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Lamellar diblock copolymers are investigated under large amplitude oscillatory shear (LAOS) at temperatures close to the order–disorder transition temperature (TODT). Increasing strain amplitude leads to a double flip of orientation. The state of orientation depends on an effective shear rate as in similar experiments on lyotropic lamellar phases.

The temperature dependance of the proton NMR line shape, T1 and T1ρ of isotactic poly‐1‐butene forms I, I′, II, and III have been studied between 100 and 400 K (up to melting). The usual line shape decompositions concerning rigid vs. crystalline and mobile vs. amorphous phases are discussed. The rigid‐lattice second moments were calculated introducing a fast rotation of the methyl group. Complex spin‐lattice decays were analyzed as a continuous distribution of rates. Relaxation behavior was analyzed in terms of a Williams‐Watt correlation function. Motions in the crystalline parts of samples in forms II and III very similar to the amorphous one were revealed, leading us to compare form II to a condis crystal during the crystal form transformation. © 1995 John Wiley & Sons, Inc.