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See the article by Tsuyoshi Michinobu, Jun Inui and Hiroyuki Nishide, Two-dimensionally extended organic high-spin poly(aminium cationic radical)s and their magnetic force microscopic images on page 575.
The design and preparation of azobenzene-containing polymers showing a large photoinduced change in refractive index, and their applications to rewritable Raman-Nath and Bragg holograms are reviewed. Holographic performance has been remarkably improved with regard to diffraction efficiency, response time and multiplicity by development of newly designed polymer systems.
Chiral and achiral amine-functionalized norbornene monomers were synthesized and polymerized using 1st Grubbs Catalyst, and the chiroptical properties of the polymers were studied. The tendency to increase the absolute value of specific rotation with an increase in Mn was observed. Using (−)-spartaine (Sp) as a chiral additive, the chiroptical property of the obtained polymer was enhanced in some cases.
The Cp calculation value (♦) of unfreezable bound water in PVME/water mixtures at low temperature. ◊: the experimental Cp of glassy water;21 □: the Cp of cubic ice.30
The defects and heterogeneous system of polyaniline (PANI) doped in benzene sulfonic acid (BSA) with a crystalline region dispersed in an amorphous low-conducting region as shown in the scanning electron microscopy micrograph reveal the current–voltage characteristic, which shows a nonohmic variation. It increases in current with applied voltage owing to the conduction mechanisms of PANI due to the formation of polarons and bipolarons. As the applied voltage increases, the formation of polarons and bipolarons increases rapidly, contributing to higher values of current through sample. This characteristic affects the dielectric behaviors of the elaborate composites.
An ionic liquid (IL), 1-methylimidazolium sorbate (MimS), is designed and subjected to exploration as the modifier to improve the performance of the styrene butadiene rubber (SBR)/silica composites. The significantly improved filler dispersion and the effectively enhanced mechanical properties are ascribed to the changed interfacial structure induced by the functional IL.
The structure of polyethylene/polydimethylsiloxane polymer composites prepared by using supercritical carbon dioxide could be controlled in the depth direction. It depends on the control of the mass gain, namely, the polymerization time.
Time-dependent piezoresistance was investigated as a function of carbon nanotube (CNT) concentration in polyvinylidene fluoride (PVDF)/CNT composites. For quasi-static loading and long-term creep, the electrical response of the composites has been studied. An equivalent Burgers model was used to describe strain dependence and fractional resistivity time dependence. Raman spectroscopy was used to correlate the dispersion of CNT in polymer matrix and resistance response.
High-molecular-weight and soluble two-dimensionally extended aromatic polyamines, prepared by palladium-catalyzed polycondensation, were oxidized to afford the corresponding poly(aminium cationic radical)s, which showed an average spin alignment of 8–9 unpaired electrons at low temperature. The polyradicals were substantially stable at room temperature, which enabled us to visualize the single polyradicals as a nanoscale magnetic dot image by using magnetic force microscopy.
CaCO3/chitin-whisker hybrids were prepared by deposition of CaCO3 crystals in ordered chitin gel matrices. The gels were prepared by conversion of lyotropic liquid crystals of chitin whiskers.
The effect of cooling rate after polymer melting on the electrical properties of high-density polyethylene (HDPE)/Ni conductive polymer composites was investigated. Ni particles in HDPE/Ni composites are localized into the amorphous matrix of HDPE. Therefore, conductive paths are formed effectively by increasing HDPE crystallinity. It was found that the resistivity at room temperature of slowly cooled samples is lower than that of quenched samples because the crystallinity of HDPE in slowly cooled samples is higher than that in quenched samples.
By introducing different notch depths on the width direction of dumbbell samples of PET, the skin-core structure, notch depth and fracture modes of PET are correlated with the crack-tip temperature. The gray and infrared images of samples show the changes in fracture modes and crack-tip temperatures as notches become core deep. Maximum crack-tip temperature occurred because of crazing in a mixed mode of fracture at 1- to 1.5-mm-deep notches (d–f), considered the terminal end of the skin and interface between the skin and core regions.
Reactive extrusion of poly(L-latctide) (PLLA) was carried out in the presence of a small amount of various peroxides. The resulting crosslinked, four-armed randomly branched PLLA (χ-PLLA) was characterized by size exclusion chromatography fitted with multiangle laser light scattering and rationalized with the type of peroxide used. The extent of branching of χ-PLLA was estimated by the shrinking factor and was rationalized with the effective radical number per PLLA precursor n. The nucleation and overall crystallization rate of χ-PLLA in the nonisothermal crystallization from the melt was rationalized with branching and entanglement density.
