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Predecessor
Volume 35, Issue 9
Displaying 1-9 of 9 articles from this issue
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Yasuji OHTSUKA, Akira HIROSAWA1978 Volume 35 Issue 9 Pages 535-542
Published: September 25, 1978
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSLight-focusing plastic rods (LFR) having parabolic refractive index distributions were fabricated by the following two-step copolymerization technique. Diallyl phthalate (DAP) containing benzoyl peroxide (BPO) was polymerized partially in a casting polypropylene tube to yield a DAP prepolymer gel rod (GR). The GR thus formed was immersed in methyl methacrylate (MMA) containing BPO under various conditions. After draining off MMA liquid, the rod was heat-treated in order to complete the copolymerization. The relations between both 2θ (acceptance angle of LFR) and ΔW (weight increment in the immersion process) and the fabrication conditions (composition of GR, BPO concentration, immersion temperature, immersion time, etc.) were explained qualitatively in terms of diffusibility of MMA monomer in GR and fixation of MMA unit by the copolymerization of MMA with allylic compound in GR. The overall chemical composition, the radial distribution of copolymer composition, the gradient constant of refractive-index, and the lens function for the representative DAP-MMA LFR were also shown.View full abstractDownload PDF (1609K) -
Yukio UEMURA1978 Volume 35 Issue 9 Pages 543-549
Published: September 25, 1978
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe influence of V-notch shapes of test specimens on the Charpy impact values of two kinds of plastics, i. e. PMMA and PP, was studied experimentally. The expriments were carried out by taking seven steps of notch root radius over the range of 0-2.0 mm and ten steps of notch depth over the range of 0.1-5.0 mm. The Charpy impact values were affected seriously by the notch shapes, and the values ranged from 1.2 to 13.2 kgfcm/cm2 for PMMA and from 1.6 to 46 kgfcm/cm2 for PP. The Charpy impact values increase with increasing notch root radius and decreasing notch depth. A close relationship has been found between the Charpy impact values and the modes of fractured surfaces of broken specimens.View full abstractDownload PDF (2781K) -
Naoya OGATA, Kohei SANUI, Takao ONOZAKI1978 Volume 35 Issue 9 Pages 551-557
Published: September 25, 1978
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSInterfacial copolycondensation of p-phenylenediamine (PPD) and m-phenylenediamine (MPD) with isophthaloyl chloride (IPC) has been carried out by using two immiscible organic solvents. Effects of solvent systems, acid acceptors and additives on the interfacial copolycondensation have been investigated in terms of yields, solution viscosities, compositions and sequence distribution of resulting copolymers. Solution viscosities, compositions and sequence distribution of the copolymers were not influenced by solvents, while polymer yields were affected by acid acceptors. That is, organic acid acceptor gave polymer in a good yield, while inorganic one produced polymer in a poor yield, in contrast with the case of interfacial polycondensation using an aqueous phase. It was found that polymer yields increased when potassium hydroxide included by 18-crown-6 was used as an acid acceptor.View full abstractDownload PDF (1095K) -
Kenji SATO, Kazuhiro MARUYAMA, Masakazu YAYOSHI1978 Volume 35 Issue 9 Pages 559-564
Published: September 25, 1978
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe kinetics and mechanism of the acid-catalyzed hydrolysis of trimethylolmelamine (M3F) to dimethylolmelamine in 30-vol% dimethyl sulfoxide aqueous solution have been studied. At a constant pH, the reaction was of ca. 1.5 order in [M3F] 0, and the pseudo-first-order rate constants, kobsd, determined for the reactions at pH>2.3 apparently saturated when they were plotted against [M3F] 0. The results were kinetically analyzed on the assumption that M3F (base species) and its conjugate acid HM+3F acted as a general base catalyst and general acid catalyst, respectively.View full abstractDownload PDF (983K) -
Seiji WATATANI, Kenji SUMIYA, Fumitada HAYAMA, Hiromitsu NAONO, Tsunet ...1978 Volume 35 Issue 9 Pages 565-571
Published: September 25, 1978
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe adsorption behavior of water molecules and methyl methacrylate-functional monomer copolymers on γ-Fe2O3 was studied to clarify the interaction between various polymers and γ-Fe2O3 in the magnetic composite. It was quantitatively confirmed that water molecules were chemisorbed and physisorbed on the surface of γ-Fe2O3. Adsorption isotherms of various copolymers on γ-Fe2O3 were clasified as Langmuir type and the saturation adsorbance linearly related to the interfacial tension of copolymers at the water-benzene interface. In this case, the effect of functional groups on the interaction between γ-Fe2O3 and polymers or between water and polymers increased in the order of -COOH, -OH, -N<, and -C-C¥O/≈-CN. Furthermore, this effect of functional groups was recognized in the squareness ratio of magnetization hysteresis curves of magnetic tapes using these polymers as binders.View full abstractDownload PDF (1175K) -
Yasuo MURATA, Masao SUMITA, Keizo MIYASAKA, Kinzo ISHIKAWA1978 Volume 35 Issue 9 Pages 573-579
Published: September 25, 1978
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe relations between the mechanical properties of Kevlar [poly (p-phenyleneterephthalamide)] fibers and the crystallinity and orientation is investigated. Film specimen with different crystallinity and molecular orientation were prepared by casting sulfuric acid solution of poly (p-phenyleneterephthalamide) on a glass plate and by subsequent drying in which molecular orientation is indirectly controled. Initial Young's modulus, breaking strength and elongations were measured for these samples and the results were discussed in relation to the orientation functions Fc of crystallites and crystallinity X determined by Ruland's X-ray method. The observed density of amorphous region of Kevlar fibers were about 1.340 gr/cm3, assuming additivities of specific volumes of crystalline and amorphous regions. The Young's modulus and the breaking strength increased with increasing Fc and X. Young's modulus Y can be represented empirically by the following equation not only for our specimens but also for Kevlar fiber.
log Y=2.43+0.004X+1.6Fc2
A similar equation for breaking strength of specimen fails to predict the breaking strength of Kevlar fibers, suggesting that the breaking strength of specimen is determined not only by crystallinity and orientation but also by other factors.View full abstractDownload PDF (1237K) -
Yuki SEKIGUCHI, Taichi OGAWA, Takeshi KUROKI, Tadashi IKEMURA1978 Volume 35 Issue 9 Pages 581-586
Published: September 25, 1978
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThermal degradation of polystyrene was kinetically investigated with special reference to the formation rates of monomer, dimer, trimer and wax-like compounds. The degradation was carried out under an atmospheric pressure and at 360-420°C in a flow reactor. The results indicate the degradation consists of consecutive-simultaneous reactions as shown below, each of which is first order in polystyrene concentration.
Polymer→Low molecular weight polymer
k1→Monomer
k2→Dimer
k3→Trimer
k4→Wax-like compounds
Rate constants for the overall and each of the above reactions were determined.View full abstractDownload PDF (913K) -
Yoshinobu ABE, Ryuichi SAKAMOTO1978 Volume 35 Issue 9 Pages 587-593
Published: September 25, 1978
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSDynamic mechanical properties and differential scanning calorimetries of poly (ethylene terephthalate) (I) fibers were studied in the process of aminolysis with 60% aqueous solution in ethylamine. The intensity and the temperature of the maximum tan δ peak decreased in the initial period of the aminolysis. This phenomenon can be explained by the decrease of the amorphous region of the PET fiber by decomposition and dissolution. After a long period of the aminolysis, the intensity of tan δ maximum peak again increased. This phenomenon could be explained by the disordering of the molecular chains on the crystallite surfaces by decomposition. The double melting peaks were observed for the aminolyzed I fibers. It could be considered that the melting peak at the lower temperature corresponds to the melting of the skin and the peak at the higher temperature to the melting of the core. The differences in the heat of fusion, the melting temperature and the crystallinity may be due to the difference of the surface free energies in the skin and in the core.View full abstractDownload PDF (1184K) -
Kenji IWAKURA, Shinichi SUTO, Toshikazu FUJIMURA1978 Volume 35 Issue 9 Pages 595-598
Published: September 25, 1978
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSIn order to reinforce the coupling between polyolefins and cellulosic fillers, cellulose surface was modified either by substituting the hydroxy groups or by impregnating the cellulose with an ethylenetype copolymer. The interaction at the interface between the matrix polymer and the filler was discussed in terms of the shear strength and of the tensile properties of the composites. (1) Shear strengths between polyethylene and cellophane and between polyethylene and rice-straw were increased by the acetylation of cellulose nearly the same extent as by the impregnation. (2) The Young's modulus and the tensile strength of the composite were also increased by the both treatments of the fillers. (3) Such treatments as to reduce the polarity of cellulose surface would increase the interaction between polyolefin and the filler, being effective for the enhancement of the coupling effect.View full abstractDownload PDF (565K)
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