Europhys. Lett.
Volume 62, Number 5, June 2003
Page(s) 746 - 752
Section Interdisciplinary physics and related areas of science and technology
Published online 01 May 2003
DOI: 10.1209/epl/i2003-00436-6
Europhys. Lett., 62 (5) , pp. 746-752 (2003)

Heterogeneity of the chain segment dynamics and ordering in lamellar layers of a symmetric triblock copolymer

C. Lorthioir1, B. Deloche1, P. Auroy2 and Y. Gallot3

1  Laboratoire de Physique des Solides (CNRS-UMR 8502), Université Paris-Sud 91405 Orsay, France
2  Institut Curie (CNRS-UMR 168) - rue Pierre et Marie Curie, 75005 Paris, France
3  Institut Charles Sadron (CNRS-UPR 22) - rue Boussingault, 67083 Strasbourg, France

(Received 6 December 2002; accepted in final form 31 March 2003)

The segmental ordering within the sublayers of a lamellar polystyrene-poly dimethylsiloxane-polystyrene triblock (PS-PDMS-PS) is examined by NMR. The carbon and deuterium NMR line shapes of the PDMS sequence (soft block) reveal clearly a wide distribution of segmental orientational order S in the lamellae and thus a distribution of constraints probed by the chains. It is observed that this distribution is mainly due to the coexistence of positive and negative S, resulting from a competitive ordering effect induced by the presence of glassy interfaces ( S < 0 in their vicinity) and the chain-end anchoring junctions ( S > 0).

82.35.Jk - Copolymers, phase transitions, structure.
68.08.-p - Liquid-solid interfaces.
76.60.-k - Nuclear magnetic resonance and relaxation.

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