We investigated the linear melt viscoelasticity and the crystallization kinetics of a series of model poly(ethylene oxide) stars with different functionalities (f=432 arms) and moderately entangled arms (their molecular masses ranging from 5.5to12kgmol). The limited data in the homogeneous state indicated that the zero-shear viscosity η0 was adequately described by the Milner–McLeish model for functionalities f<32, where the core effect is insignificant; a similar behavior was observed for the recoverable compliance Je0 which depended on both the molecular weight and the number of the arms. Below the melting point, the isothermal crystallization was measured with differential scanning calorimetry and rheology, and analyzed in terms of the Avrami theory, expanding over a wide range of temperatures. The results were supported by additional polarizing optical microscopy data and indicated a slower crystallization kinetics of the stars compared to their linear analogues. They showed a strong dependence of the crystallization rate on the arm molecular weight, whereas the available experimental evidence is suggestive of some functionality dependence as well.

1.
Acierno
,
S.
, and
N.
Grizzuti
, “
Measurements of the rheological behavior of a crystallizing polymer by an “inverse quenching” technique
,”
J. Rheol.
47
,
563
576
(
2003
).
2.
Alig
,
I.
,
C.
Tadjbakhsch
,
G.
Floudas
, and
C.
Tsitsilianis
, “
Viscoelastic contrast and kinetic frustration during poly(ethylene oxide) crystallization in a homopolymer and a triblock copolymer. Comparison of ultrasonic and low-frequency rheology
,”
Macromolecules
31
,
6917
6925
(
1998
).
3.
Avrami
,
M.
, “
Kinetics of phase change. I. General theory
,”
J. Chem. Phys.
7
,
1103
1112
(
1939
).
4.
Avrami
,
M.
, “
Kinetics of phase change. II. Transformation-time relations for random distribution of nuclei
,”
J. Chem. Phys.
8
,
212
224
(
1940
).
5.
Avrami
,
M.
, “
Granulation, phase change and microstructure. Kinetics of phase change. III
,”
J. Chem. Phys.
9
,
177
184
(
1941
).
6.
Bustos
,
F.
,
P.
Cassagnau
, and
R.
Fulchiron
, “
Effect of molecular architecture on quiescent and shear-induced crystallization of polyethylene
,”
J. Polym. Sci., Part B: Polym. Phys.
44
,
1597
1607
(
2006
).
7.
Chae
,
H. G.
,
B. C.
Kim
,
S. S.
Im
, and
Y. K.
Han
, “
Effect of molecular weight and branch structure on the crystallization and rheological properties of poly(butylene adipate)
,”
Polym. Eng. Sci.
41
,
1133
1139
(
2001
).
8.
Chen
,
E. Q.
,
S. W.
Lee
,
A. Q.
Zhang
,
B. S.
Moon
,
I.
Mann
,
F. W.
Harris
,
S. Z. D.
Cheng
,
B. S.
Hsiao
,
F. J.
Yeh
,
E.
von Merrewell
, and
D. T.
Grubb
, “
Isothermal thickening and thinning processes in low-molecular-weight poly(ethylene oxide) fractions crystallized from the melt. 8. Molecular shape dependence
,”
Macromolecules
32
,
4784
4793
(
1999
).
9.
Cheng
,
T. L.
, and
A. C.
Su
, “
Spherulites of long-chain branched cis-1,4-polybutadiene
,”
Macromolecules
26
,
7161
7166
(
1993
).
10.
Clarke
,
N.
,
F. R.
Colley
,
S. A.
Collins
,
L. R.
Hutchings
, and
R. L.
Thompson
, “
Self-diffusion and viscoelastic measurements of polystyrene star polymers
,”
Macromolecules
39
,
1290
1296
(
2006
).
11.
Comanita
,
B.
,
B.
Noren
, and
J.
Roovers
, “
Star poly(ethylene oxide)s from carbosilane dendrimers
,”
Macromolecules
32
,
1069
1072
(
1999
).
12.
Coppola
,
S.
,
L.
Balzano
,
E.
Gioffredi
,
P. L.
Maffettone
, and
N.
Grizzuti
, “
Effects of the degree of undercooling on flow induced crystallization in polymer melts
,”
Polymer
45
,
3249
3256
(
2004
).
13.
Doi
,
M.
, and
S. F.
Edwards
,
The Theory of Polymer Dynamics
(
Clarendon Press
,
Oxford
,
1986
).
14.
Ergoz
,
E.
,
J. G.
Fatou
, and
L.
Mandelkern
, “
Molecular-weight dependence of crystallization kinetics of linear polyethylene. 1. Experimental results
,”
Macromolecules
5
,
147
157
(
1972
).
15.
Evans
,
U. R.
, “
The laws of expanding circles and spheres in relation to the lateral growth of surface films and the grain-size of metals
,”
Trans. Faraday Soc.
41
,
365
374
(
1945
).
16.
Ferry
,
J. D.
,
Viscoelastic Properties of Polymers
(
Wiley
,
New York
,
1980
).
17.
Fetters
,
L. J.
,
A. D.
Kiss
,
D. S.
Pearson
,
G. F.
Quack
, and
F. J.
Vitus
, “
Rheological behavior of star-shaped polymers
,”
Macromolecules
26
,
647
654
(
1993
).
18.
Fetters
,
L. J.
,
D. J.
Lohse
,
D.
Richter
,
T. A.
Witten
, and
A.
Zirkel
, “
Connection between polymer molecular-weight, density, chain dimensions, and melt viscoelastic properties
,”
Macromolecules
27
,
4639
4647
(
1994
).
19.
Floudas
,
G.
,
T.
Pakula
,
E. W.
Fischer
,
N.
Hadjichristidis
, and
S.
Pispas
, “
Ordering kinetics in a symmetric diblock copolymer
,”
Acta Polym.
45
,
176
181
(
1994
).
20.
Floudas
,
G.
,
S.
Pispas
,
N.
Hadjichristidis
,
T.
Pakula
, and
I.
Erukhimovich
, “
Microphase separation in star block copolymers of styrene and isoprene. Theory, experiment and simulation
,”
Macromolecules
29
,
4142
4149
(
1996
).
21.
Floudas
,
G.
, and
C.
Tsitsilianis
, “
Crystallization kinetics of poly(ethylene oxide) in poly(ethylene oxide) polystyrene poly(ethylene oxide) triblock copolymers
,”
Macromolecules
30
,
4381
4390
(
1997
).
22.
Floudas
,
G.
,
G.
Reiter
,
O.
Lambert
, and
P.
Dumas
, “
Structure and dynamics of structure formation in model triarm star block copolymers of polystyrene, poly(ethylene oxide), and poly(epsilon-caprolactone)
,”
Macromolecules
31
,
7279
7290
(
1998
).
23.
Floudas
,
G.
,
L.
Hilliou
,
D.
Lellinger
, and
I.
Alig
, “
Shear-induced crystallization of poly(epsilon-caprolactone). 2. Evolution of birefringence and dichroism
,”
Macromolecules
33
,
6466
6472
(
2000
).
24.
Fréchet
,
J. M. J.
, and
C. J.
Hawker
, “
Synthesis and properties of dendrimers and hyperbranched polymers
,” in
Comprehensive Polymer Science
, edited by
G.
Allen
,
S. L.
Aggarwal
, and
S.
Russo
(
Pergamon
,
Oxford
,
1996
), Vol.
2
.
25.
Graessley
,
W. W.
, and
J.
Roovers
, “
Melt rheology of 4-arm and 6-arm star polystyrenes
,”
Macromolecules
12
,
959
965
(
1979
).
26.
Graessley
,
W. W.
, “
Viscoelasticity and flow in polymer melts and concentrated solutions
,” in
Physical Properties of Polymers
, edited by
J. E.
Mark
(
American Chemical Society
,
Washington, DC
,
1993
).
27.
Hadinata
,
C.
,
C.
Gabriel
,
M.
Ruellman
, and
H. M.
Laun
, “
Comparison of shear-induced crystallization behavior of PB-1 samples with different molecular weight distribution
,”
J. Rheol.
49
,
327
349
(
2005
).
28.
Haley
,
J. C.
, and
T. P.
Lodge
, “
Dynamics of a poly(ethylene oxide) tracer in a poly(methyl methacrylate) matrix: Remarkable decoupling of local and global motions
,”
J. Chem. Phys.
122
,
234
914
(
2005
).
29.
Heck
,
B.
,
T.
Hugel
,
M.
Iijima
, and
G.
Strobl
, “
Steps in the formation of the partially crystalline state
,”
Polymer
41
,
8839
8848
(
2000
).
30.
Hoffman
,
J. D.
,
J. J.
Weeks
, and
W. M.
Murphey
, “
Experimental and theoretical study of kinetics of bulk crystallization in poly(chlorotrifluoroethylene)
,”
J. Res. Natl. Bur. Stand., Sect. A
63A
,
67
98
(
1959
).
31.
Hoffman
,
J. D.
, and
J. J.
Weeks
, “
Melting process and equilibrium melting temperature of poly(chlorotrifluoroethylene)
,”
J. Res. Natl. Bur. Stand., Sect. A
66A
,
13
(
1962
).
32.
Hoffman
,
J. D.
, “
Role of reptation in the rate of crystallization of polyethylene fractions from the melt
,”
Polymer
23
,
656
670
(
1982
).
33.
Hoffman
,
J. D.
, and
R. L.
Miller
, “
Test of the reptation concept—crystal-growth rate as a function of molecular-weight in polyethylene crystallized from the melt
,”
Macromolecules
21
,
3038
3051
(
1988
).
34.
Hoffman
,
J. D.
, and
R. L.
Miller
, “
Kinetics of crystallization from the melt and chain folding in polyethylene fractions revisited: Theory and experiment
,”
Polymer
38
,
3151
3212
(
1997
).
35.
Iwata
,
K.
, “
Role of entanglement in crystalline polymers 1. Basic theory
,”
Polymer
43
,
6609
6626
(
2002
).
36.
Jayakannan
,
M.
, and
S.
Ramakrishnan
, “
Effect of branching on the crystallization kinetics of poly(ethylene terephthalate)
,”
J. Appl. Polym. Sci.
74
,
59
66
(
1999
).
37.
Kapnistos
,
M.
,
A. N.
Semenov
,
D.
Vlassopoulos
, and
J.
Roovers
, “
Viscoelastic response of hyperstar polymers in the linear regime
,”
J. Chem. Phys.
111
,
1753
1759
(
1999
).
38.
Khanna
,
Y. P.
, “
Rheological mechanism and overview of nucleated crystallization kinetics
,”
Macromolecules
26
,
3639
3643
(
1993
).
39.
Kolmogoroff
,
A. N.
, “
K statisticheskoi teorii kristallizacii metallov
,”
Izv. Akad. Nauk SSSR, Ser. Mat.
1
,
355
359
(
1937
).
40.
Kornfield
,
J. A.
,
G.
Kumaraswamy
, and
A. M.
Issaian
, “
Recent advances in understanding flow effects on polymer crystallization
,”
Ind. Eng. Chem. Res.
41
,
6383
6392
(
2002
).
41.
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
).
42.
Kumaraswamy
,
G.
, “
Crystallization of polymers from stressed melts
,”
J. Macromol. Sci., Polym. Rev.
C45
,
375
397
(
2005
).
43.
Lambert
,
W. S.
, and
P. J.
Phillips
, “
Crystallization kinetics of low-molecular-weight fractions of branched polyethylenes
,”
Macromolecules
27
,
3537
3542
(
1994
).
44.
Lambert
,
W. S.
, and
P. J.
Phillips
, “
Crystallization kinetics of fractions of branched polyethylenes.2. Effect of molecular weight
,”
Polymer
37
,
3585
3591
(
1996
).
45.
Lellinger
,
D.
,
G.
Floudas
, and
I.
Alig
, “
Shear induced crystallization in poly(epsilon-caprolactone): Effect of shear rate
,”
Polymer
44
,
5759
5769
(
2003
).
46.
Masuda
,
T.
,
Y.
Ohta
, and
S.
Onogi
, “
Rheological properties of anionic polystyrenes. III. Characterization and rheological properties of four-branch polystyrenes
,”
Macromolecules
4
,
763
768
(
1971
).
47.
McLeish
,
T. C. B.
, “
Tube theory of entangled polymer dynamics
,”
Adv. Phys.
51
,
1379
1527
(
2002
).
48.
McLeish
,
T. C. B.
, “
Why and when does dynamic tube dilation work for stars?
,”
J. Rheol.
47
,
177
198
(
2003
).
49.
McLeish
,
T. C. B.
, “
A theory for heterogeneous states of polymer melts produced by single chain crystal melting
,”
Soft Matter
3
,
83
87
(
2007
).
50.
Merrill
,
E. W.
, in
Poly(ethylene glycol) Chemistry: Biotechnical and Biomedical Applications
, edited by
J. M.
Harris
(
Plenum
,
New York
,
1992
).
51.
Milner
,
S. T.
, and
T. C. B.
McLeish
, “
Parameter-free theory for stress relaxation in star polymer melts
,”
Macromolecules
30
,
2159
2166
(
1997
).
52.
Milner
,
S. T.
, and
T. C. B.
McLeish
, “
Arm-length dependence of stress relaxation in star polymer melts
,”
Macromolecules
31
,
7479
7482
(
1998
).
53.
Nuñez
,
E. F.
,
E.
Malmstrom
,
H.
Claesson
,
P.-E.
Werner
, and
U. W.
Gedde
, “
Crystal structure, melting behavior and equilibrium melting point of star polyesters with crystallisable poly(ε-caprolactone) arms
,”
Polymer
45
,
5251
5263
(
2004
).
54.
Ohta
,
Y.
,
T.
Masuda
, and
S.
Onogi
, “
Rheological properties of anionic polystyrenes. 12. Viscosity and steady-state compliance of multibranched star polystyrenes
,”
Polym. J. (Tokyo, Jpn.)
18
,
337
346
(
1986
).
55.
Pakula
,
T.
,
S.
Geyler
,
T.
Edling
, and
D.
Boese
, “
Relaxation and viscoelastic properties of complex polymer systems
,”
Rheol. Acta
35
,
631
644
(
1996
).
56.
Pakula
,
T.
,
D.
Vlassopoulos
,
G.
Fytas
, and
J.
Roovers
, “
Structure and dynamics of melts of multiarm polymer stars
,”
Macromolecules
31
,
8931
8940
(
1998
).
57.
Pogodina
,
N. V.
, and
H. H.
Winter
, “
Polypropylene crystallization as a physical gelation process
,”
Macromolecules
31
,
8164
8172
(
1998
).
58.
Pryke
,
A.
,
R. J.
Blackwell
,
T. C. B.
McLeish
, and
R. N.
Young
, “
Synthesis, hydrogenation, and rheology of 1,2-polybutadiene star polymers
,”
Macromolecules
35
,
467
472
(
2002
).
59.
Psarski
,
M.
,
E.
Piorkowska
, and
A.
Galeski
, “
Crystallization of polyethylene from melt with lowered chain entanglements
,”
Macromolecules
33
,
916
932
(
2000
).
60.
Qiao
,
X.
,
T.
Sawada
,
Y.
Matsumiya
, and
H.
Watanabe
, “
Constraint release in moderately entangled monodisperse star polyisoprene systems
,”
Macromolecules
39
,
7333
7341
(
2006
).
61.
Raju
,
V. R.
,
H.
Rachapudy
, and
W. W.
Graessley
, “
Properties of amorphous and crystallizable hydrocarbon polymers. 4. Melt rheology of linear and star-branched hydrogenated polybutadiene
,”
J. Polym. Sci., Part B: Polym. Phys.
17
,
1223
1235
(
1979
).
62.
Rastogi
,
S.
,
D. R.
Lippits
,
G. W.
Peters
,
R.
Graf
,
Y.
Yao
, and
H. W.
Spiess
, “
Heterogeneity in polymer melts from melting of polymer crystals
,”
Nat. Mater.
4
,
635
641
(
2003
).
63.
Righetti
,
M. C.
, and
A.
Munari
, “
Influence of branching on melting behavior and isothermal crystallization of poly(butylene terephthalate)
,”
Macromol. Chem. Phys.
198
,
363
378
(
1997
).
64.
Risch
,
B. G.
,
G. L.
Wilkes
, and
J. M.
Warakomski
, “
Crystallization kinetics and morphological features of star-branched nylon-6—Effect of branch-point functionality
,”
Polymer
34
,
2330
2343
(
1993
).
65.
Roovers
,
J.
, “
Properties of the plateau zone of star-branched polybutadienes and polystyrenes
,”
Polymer
26
,
1091
1095
(
1985
).
66.
Roovers
,
J.
, “
Viscoelastic properties of 32-arm star polybutadienes
,”
Macromolecules
24
,
5895
5896
(
1991a
).
67.
Roovers
,
J.
, “
Melt rheology of highly branched polymers
,”
J. Non-Cryst. Solids
131
,
793
798
(
1991b
).
68.
Santangelo
,
P. G.
,
C. M.
Roland
, and
J. E.
Puskas
, “
Rheology of star-branched polyisobutylene
,”
Macromolecules
32
,
1972
1977
(
1999
).
69.
Seguela
,
R.
, “
Critical review of the molecular topology of semicrystalline polymers: The origin and assessment of intercrystalline tie molecules and chain entanglements
,”
J. Polym. Sci., Part B: Polym. Phys.
43
,
1729
1748
(
2005
).
70.
Slot
,
J. J. M.
, and
P. A. M.
Steeman
, “
Rheology of polydisperse star polymer melts: Extension of the parameter-free tube model of Milner and McLeish to arbitrary arm-length polydispersity
,”
Macromol. Theory Simul.
14
,
387
399
(
2005
).
71.
Stiriba
,
S.-E.
,
H.
Frey
, and
R.
Haag
, “
Dendritic polymers in biomedical applications: From potential to clinical use in diagnostics and therapy
,”
Angew. Chem., Int. Ed.
41
,
1329
1334
(
2002
).
72.
Strobl
,
G.
, “
From the melt via mesomorphic and granular crystalline layers to lamellar crystallites: A major route followed in polymer crystallization?
,”
Eur. Phys. J. E
3
,
165
183
(
2000
).
73.
Tanner
,
R. I.
, “
On the flow of crystallizing polymers I. Linear regime
,”
J. Non-Cryst. Solids
112
,
251
268
(
2003
).
74.
Toporowski
,
P. M.
, and
J.
Roovers
, “
Synthesis and properties of eighteen-arm polybutadienes
,”
J. Polym. Sci., Part A: Polym. Chem.
24
,
3009
3019
(
1986
).
75.
van Meerveld
,
J.
,
G. W. M.
Peters
, and
M.
Hutter
, “
Towards a rheological classification of flow induced crystallization experiments of polymer melts
,”
Rheol. Acta
44
,
119
134
(
2004
).
76.
Vega
,
D. A.
,
J. M.
Sebastian
,
W. B.
Russel
, and
R. A.
Register
, “
Viscoelastic properties of entangled star polymer melts: Comparison of theory and experiment
,”
Macromolecules
35
,
169
177
(
2002
).
77.
Vlassopoulos
,
D.
,
G.
Fytas
,
T.
Pakula
, and
J.
Roovers
, “
Multiarm star polymers dynamics
,”
J. Phys.: Condens. Matter
13
,
R855
R876
(
2001
).
78.
Watanabe
,
H.
, “
Viscoelasticity and dynamics of entangled polymers
,”
Prog. Polym. Sci.
24
,
1253
1403
(
1999
).
79.
Watanabe
,
H.
,
T.
Sawada
, and
Y.
Matsumiya
, “
Constraint release in star/star blends and partial tube dilation in monodisperse star systems
,”
Macromolecules
39
,
2553
2561
(
2006
).
80.
Yamada
,
K.
,
M.
Hikosaka
,
A.
Toda
,
S.
Yamazaki
, and
K.
Tagashira
, “
Equilibrium melting temperature of isotactic polypropylene with high tacticity: 1. Determination by differential scanning calorimetry
,”
Macromolecules
36
,
4790
4801
(
2003a
).
81.
Yamada
,
K.
,
M.
Hikosaka
,
A.
Toda
,
S.
Yamazaki
, and
K.
Tagashira
, “
Equilibrium melting temperature of isotactic polypropylene with high tacticity. 2. Determination by optical microscopy
,”
Macromolecules
36
,
4802
4812
(
2003b
).
82.
Yamazaki
,
S.
,
M.
Hikosaka
,
A.
Toda
,
I.
Wataoka
, and
F.
Gu
, “
Role of entanglement in nucleation and ‘melt relaxation’ of polyethylene
,”
Polymer
43
,
6585
6593
(
2002
).
83.
Yamazaki
,
S.
,
F. M.
Gu
,
K.
Watanabe
,
K.
Okada
,
A.
Toda
, and
M.
Hikosaka
, “
Two-step formation of entanglement from disentangled polymer melt detected by using nucleation rate
,”
Polymer
47
,
6422
6428
(
2006
).
84.
Zhao
,
S.
,
X.
Zhang
, and
G.
Jin
, “
Influence of molecular structure of star S-SBR on its properties
,”
J. Appl. Polym. Sci.
89
,
2311
2315
(
2003
).
You do not currently have access to this content.