Volume 47 Issue 5, May 2015

A series of novel fluorene-based cardo polycarbonates was synthesized by the anionic ring-opening polymerization of six-membered spirocyclic carbonate monomers. The polymers possessed a fluorene skeleton placed perpendicularly to the main chain. The polymerization of the fluorene monomers progressed according to their solubility in the reaction solvent. Interestingly, the fluorene pendant polycarbonates were obtained in sufficiently high molecular weights and in good yields, in spite of the fact that the monomers are structurally closely related to the diphenyl-substituted cyclic carbonate, which exhibited very low polymerizability. All obtained polymers showed favorable properties, including good solubility, amorphous nature, favorable thermal stabilities, remarkably low birefringence values and high refractive indices despite of the polymer consisting only of C, H and O atoms. The good potentiality in the application to optical materials was shown here.

Disubstituted p-dibromobenzenes having alkoxy groups polymerized to give relatively high molecular weight polymers (M_n=14 700–49 600) in good yields. Polymers exhibited high thermal stability, and the decomposition temperatures were higher than 350 °C. From the differential scanning calorimetry thermograms, polymers showed melting of crystallites or glass transitions. The free-standing membranes could be prepared by the hot-press method. The membrane possessing hexyl side chains exhibited relatively high gas permeability, and the oxygen permeability coefficient was 25.6 barrer, higher than those previously reported for poly(p-phenylene)s having ester substituents.

The conformational convergent calculations of alanine oligomer (2- to 7-mer) were performed by QCC in the order starting from 2-mer (4 × 164 kinds). The ϕ/ψ of 4- to 7-mer was converged to three types; α-helix (g+/g+ or g−/g−), PPII-like (g+/g− or g−/g+) and β-extended (t+/t− or t−/t+), in lower energy order. PPII-like was different from the PPII (g−/t+) reported, and considered to be 2.2₇ ribbon . The energy differences in left- and right-handed ‘methyl type’ of end group were found.

The degree of crystallinity (φ) in interpenetrating spherulites, whereby spherulites of one component continue to grow inside those of the other component, was examined for the blends of poly(ethylene succinate) (PES) and poly(ethylene oxide) (PEO) using pulsed nuclear magnetic resonance. The crystallization temperature influenced the time ranges of the primary crystallization. The value of φ for PES and PEO exhibited different dependence on the blend composition. These results are discussed on the basis of the change in temperature at which the molecular transport is frozen with the blend composition.

We investigated the temperature-dependent domain spacing of lamella-forming polystyrene-block-polyisoprene (PS-b-PI) with different molecular weights, swollen with solvent mixtures consisting of a PS-selective solvent, dimethylphthalate, a PI-selective solvent, n-tetradecane and a neutral solvent, di-n-octylphthalate. The domain spacing showed stronger temperature dependencies than a neat diblock copolymer. The dependencies varied widely with the polymer concentration and solvent composition. The reflection peaks for a solution of the higher molecular weight PS-b-PI were astonishingly tunable over wavelengths between 836 and 377 nm in the temperature range from 20 to 80 °C.

Cell effects on collagen fiber formation in hydrogels and on cell surfaces were characterized at the molecular level.

In the cross-sectional view of sealing gasket, the urethane sealing gasket is composed of urethane-based polymer as a matrix and heat-expandable hollow particles as independent air bubbles. The polyurethane matrix has a crosslinking structure with aliphatic diisocyanate aduct, PTMG, and bi- and trifunctional polyester pre-polymers. Not only by adjusting the mechanical properties with the blowing agent but also by being localized lubricants with talc on the surface, both excellent sealing and opening properties could be realized.

The emulsion formation and the subsequent phase-separation process of water/toluene mixtures has been investigated by employing a pair of block copolymer surfactants having a linear A-B-A and its cyclized A-B topologies. The linear surfactant was found to be more effective to keep the emulsion layer in the water phase, attributable to the folding/extending motion of the hydrophobic A segments specifically in the linear surfactant.