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Volume 60, Issue 2
Displaying 1-7 of 7 articles from this issue
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Shingo HADANO, Kenjiro ONIMURA, Hirohito YAMASAKI, Hiromori TSUTSUMI, ...2003 Volume 60 Issue 2 Pages 51-56
Published: February 25, 2003
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSBenzylated waste pulps (PBzs) were synthesized from treated waste pulp (Pulp) and benzyl chloride with a phase transfer catalyst (PTC) such as tetramethylammonium iodide. PBzs with higher degree of substitution (DS) than 1.4 showed Tg and Tm. The solubility of PBzs increased with increasing DS, and the crystallinity of PBzs decreased with increasing DS because of hydrophobicity and the steric effects of benzyl groups. A biodegradation test for PBzs (DS=0.83, 1.78 and 2.53) and Pulp was performed using cellulase in 0.1 M acetic acid buffer solution (pH 5.5) at 37°C. All PBzs showed biodegradability, though the biodegradation rate decreased with increasing DS. Thus, PBz can be applied as a biodegradable material.View full abstractDownload PDF (1123K) -
Tasuku YOTORIYAMA, Yoshiaki SUZIJKI, Takeyo TSIJKAMOTO, Masaya IWAKL2003 Volume 60 Issue 2 Pages 57-63
Published: February 25, 2003
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSWe performed ion-beam irradiation of biodegradable polymer sheets to develop a thin film and a self-assembly cellular sheet, which exfoliated spontaneously from the substrate in a water solution. Poly-L-lactic acid (PLLA) sheets were used as substrates. We performed He+ and Kr+ ion-beam irradiation at energies of 50, 100 and 150keV with fluences between 1×1014 and 1×1015ions/cm2. He+ ion-beam irradiation formed a thin film at an energy of 50keV with a fluence of 1×1015ions/cm2 and a thickness of 500nm. Kr+ ion-beam irradiation did not form a film. Simultaneous He+ and Kr+ ion-beam irradiation improved cell attachment properties. We obtained self-assembly cellular sheets by combining these two techniques. The film thickness can be controlled by controlling the ion species and acceleration energy. The experimental values agreed well with the theoretical results. This technique should be useful for new medical devices.View full abstractDownload PDF (2748K) -
Toshio OGAWA, Toshihiro YAMAGATA, Takami HARA, Satoshi OSAWA, Yasunori ...2003 Volume 60 Issue 2 Pages 64-70
Published: February 25, 2003
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThe component of ozone-deteriorated NBR sheets containing additives was analyzed by the pyrolysis gas chromatography/mass spectrometry (Py-GC-MS) method. There were three peaks related to antioxidant in the pyrogram of each NBR sheet. In this study we noticed especially the quinoline type antioxidant. We examined the relationship between the decrease of the antioxidant and the mechanical strength of the sheet. The mechanical strength of NBR sheet surface layer (0.1mm) became zero when the content of this antioxidant reached 50% or less.View full abstractDownload PDF (1811K) -
Nozomu Suzum, Yoko HAYAKAWA, Shigeyuki ONO, Masayoshi ITO2003 Volume 60 Issue 2 Pages 71-77
Published: February 25, 2003
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThe formation mechanism of bound rubber in the composites prepared from precipitated silica and nitrile butadiene rubber (NBR) was studied as a function of nitrile group content of NBR. At a given molecular weight, the amount of bound rubber and the averaged size of agglomerate formed by silica particles in the composites decreased gradually with increasing the nitrile group content of NBR. Infra-red spectra of the samples suggested the existence of hydrogen bonding between silanol groups on the silica surface and nitrile groups in NBR. The hydrogen bonding might suppress the development of agglomerates formed by silica particles, leading to the decrease in the amount of filler-gel entrapped in the agglomerate.View full abstractDownload PDF (2787K) -
Improvement of Weld Strength and Flame RetardancyItaru NATORI, Junichi NAKAHASHI2003 Volume 60 Issue 2 Pages 78-83
Published: February 25, 2003
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThe preparation and properties of polyamide 66 (PA 66) /brominated polystyrene (BrPS) alloy were investigated. Brominated polystyrene modified by maleic anhydride (MA-BrPS) was synthesized by the addition reaction of BrPS and maleic anhydride (MAH) with peroxide. The miscibility of PA 66/BrPS alloy was affected by the content of MAH group in MA-BrPS. The tensile strength (TS) and tensile elongation (TE) on the weld portion of the test piece of PA 66/BrPS alloy were remarkably improved by controlling the particle size of MA-BrPS in PA 66 matrix. The flame retardancy of PA 66/BrPS alloy was also improved by polymer-alloy technique. Finally, the optimum composition of PA 66/MA-BrPS is proposed as a new flame-resistant PA 66 resin with the high weld strength and flame retardancy.View full abstractDownload PDF (1803K) -
Kiyohiro TAKACHI, Tatsuo TANIGUCHI, Seigou KAWAGUCHI, Katsutoshi NAGAI2003 Volume 60 Issue 2 Pages 84-91
Published: February 25, 2003
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThis paper describes syntheses of novel comb-shaped polymeric surfactants (PUSs) with polyurethane chain as the backbone and dodecyl and polyethylene glycol (PEG) groups as the side chains. The estimation of surface-active and micelle-forming properties of the PUSs in aqueous media was completed. Aqueous solutions of the PUSs with low contents of dodecyl chain exhibited cloud points at 60 to 80°C, but those of the PUSs with high contents did not show such points below 100°C. Surface activity of the PUSs was the highest at 17 mol% dodecyl chain to total side chains, within the results obtained in this study, and this activity become lower at higher contents of dodecyl chain. Micelle formation of the PUSs occurred above their critical micelle concentrations, which decreased with increasing the content of dodecyl chain. Reduction of surface activity at higher content of dodecyl chain in PUSs can be ascribed to the fact that the micelle formation of PUSs preceded their adsorption at air/water interface.View full abstractDownload PDF (1474K) -
Polymerization of Cyclic Conjugated Dienes Using Rare-Earth Metal CatalystsItaru NATORI2003 Volume 60 Issue 2 Pages 92-94
Published: February 25, 2003
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThe polymerization of 1, 3-cyclohexadiene (1, 3-CHD) using rare-earth metal (REM) catalysts was investigated. The neodymium (III) isostearate (Nd (ISA) 3) /modified methylaluminoxane (MMAO) /ethylaluminum sesquichloride (EASC) catalyst system could polymerize 1, 3-CHD by coordination polymerization. The activity of various rare-earth elements in REM (ISA) 3/MMAO/EASC catalyst systems for polymerizing of 1, 3-CHD was found to increase in the order of neodymium (Nd), cerium (Ce), gadolinium (Gd), samarium (Sm), and ytterbium (Yb). These catalyst systems have a potential to develop new types of hydrocarbon polymers containing six-membered rings in the main chain.View full abstractDownload PDF (518K)
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