H-2 NMR-STUDY OF THE LOCAL UNIAXIAL ORDER IN DEUTERIUM-PROBED BLOCK-COPOLYMER SUBLAYERS

Deuterium NMR spectroscopy (H-2 NMR) has been applied in studying the molecular dynamics in lamellar microdomains of polystyrene-polybutadie ne (PS-PB) diblock copolymer. Perdeuterated polybutadiene homopolymer chains of low molecular weight were incorporated in lamellar PS-PB cop olymer matrix and used as NMR probes. H-2 NMR spectra show clearly a s ignificant motional anisotropy of the probe chains, indicating that th e segmental dynamics is uniaxial around the axis normal to the sublaye rs. This uniaxial order of the probe chains reveals the uniaxiality of the copolymer matrix and shows that the PB chains are slightly elonga ted.