
,”
Polym. Eng. Sci.
19
,
395
400
(
1979
).
31.
Coppola
,
S.
,
N.
Grizzuti
, and
P. L.
Maffettone
, “
Microrheological modeling of flow-induced crystallization
,”
Macromolecules
34
,
5030
5036
(
2001
).
32.
Tian
,
N.
,
W.
Zhou
,
K.
Cui
,
Y.
Liu
,
Y.
Fang
,
X.
Wang
,
L.
Liu
, and
L.
Li
, “
Extension flow induced crystallization of poly (ethylene oxide)
,”
Macromolecules
44
,
7704
7712
(
2011
).
33.
Zhu
,
S.
,
Z.
Wang
,
F.
Su
,
W.
Zhou
,
N.
Tian
,
X.
Li
, and
L.
Li
, “
The influence of inertia and elastic retraction on flow-induced crystallization of isotactic polypropylene
,”
J. Rheol.
57
,
1281
1296
(
2013
).
34.
Wang
,
S.-Q.
,
S.
Ravindranath
,
Y.
Wang
, and
P.
Boukany
, “
New theoretical considerations in polymer rheology: Elastic breakdown of chain entanglement network
,”
J. Chem. Phys.
127
,
064903
(
2007
).
35.
Zhou
,
W.
,
K.
Cui
,
N.
Tian
,
D.
Liu
,
Y.
Liu
,
L.
Meng
,
X.
Li
,
J.
He
,
L.
Li
, and
X.
Li
, “
Disentanglement decelerating flow-induced nucleation
,”
Polymer
54
,
942
947
(
2013
).
36.
Okura
,
M.
,
O. O.
Mykhaylyk
, and
A. J.
Ryan
, “
Effect of matrix polymer on flow-induced nucleation in polymer blends
,”
Phys. Rev. Lett.
110
,
087801
(
2013
).
37.
Keum
,
J. K.
,
F.
Zuo
, and
B. S.
Hsiao
, “
Formation and stability of shear-induced shish-kebab structure in highly entangled melts of UHMWPE/HDPE blends
,”
Macromolecules
41
,
4766
4776
(
2008
).
38.
Kanaya
,
T.
,
G.
Matsuba
,
Y.
Ogino
,
K.
Nishida
,
H. M.
Shimizu
,
T.
Shinohara
,
T.
Oku
,
J.
Suzuki
, and
T.
Otomo
, “
Hierarchic structure of shish-kebab by neutron scattering in a wide Q range
,”
Macromolecules
40
,
3650
3654
(
2007
).
39.
Elmoumni
,
A.
,
R. A.
Gonzalez-Ruiz
,
E. B.
Coughlin
, and
H. H.
Winter
, “
Isotactic poly (propylene) crystallization: Role of small fractions of high or low molecular weight polymer
,”
Macromol. Chem. Phys.
206
,
125
134
(
2005
).
40.
Zhong
,
G.-J.
,
L.
Li
,
E.
Mendes
,
D.
Byelov
,
Q.
Fu
, and
Z.-M.
Li
, “
Suppression of skin-core structure in injection-molded polymer parts by in situ incorporation of a microfibrillar network
,”
Macromolecules
39
,
6771
6775
(
2006
).
41.
Xu
,
J.-Z.
,
C.
Chen
,
Y.
Wang
,
H.
Tang
,
Z.-M.
Li
, and
B. S.
Hsiao
, “
Graphene nanosheets and shear flow induced crystallization in isotactic polypropylene nanocomposites
,”
Macromolecules
44
,
2808
2818
(
2011
).
42.
Haggenmueller
,
R.
,
J. E.
Fischer
, and
K. I.
Winey
, “
Single wall carbon nanotube/polyethylene nanocomposites: Nucleating and templating polyethylene crystallites
,”
Macromolecules
39
,
2964
2971
(
2006
).
43.
Byelov
,
D.
,
P.
Panine
,
K.
Remerie
,
E.
Biemond
,
G. C.
Alfonso
, and
W. H.
de Jeu
, “
Crystallization under shear in isotactic polypropylene containing nucleators
,”
Polymer
49
,
3076
3083
(
2008
).
44.
Hwang
,
W. R.
,
G. W.
Peters
,
M. A.
Hulsen
, and
H. E.
Meijer
, “
Modeling of flow-induced crystallization of particle-filled polymers
,”
Macromolecules
39
,
8389
8398
(
2006
).
45.
Phillips
,
A. W.
,
A.
Bhatia
,
P.-W.
Zhu
, and
G.
Edward
, “
Shish formation and relaxation in sheared isotactic polypropylene containing nucleating particles
,”
Macromolecules
44
,
3517
3528
(
2011
).
46.
Balzano
,
L.
,
S.
Rastogi
, and
G. W.
Peters
, “
Crystallization and precursors during fast short-term shear
,”
Macromolecules
42
,
2088
2092
(
2009
).
47.
Heeley
,
E. L.
,
C. M.
Fernyhough
,
R. S.
Graham
,
P. D.
Olmsted
,
N. J.
Inkson
,
J.
Embery
,
D. J.
Groves
,
T. C.
McLeish
,
A. C.
Morgovan
, and
F.
Meneau
, “
Shear-induced crystallization in blends of model linear and long-chain branched hydrogenated polybutadienes
,”
Macromolecules
39
,
5058
5071
(
2006
).
48.
Ma
,
Z.
,
L.
Balzano
,
T.
van Erp
,
G.
Portale
, and
G. W.
Peters
, “
Short-term flow induced crystallization in isotactic polypropylene: How short is short?
,”
Macromolecules
46
,
9249
9258
(
2013
).
49.
Seki
,
M.
,
D. W.
Thurman
,
J. P.
Oberhauser
, and
J. A.
Kornfield
, “
Shear-mediated crystallization of isotactic polypropylene: The role of long chain-long chain overlap
,”
Macromolecules
35
,
2583
2594
(
2002
).
50.
Cui
,
K.
,
L.
Meng
,
N.
Tian
,
W.
Zhou
,
Y.
Liu
,
Z.
Wang
,
J.
He
, and
L.
Li
, “
Self-acceleration of nucleation and formation of shish in extension-induced crystallization with strain beyond fracture
,”
Macromolecules
45
,
5477
5486
(
2012
).
51.
Shen
,
B.
,
Y.
Liang
,
J. A.
Kornfield
, and
C. C.
Han
, “
Mechanism for shish formation under shear flow: An interpretation from an in situ morphological study
,”
Macromolecules
46
,
1528
1542
(
2013
).
52.
Mykhaylyk
,
O. O.
,
C. M.
Fernyhough
,
M.
Okura
,
J. P. A.
Fairclough
,
A. J.
Ryan
, and
R.
Graham
, “
Monodisperse macromolecules—A stepping stone to understanding industrial polymers
,”
Eur. Polym. J.
47
,
447
464
(
2011
).
53.
Wang
,
Y.
,
X.
Li
,
X.
Zhu
, and
S.-Q.
Wang
, “
Characterizing state of chain entanglement in entangled polymer solutions during and after large shear deformation
,”
Macromolecules
45
,
2514
2521
(
2012
).
54.
Thien
,
N. P.
, and
R. I.
Tanner
, “
A new constitutive equation derived from network theory
,”
J. Non-Newtonian Fluid Mech.
2
,
353
365
(
1977
).
55.
Housmans
,
J.-W.
,
R. J. A.
Steenbakkers
,
P. C.
Roozemond
,
G. W. M.
Peters
, and
H. E. H.
Meijer
, “
Saturation of pointlike nuclei and the transition to oriented structures in flow-induced crystallization of isotactic polypropylene
,”
Macromolecules
42
,
5728
5740
(
2009
).
56.
Liu
,
Y.
,
W.
Zhou
,
K.
Cui
,
N.
Tian
,
X.
Wang
,
L.
Liu
,
L.
Li
, and
Y.
Zhou
, “
Extensional rheometer for in situ x-ray scattering study on flow-induced crystallization of polymer
,”
Rev. Sci. Instrum.
82
,
045104
(
2011
).
57.
Mezghani
,
K.
, and
P. J.
Phillips
, “
The γ-phase of high molecular weight isotactic polypropylene: III. The equilibrium melting point and the phase diagram
,”
Polymer
39
,
3735
3744
(
1998
).
58.
Bach
,
A.
,
K.
Almdal
,
H. K.
Rasmussen
, and
O.
Hassager
, “
Elongational viscosity of narrow molar mass distribution polystyrene
,”
Macromolecules
36
,
5174
5179
(
2003
).
59.
Nielsen
,
J. K.
,
H. K.
Rasmussen
,
O.
Hassager
, and
G. H.
McKinley
, “
Elongational viscosity of monodisperse and bidisperse polystyrene melts
,”
J. Rheol.
50
,
453
476
(
2006
).
60.
van Meerveld
,
J.
,
G. W.
Peters
, and
M.
Hütter
, “
Towards a rheological classification of flow induced crystallization experiments of polymer melts
,”
Rheol. Acta
44
,
119
134
(
2004
).
61.
Yaoita
,
T.
,
T.
Isaki
,
Y.
Masubuchi
,
H.
Watanabe
,
G.
Ianniruberto
, and
G.
Marrucci
, “
Primitive chain network simulation of elongational flows of entangled linear chains: Role of finite chain extensibility
,”
Macromolecules
44
,
9675
9682
(
2011
).
62.
McKinley
,
G. H.
, and
O.
Hassager
, “
The Considere condition and rapid stretching of linear and branched polymer melts
,”
J. Rheol.
43
,
1195
1212
(
1999
).
63.
Doi
,
M.
, and
S. F.
Edwards
,
The Theory of Polymer Dynamics
(
Oxford University
,
Oxford
,
1988
).
64.
Coccorullo
,
I.
,
R.
Pantani
, and
G.
Titomanlio
, “
Spherulitic nucleation and growth rates in an iPP under continuous shear flow
,”
Macromolecules
41
,
9214
9223
(
2008
).
65.
Zuidema
,
H.
,
G. W. M.
Peters
, and
H. E. H.
Meijer
, “
Development and validation of a recoverable strain-based model for flow-induced crystallization of polymers
,”
Macromol. Theory Simul.
10
,
447
460
(
2001
).
66.
Toki
,
S.
,
I.
Sics
,
S.
Ran
,
L.
Liu
,
B. S.
Hsiao
,
S.
Murakami
,
K.
Senoo
, and
S.
Kohjiya
, “
New insights into structural development in natural rubber during uniaxial deformation by in situ synchrotron X-ray diffraction
,”
Macromolecules
35
,
6578
6584
(
2002
).
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