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Volume 81, Issue 3
Displaying 1-8 of 8 articles from this issue
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[in Japanese]2008 Volume 81 Issue 3 Pages 79
Published: March 15, 2008
Released on J-STAGE: March 25, 2010
JOURNAL FREE ACCESSDownload PDF (119K) -
Shun-ichi OTSUKA, Gentaro TANAKA, Takakazu YAMAMOTO2008 Volume 81 Issue 3 Pages 80-85
Published: March 15, 2008
Released on J-STAGE: March 25, 2010
JOURNAL FREE ACCESSπ-Conjugated polymers are electrically conductive and light-emitting. They are film-forming, and their films possess flexibility and thermostability. They are attracting much attention as future materials for electronic and optical devices. Various π-conjugated conductive polymers have been synthesized via organometallic polycondensations mediated by organotransition metal complexes, and their applications to thin-film-transistors (TFT), organic-light-emitting diodes (OLED), photovoltaic cells, etc. are actively researched.
In this chapter, we describe synthetic methods of π-conjugated conductive polymers using organometallic polycondensations. For example, Ni (0) complex-promoted dehalogenative polycondensation of dihaloaromatic compounds X-Ar-X affords poly(arylene)s —(Ar)n—, and Pd-catalyzed polycondensation gives poly(arylene-ethynylene)s, etc. Applications of conducting polymers to organic-thin-film-transistors and organic-light-emitting diodes are also described.View full abstractDownload PDF (6632K) -
Satoshi OKAMOTO2008 Volume 81 Issue 3 Pages 86-92
Published: March 15, 2008
Released on J-STAGE: March 25, 2010
JOURNAL FREE ACCESSLiquid crystalline polyester (hereafter designated as LCP) represents peculiar physical properties and provides excellent injection moldability for accurate electro and electronic parts, such as connector, relay, bobbin, etc., due to its intrinsic liquid crystallinity.
Recently the market of commercial LCP has been rapidly growing and has shown almost 15% growth of the shipment volume by making good use of the excellent performance. In the future the market is expected to expand more and more rapidly because miniaturization and thin wall moldability of electronic parts still more proceed in the front electro and electric parts fields.
In this review we will proceed from generalities into particulars on liquid crystalline polyesters. The latest situation of research and development of commercial LCP will be reported through not only molecular design and physical properties of our typical LCP product but also introduction of our newly developed isotropic fabrication method such as solvent-casting, micro powder compression, and nano-scale fiber non-woven cloth.View full abstractDownload PDF (12979K) -
Tsuyoshi SHIODA2008 Volume 81 Issue 3 Pages 93-98
Published: March 15, 2008
Released on J-STAGE: March 25, 2010
JOURNAL FREE ACCESSRecent trends for optical circuit using transparent polymer were described. There are two kinds of actual and potential markets for optical circuit. One is an optical component for optical telecommunication, the other is an optical circuit board for data communication. The latter has attractive much attention from the viewpoint of market volume. Not only transparent and thermal stability, but also mechanical properties, such as bending endurance, are required for optical circuit board in order to apply to consumer products, such as mobile. Optical circuit board with new functions, which cannot be predicted at present, would be necessary near future. To commercialize certainly optical circuit board and then expand its markets, optical circuit boards should be developed on appropriate time frame and its timing, taking account of potential needs from customers and standardization strategically.View full abstractDownload PDF (5247K) -
Yoshitaka TAKEZAWA2008 Volume 81 Issue 3 Pages 99-104
Published: March 15, 2008
Released on J-STAGE: March 25, 2010
JOURNAL FREE ACCESSPresent electrical devices have large calorific power, then improvement of heat dissipation has been a very important subject. We developed the novel epoxy resins which increased the thermal conductivity that has been a barrier to heat dissipation. The medium of thermal conduction for insulating resins is phonons. Phonon conduction depends on the crystallinity, since it is a lattice vibration. The scattering of phonons happens at the interface of an amorphous structure. If there is a macroscopic amorphous structure despite the existence of crystal structure on the microscopic level, we expected that high thermal conduction could be attained by reduced scattering of phonons through controlling the nano scale structure. Using an epoxy resin which has the mesogen structure would solve this problem because it's easy to carry out an orientation with this structure. As a result, we confirmed that thermal conductivities become higher when the amounts of mesogens were increased. The conductivity of the developed epoxy resin was about five times higher than that of the conventional epoxy resin.View full abstractDownload PDF (9630K) -
Koji ISHIZU2008 Volume 81 Issue 3 Pages 105-111
Published: March 15, 2008
Released on J-STAGE: March 25, 2010
JOURNAL FREE ACCESSA novel route to hyperbranched polystyrene (HPS) from 4-vinylbenzyl N, N-diethyldithiocarbamate (VBDC) as an inimer by one-pot photopolymerization is presented. This polymerization proceeded by the self-addition living radical mechanism. Statistical branched HPS was prepared by living radical copolymerization of VBDC with styrene under UV irradiation. Hyperbranched poly(ethyl methacrylate) (HPEM) was also prepared by self-addition living radical polymerization from 2-(N, N-diethyldithiocarbamyl) ethyl methacrylate (DCEM). These hyperbranched polymers behaved as hard spheres even in a good solvent and formed a single molecule in solution. Moreover, we have established more complex molecular architectures using inimers as starting materials such as star, star-block, alternating hyperbranched, star-hyperbranched copolymers, and reactive microspheres. For application of functional nano-materials, we demonstrated a new class of holographic recording and structural color films constructed by hyperbranched polymers and reactive microspheres, respectively.View full abstractDownload PDF (9977K) -
Yoshiro KANEKO, Jun-ichi KADOKAWA2008 Volume 81 Issue 3 Pages 112-117
Published: March 15, 2008
Released on J-STAGE: March 25, 2010
JOURNAL FREE ACCESSThe present article briefly reviews recent research developments in the area for production of functional composite materials using biomacromolecules, e. g., polysaccharides, as organic resources. In the first part, we explain fundamental characteristics of cellulose and amylose as abundant organic resources. In the second part, preparation of composites composed of polysaccharides and the other biomacromolecules is described. A film and a hydrogel of cellulose-based composites were prepared by the combination with amylopectin and gelatin, respectively. On the other hand, amylose-based composites were synthesized by the combination with chitin and chitosan using blend and chemoenzymatic synthetic methods. In the third part, we describe preparation of cellulose-based composites combinated with synthetic materials. Transparent cellulose-based composite films composed of bacterial cellulose and thermosetting resins such as acrylic and epoxy resins were prepared. Furthermore, use of ionic liquids efficiently provided various cellulose-based composites combinated with synthetic materials such as polymeric ionic liquids and carbon nanotube.View full abstractDownload PDF (3276K) -
[in Japanese]2008 Volume 81 Issue 3 Pages 118-119
Published: March 15, 2008
Released on J-STAGE: March 25, 2010
JOURNAL FREE ACCESSDownload PDF (261K)
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