Thermoplastic elastomers are elastomeric materials which contain hard domains as physical cross-linking for rubbery chains. Therefore, the hard domains are required permanently rigid. Nevertheless, we have found experimentally deformation of the hard domains upon uniaxial stretching of the thermoplastic elastomer films. In this paper, we report experimental results of deformation of glassy spherical microdomains in elastomeric triblock copolymer films upon uniaxial stretching, as revealed by two-dimensional small-angle X-ray scattering (2d-SAXS) measurements. Actually, shifts of the peak position of the particle scattering toward lower and higher q-regions were detected for q directions parallel and perpendicular to the stretching direction (SD), respectively, where q stands for the scattering vector. By assuming that spheres simply deformed into prolate spheroids with its major axis parallel to SD, 1d-SAXS profiles measured at several strains were successfully reproduced with model calculation of the 1d-SAXS profile. From the results of model calculation, radii of the prolate spheroids were appropriately determined. Since the extent of the deformation of microdomains was found to increase as the initial size of microdomains decreased, it is concluded that the deformation of glassy microdomains may be due to a high extent of the stress concentration at microdomains. Upon unloading, the deformed particle scattering peak in the 2d-SAXS pattern was found to retrieve almost a round shape. At a glance, this fact implies that the deformed sphere (prolate spheroid) recovers an isotropic shape. However, this kind of the elastic behavior cannot be the case for the glassy domain. Alternatively, we have tried to explain the change of the 2d-SAXS pattern by orientational relaxation of the prolate spheroids without changing the shape of the prolate spheroids. It was found that such trial was sound.

A series of novel self-assembling star-blocks consisting of M w = 29 000 g/mol 3-arm polyisobutylene (PIB) stars and oligo(β-alanine) end segments were synthesized and characterized. Star−blocks containing β-alanine dimers are viscous liquids, while those with tri-, tetra-, and penta(β-alanine)s are elastic solids. According to IR spectroscopy, the β-alanine dimer is partially hydrogen-bonded, while the trimer, tetramer, and pentamer are fully hydrogen-bonded and form β-sheets. DSC suggests crystalline β-alanine trimer tetramer and pentamer domains phase separated from the rubbery PIB. The melting temperature of the crystalline domains increases with the length of the oligo(β-alanine) segment. Transmission electron microscopy, wide-angle X-ray diffraction, and small-angle X-ray scattering of star-blocks containing tetra(β-alanine) indicate stacks of hydrogen-bonded β-sheets dispersed in a soft continuous PIB phase. The crystalline phases form fibrous lamellae with lengths up to ∼200 nm, widths up to ∼20 nm, and thicknesses of ∼2 nm, which is the length of β-alanine tetramer. Although the oligo(β-alanine) contents are very low (from 1.5 to 3.6 wt % in the series), the static and dynamic mechanical properties of the star−blocks are very different. The elastic moduli of the TPEs increase 5-fold with increasing β-alanine content. Evidently, the oligo(β-alanine) domains provide not only physical cross-links but also act as fillers.

A metal-lustrous self-standing film, named "porphyrin foil", was formed from a glass-forming polymeric porphyrin. The amorphous glass nature of the porphyrin foil played a key role in spontaneously producing a smooth surface. Its sharp contrast in intense absorption and specular reflection of light at each wavelength provided a brilliant metallic lustre.

We have found extremely low efficiency of the elastomeric properties for SEBS (polystyrene-block-poly­(ethylene-co-butylene)-block-polystyrene) triblock copolymers having short polystyrene (PS) block chains. Since the SEBS specimens form spherical PS microdomains embedded in the matrix of the rubbery poly­(ethylene-co-butylene) (PEB) chains, they exhibit elastomeric properties (thermoplastic elastomer film). However, it was found that the stress was dramatically decreased with time when the specimens were stretched and fixed at strain of 4.0. Furthermore, they showed macroscopic fracture with very short-term duration (400 s to 2 h). To reveal the reason for such low efficiency, we conducted time-resolved two-dimensional small-angle X-ray scattering (2d-SAXS) measurements for the SEBS triblock copolymer films under stretched state at strain of 4.0. Upon stretching, the strain-induced deformation (not fracture) of glassy microdomains was observed. In addition, the deformation of glassy microdomains was found to proceed as time elapsed. Since this deformation of the glassy PS microdomains is considered to result in such the low efficiency of the elastomeric properties, characteristic times related to the deformation and the stress relaxation were evaluated from the change in strain of the glassy microdomains and from the stress relaxation curves, respectively. Then, good agreements of the characteristic times were found, and therefore it was concluded that the deformation of the glassy microdomains has a strong correlation with the stress relaxation and therefore with the fracture of the elastomeric film specimen.

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