Europhys. Lett., 62 (5) , pp. 746-752 (2003)
Heterogeneity of the chain segment dynamics and ordering in lamellar layers of a symmetric triblock copolymerC. 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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