Dynamics of polyisoprene in star block copolymers confined in microstructures: A dielectric spectroscopy study

G. Floudas; S. Paraskeva; N. Hadjichristidis; G. Fytas; B. Chu; A. N. Semenov

doi:10.1063/1.474255

Dynamics of polyisoprene in star block copolymers confined in microstructures: A dielectric spectroscopy study

G. Floudas^*, S. Paraskeva, N. Hadjichristidis, G. Fytas, B. Chu, A. N. Semenov

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

45 Scopus citations

Abstract

Dielectric spectroscopy has been employed to study selectively the local and global dynamics of polyisoprene (PI) in three microphase separated star diblock copolymers (SI)₄, where PI and polystyrene (PS) form the core and corona, respectively. The thermally induced order-to-disorder transition (ODT) has been identified by rheology and small-angle x-ray scattering (SAXS). All dielectric measurements were made at temperatures well below the ODT and the polystyrene glass transition temperatures, where the four PI chain ends are tethered by the glassy polystyrene domains. The ordered state morphology, studied by SAXS, revealed the formation of PS spheres (f_PS=0.25, where f_PS is the polystyrene volume fraction), polyisoprene cylinders (f_PS=0.68), and a lamellar structure (f_PS=0.41) in the three copolymers. In contrast to the local segmental motions, the chain orientational dynamics associated with the amplitude and the characteristic relaxation time are strongly influenced by the spatial confinement. The main effects are the suppressed amplitude and the enhanced chain mobility, which are predicted and found to be stronger if the star topology is accompanied by topological (entanglement) effects of the PI block, irrespective of the ordered star morphology.

Original language	English (US)
Pages (from-to)	5502-5509
Number of pages	8
Journal	JOURNAL OF CHEMICAL PHYSICS
Volume	107
Issue number	14
DOIs	https://doi.org/10.1063/1.474255
State	Published - Oct 8 1997
Externally published	Yes

ASJC Scopus subject areas

General Physics and Astronomy
Physical and Theoretical Chemistry

Access to Document

10.1063/1.474255

Cite this

@article{59b43a96ed98447a945ab0bc1c054559,

title = "Dynamics of polyisoprene in star block copolymers confined in microstructures: A dielectric spectroscopy study",

abstract = "Dielectric spectroscopy has been employed to study selectively the local and global dynamics of polyisoprene (PI) in three microphase separated star diblock copolymers (SI)4, where PI and polystyrene (PS) form the core and corona, respectively. The thermally induced order-to-disorder transition (ODT) has been identified by rheology and small-angle x-ray scattering (SAXS). All dielectric measurements were made at temperatures well below the ODT and the polystyrene glass transition temperatures, where the four PI chain ends are tethered by the glassy polystyrene domains. The ordered state morphology, studied by SAXS, revealed the formation of PS spheres (fPS=0.25, where fPS is the polystyrene volume fraction), polyisoprene cylinders (fPS=0.68), and a lamellar structure (fPS=0.41) in the three copolymers. In contrast to the local segmental motions, the chain orientational dynamics associated with the amplitude and the characteristic relaxation time are strongly influenced by the spatial confinement. The main effects are the suppressed amplitude and the enhanced chain mobility, which are predicted and found to be stronger if the star topology is accompanied by topological (entanglement) effects of the PI block, irrespective of the ordered star morphology.",

author = "G. Floudas and S. Paraskeva and N. Hadjichristidis and G. Fytas and B. Chu and Semenov, {A. N.}",

year = "1997",

month = oct,

day = "8",

doi = "10.1063/1.474255",

language = "English (US)",

volume = "107",

pages = "5502--5509",

journal = "JOURNAL OF CHEMICAL PHYSICS",

issn = "0021-9606",

publisher = "American Institute of Physics",

number = "14",

}

TY - JOUR

T1 - Dynamics of polyisoprene in star block copolymers confined in microstructures

T2 - A dielectric spectroscopy study

AU - Floudas, G.

AU - Paraskeva, S.

AU - Hadjichristidis, N.

AU - Fytas, G.

AU - Chu, B.

AU - Semenov, A. N.

PY - 1997/10/8

Y1 - 1997/10/8

N2 - Dielectric spectroscopy has been employed to study selectively the local and global dynamics of polyisoprene (PI) in three microphase separated star diblock copolymers (SI)4, where PI and polystyrene (PS) form the core and corona, respectively. The thermally induced order-to-disorder transition (ODT) has been identified by rheology and small-angle x-ray scattering (SAXS). All dielectric measurements were made at temperatures well below the ODT and the polystyrene glass transition temperatures, where the four PI chain ends are tethered by the glassy polystyrene domains. The ordered state morphology, studied by SAXS, revealed the formation of PS spheres (fPS=0.25, where fPS is the polystyrene volume fraction), polyisoprene cylinders (fPS=0.68), and a lamellar structure (fPS=0.41) in the three copolymers. In contrast to the local segmental motions, the chain orientational dynamics associated with the amplitude and the characteristic relaxation time are strongly influenced by the spatial confinement. The main effects are the suppressed amplitude and the enhanced chain mobility, which are predicted and found to be stronger if the star topology is accompanied by topological (entanglement) effects of the PI block, irrespective of the ordered star morphology.

AB - Dielectric spectroscopy has been employed to study selectively the local and global dynamics of polyisoprene (PI) in three microphase separated star diblock copolymers (SI)4, where PI and polystyrene (PS) form the core and corona, respectively. The thermally induced order-to-disorder transition (ODT) has been identified by rheology and small-angle x-ray scattering (SAXS). All dielectric measurements were made at temperatures well below the ODT and the polystyrene glass transition temperatures, where the four PI chain ends are tethered by the glassy polystyrene domains. The ordered state morphology, studied by SAXS, revealed the formation of PS spheres (fPS=0.25, where fPS is the polystyrene volume fraction), polyisoprene cylinders (fPS=0.68), and a lamellar structure (fPS=0.41) in the three copolymers. In contrast to the local segmental motions, the chain orientational dynamics associated with the amplitude and the characteristic relaxation time are strongly influenced by the spatial confinement. The main effects are the suppressed amplitude and the enhanced chain mobility, which are predicted and found to be stronger if the star topology is accompanied by topological (entanglement) effects of the PI block, irrespective of the ordered star morphology.

UR - http://www.scopus.com/inward/record.url?scp=0000098018&partnerID=8YFLogxK

U2 - 10.1063/1.474255

DO - 10.1063/1.474255

M3 - Article

AN - SCOPUS:0000098018

SN - 0021-9606

VL - 107

SP - 5502

EP - 5509

JO - JOURNAL OF CHEMICAL PHYSICS

JF - JOURNAL OF CHEMICAL PHYSICS

IS - 14

ER -

Dynamics of polyisoprene in star block copolymers confined in microstructures: A dielectric spectroscopy study

Abstract

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this