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Volume 43, Issue 3
Displaying 1-9 of 9 articles from this issue
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Yuji FUJITA, Kong-Khen KOO, Juan Carlos ANGOLA, Takashi INOUE, Tetsuya ...1986 Volume 43 Issue 3 Pages 119-131
Published: March 25, 1986
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSA polymer blend of ductile polymer with brittle polymer, e. g., polycarbonate (PC) with poly (styrene-co-acrylonitrile) (AS), is a new way to design toughened plastics. Both the stiffness and the toughness of ductile polymer can be improved by inclusion of the brittle polymer particles. In order to find out new combinations similar to PC/AS, we investigated mechanical properties of various blends consisting of ductile and brittle polymers. Among them, new 6 combinations were found to be the toughened blends. The toughening seems to be a rather general phenomenon for some class of brittle/ductile combinations. Morphological studies by SEM and TEM revealed the cold drawing mechanism of brittle polymer particles, by which the impact energy is absorbed to improve the toughness. Analysis of stress concentration on the dispersed particles was undertaken by using the modified Eshelby theory. The cold drawing of brittle polymer particles can be well described in the framework of Mises' condition for yielding. These suggest a potential for semi-quantitative prediction of the development of toughening by means of material constants, such as Young's moduli, Poisson's ratio, and brittle-to-ductile transition pressure (or Mises' k).View full abstractDownload PDF (4256K) -
Katsuhiko NAICAMAE, Takashi NISHINO, Katsuhiko HATA, Tsunetaka MATSUMO ...1986 Volume 43 Issue 3 Pages 133-138
Published: March 25, 1986
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe temperature dependence of the elastic modulus E1 of crystalline regions of poly (vinyl alcohol) (PVA) in the direction parallel to the chain axis has been investigated by X-ray diffraction. The value of E1 for the (020) plane of PVA was 235 GPa from room temperature to 110°C. However, it decreased abruptly near 110°C, and was 167 GPa at 180°C. The lattice spacing of the (020) plane decreased with increasing temperature up to 180°C. This means that molecular contraction occurs at high temperature. Further, this change is more pronounced in the higher temperature range. The thermal expansion coefficient α (020) changes discontinuously aroun4 110°C (<110°C; α (020) =-3.3×10-6K-1, >110°C; α (020) =-9.9×10-6K-1). These phenomena and the results of dynamic mechanical measurements and infrared spectroscopy show that the mobility of chain molecules in the crystalline regions, i. e., incoherent thermal vibration of crystal lattice, increases beyond 110°C, and that this causes the decrement of E1 at high temperature.View full abstractDownload PDF (1575K) -
Hiroshi FUJIWARA, Akio SUGISHITA, Sakunobu KANAI, Yoichi OHNO, Hiroaki ...1986 Volume 43 Issue 3 Pages 139-146
Published: March 25, 1986
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSIn order to prepare porous copolymer beads with high reactivity, suspension copolymerization of p-vinyl-phenyl acetate (p-VPOAc) and divinylbenzene (DVB) was carried out. Isooctane-2-ethyl-1-hexanol (3: 7 wt/wt) mixture was chosen as an efficient diluent for the formation of porous copolymers. Effects of various factors such as amount of the diluent, monomer composition, initiator concentration, and reaction temperature on the formation of porous structure in the copolymers were investigated. It was found that the surface areas or the porosities of the copolymers were very sensitive to the amount of the diluent and the monomer composition. Both of the surface area and the porosity increased with increasing content of DVB at the optimum ratio (1: 1 wt/wt) of the diluent to the p-VPOAc-DVB mixture.View full abstractDownload PDF (1603K) -
Makoto YAMAMOTO, Tatsuaki YAMAGUCHI1986 Volume 43 Issue 3 Pages 147-151
Published: March 25, 1986
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSProgressive degradation was carried out for poly (vinyl chloride) (PVC) film, polyethylene (PE) film and a commercial agricultural PVC film; a carbon-arc weathering tester was used. As the polymer chain of PVC reacted with oxygen to form α, β-unsaturated carbonyl group, the elongation at rupture and the tensile strength of the degraded PVC film decreased at the initial period of the exposure. But with increasing the exposure time, the tensile strength increased because of the formation of crosslinkage. On the other hand, the depression of the mechanical properties of the commercial agricultural PVC film was mainly due to the volatilization of the plasticizer. As the crosslinkage in PE film was actively formed after 300 h exposure, the tensile strength increased with increasing the exposure time even though the formation of carbonyl groups also increased.View full abstractDownload PDF (877K) -
Hideo SAEKI1986 Volume 43 Issue 3 Pages 153-160
Published: March 25, 1986
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe relation of monomer ratios in poly (methyl methacrylate-co-t-butyl methacrylate) s to electron beam sensitivities and thermal properties of the heat-treated copolymers was investigated in order to develop a highly sensitive positive electron beam resist. These copolymers sustained weight loss as a result of heat-treatment at 250°C and the evolved gases during this heat-treatment were mainly composed of isobuten. Therefore this weight loss was due to elimination of the t-butyl groupsfrom the t-butyl methacrylate component in the copolymers. Cyclized acid anhydrides mainly formed on such portions of the heat-treated copolymer films. The glass transition temperature of the copolymers increases as a result of the heat-treatment, so that thermal stabilities were improved, with a higher content of t-butyl methacrylate in the copolymers. In these copolymers, a 37 mol%. composition of t-butyl methacrylate, designated CP-3-2, showed the highest sensitivity (0.35 μC/cmcm2) and a high γ-value (1.9). Moreover, the CP-3-2 resolved a micro circuit pattern (less than 1.0μm line width), and the resistance to dry etching of the CP-3-2 are higher than the values for poly (methyl methacrylate). It is clear that CP-3-2 has a higher performance for highly sensitive positive electron beam resist.View full abstractDownload PDF (1950K) -
Hitoshi CHAWANYA, Naoki TOSHIMA, Hidefumi HIRAI1986 Volume 43 Issue 3 Pages 161-164
Published: March 25, 1986
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSColloidal palladium with an average diameter of 18Å was prepared by reducing palladium (II) chloride with methanol in the presence of poly (N-vinyl-2-pyrrolidone). The colloidal palladium exhibited high activity as a catalyst for hydrogenation of 1, 5-, 1, 4-, 1, 3-, and 2, 4-hexadiene. The hydrogenation produced the corresponding monoene at high selectivity. Examination of the isomer distributions of the produced monoene showed that isomerization of monoenes was prohibited in the presence of dienes. The hydrogenation of conjugated diene proceeded through both 1, 2- and 1, 4-addition. The ratio of 1, 2- to 1, 4-addition depended on the structure of the dienes.View full abstractDownload PDF (633K) -
Yoichi OHNO, Hiroshi FUJIWARA, Kinya TAWARA1986 Volume 43 Issue 3 Pages 165-168
Published: March 25, 1986
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSPorous copolymer beads of p-vinylphenyl acetate (p-VPOAc) and divinylbenzene (DVB) were prepared by suspension copolymerization in the presence of isooctane and 2-ethyl hexyl alcohol mixture as diluent. Porous copolymer beads of p-vinylphenol (p-VP) and DVB were prepared by hydrolysis of the above copolymer beads and then were nitrated. Their structures were examined by infrared spectroscopy. These porous copolymer beads had good performance and separation characteristics as high-performance liquid chromatographic packings for various organic compounds.View full abstractDownload PDF (607K) -
Nobuhide YAHIRO1986 Volume 43 Issue 3 Pages 169-172
Published: March 25, 1986
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSStereo-differentiation reactions of various racemic oxiranes were investigated by using optically active aziridines and polyaziridines. When (S) -aziridines were used as base reagents, the sign of the recovered oxiranes was negative rotation, showing predominant consumption of (R) -oxirane. On the other hand, for (S) -polyaziridines as base reagents, the recovered oxiranes showed a positive rotation. The influence of steric hindrance between oxirane and the polymer upon the stereoselective consumption of (S) -oxirane was examined.View full abstractDownload PDF (696K) -
Tomohiro KURAMOCHI, Hiroshi SHIMURA, Masaru IBONAI1986 Volume 43 Issue 3 Pages 173-176
Published: March 25, 1986
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSChlorinated polyethylenes having acrylamide units as pendants (CPE-AAm, degrees of substitution=8.5 and 15.5) were prepared by the reaction of chlorinated polyethylene (CPE) with acrylamide using amines as catalysts. Grafting in the graft polymerization of styrene onto CPE-AAm with AIBN as initiator was higher than that in the graft polymerization of styrene onto CPE polymer without acrylamide residues. At the concentration 2 mol/l of styrene, grafting for CPE-AAm was about 10 times as large as the value for CPE.View full abstractDownload PDF (596K)
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