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Volume 33, Issue 8
Displaying 1-10 of 10 articles from this issue
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Susumu KAWASE, Takashi FUKUTOMI, Toshio KAKURAI1976 Volume 33 Issue 8 Pages 421-426
Published: August 25, 1976
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe mechanical scission of styrene-methyl methacrylate block copolymers in the dilute solutions at early stage of the degradations were studied by using high speed stirring and ultrasonic irradiation. Two kinds of block copolymers having different molecular weights and compositions were prepared and three kinds of solvent systems (toluene, toluene-cyclohexane, toluene-acetonitrile) were used. The degraded block copolymers were separated to two parts of homopolymers and a block copolymer. The weight fraction and the composition of each polymer were measured and the molecular weight distribution was determined by gel permeation chromatography. From the results of these measurements it was revealed that the chain scission occured widely on the methyl methacrylate segment of block copolymers at the first stage of the degradation in each solvent system and the influence of solvent systems on the mechanical scission of block copolymers was remarkable to the styrene segment compared with the methyl methacrylate segment.View full abstractDownload PDF (1267K) -
Katsuyoshi IISAKA1976 Volume 33 Issue 8 Pages 427-431
Published: August 25, 1976
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSDynamic mechanical properties of poly (methyl methacrylate) (I) filled with glass beads (G) and mica (M) of various size have been investigated. Dynamic modulus E′ slightly decreases with the increase of particle size for I-G system, but E rapidly increases and then attains to the upper limitting value with the increase of particle size for I-M system. With increasing particle size, primary dispersion temperature (Tα) decreases for I-G system, but increases for I-M system. Effect of particle size on the modulus can be explained in terms of orientation of mica flakes by comparing the experimental data with Wu' and Padawer and Beecher's predictions of the modulus. The observed results of Tα have been analysed by using the equation Tα=K1 ln K2S, where S is a surface area of filler per gram of polymer matrix, and K1 and K2 are constants. It has been found that Tα is strongly affected by the surface area of the filler in the case of I-G system and affected also by the orientation effect in addition to the surface area of the filler in the case of I-M system.View full abstractDownload PDF (946K) -
Kuniyoshi ITOYAMA1976 Volume 33 Issue 8 Pages 433-439
Published: August 25, 1976
Released on J-STAGE: March 25, 2010
JOURNAL FREE ACCESSFrom the analysis of angular dependence of the line shape and the second moment in NMR spectra of drawn poly (ethylene terephthalate) films, the following results have been obtained. 1) The orientation parameters which characterize the molecular orientation have been estimated for uniaxially drawn films. Those parameters for a 5.0 draw ratio film are shown to be consistent with those derived from pseudo-affine deformation model, but those for a 7.0 draw ratio film deviate from those values of the model. 2) With the approximation that the magnetic anisotropy arises only from the nearest proton pairs in a molecule and the magnetic interactions from other proton pairs are isotropic, line shapes and second moments for different structural models have been calculated. By comparison of the observed data with the calculated values, a semiquantitative measure of the orientation of the molecules was obtained, and it was shown that a biaxially drawn film exhibits approximately a preferred planar orientation in which the molecules are inclined to the plane of the film by an angle of 27-29°.View full abstractDownload PDF (1249K) -
Kuniyoshi ITOYAMA1976 Volume 33 Issue 8 Pages 441-447
Published: August 25, 1976
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSA wide-line NMR study of molecular motion in poly (ethylene terephthalate) (I) has been made on a uniaxially and biaxially drawn film. The anisotropy in the NMR second moment of I, taking the distribution of molecular orientation into account, has been calculated for several models of molecular motion, in which it is assumed that benzene rings and methylene groups are static or in freely rotational motion about the molecular axis. Calculated second moments are compared with the observed values for uniaxially drawn films. At 170°C, the methylene groups in the oriented regions undergo a hindered rotation about the molecular axis. At about 20°C, the transition of the line width which is observed clearly for a 5.0 draw ratio film, is shown to be related to the rotational motion of the methylene groups and this transition becomes less clear in a 7.0 draw ratio film. For a draw ratio of 7.0, molecular chains in the oriented regions appear to be almost static at 20°C. For a biaxially drawn film, the motional transitions observed at 100-120°C and at 110-150°C are due to the methylene groups and the benzene rings in the chains, respectively, and the molecular orientation in oriented regions is maintained to a considerable extent even at 170°C.View full abstractDownload PDF (1216K) -
Hisashi YOSHIOKA, Chieko MIYAMOTO, Kazuhiro OMATA, Fukuji HIGASHIDE1976 Volume 33 Issue 8 Pages 449-452
Published: August 25, 1976
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSPermeability of oxygen to PMMA films prepared by photopolymerization in the presence of flaky glasses as fillers was measured to know how the way of their preparation affects on the permeability. The permeability of the films prepared by such a way is lower than that prepared by evaporation of solvent. Furtheremore, the treatment of flaky glasses in high-frequency plasma of MMA monomer before photopolymerization lowered the permeability. This method was shown to be one of excellent techniques for surface treatment. A few points of these results were discussed analytically.View full abstractDownload PDF (818K) -
Kozo KATAOKA, Ichitaro UEMATSU1976 Volume 33 Issue 8 Pages 453-462
Published: August 25, 1976
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSTo make clear the conformation of fibroin in the liquid silk (silk gel, water content 75-77%) of the matured silkworm (Bombyx mori), the liquid silk was pressed (pressing velocity 0.5-500 mm/min) and then dried at room temperature. In case of pressing velocity 0.5 mm/min, the conformation of the silk fibroin continuously changed into α-form→amorphous→β-form with increasing pressing ratio. The β-form was obtained by press deformation of liquid silk. On the α-form and amorphous, the conformational change was investigated from the drying process of various relative humidity. It is confirmed that the conformation of fibroin in the liquid silk is random coil. There is random coil→α-form transition in the region of water content 20-70%. In the drying process, occurrence of this transition depends on the time for passing in the region of water content 70-70%.View full abstractDownload PDF (3407K) -
Sung Sun IM, Keizo MIYASAKA, Kinzo ISHIKAWA1976 Volume 33 Issue 8 Pages 463-469
Published: August 25, 1976
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe structure and properties of anisotropic polymeric composite material prepared by uniaxial drawing were studied for polypropylene filled with metallic glass particles. The effects of filler on the draw ability, Young's modulus and chain molecular orientation of polypropylene were measured. Draw ratios in necking part monotonously decrease with increasing filler contents. Young's modulus in the direction of fiber axis becomes smaller with increasing filler contents in the drawn composite. And degree of molecular orientation of the amorphous region in polymer matrix is strikingly decreased, while the crystal orientation is very slightly decreased with filler contents. So we conclude that the smaller Young's modulus of drawn composite is related to the smaller degrees of orientation of amorphous region. And it supports that decrease of the amorphous orientation is partly due to the bound polymer which is formed around the filler surface and partly due to the hindrance effect of filler particles on the molecular orientation.View full abstractDownload PDF (1608K) -
Kuniyoshi ITOYAMA, Atsuhiko SODA1976 Volume 33 Issue 8 Pages 471-478
Published: August 25, 1976
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSAn experimental study on steady flow, Barus effect, and melt fracture of ABS polymers having various rubber concentrations has been carried out by using a capillary rheometer. The increase of melt viscosity with increasing rubber concentrations is attributed to strong interaction between rubber particles and its surronudings even at relatively high shear rate such as at 102-103sec-1. It has been shown that superposition laws of temperature-time and of concentration-time hold for the flow curve of ABS polymers. A shift factor in temperature-time superposition is found to conform to the Arrhenius type equation and a shift factor in concentration-time superposition to the Mooney type equation. When the rubber concentration becomes high, concentration-time superposition does not hold in the region of lower shear rate. Die swell ratio decreases monotonously with increasing the rubber concentration. A master curve is obtained for the reduced variables of die swell ratio and shear rate with the method described by Petraglia et al. In dispersed two-phase systems, the critical shear stresses at the onset of melt fracture, τwc, are expressed in the following equation:
τwc (Xw) =τwc (0) (1+1.56×10-2Xw)
where τwc (Xw) and τwc (0) are the critical shear stresses at rubber concentration Xw and 0, respectively.View full abstractDownload PDF (2029K) -
Katsuyuki OGURA, Keigo OZAWA, Yoshio IWAKURA, Shigeo NAKAMURA1976 Volume 33 Issue 8 Pages 479-481
Published: August 25, 1976
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSFrom the temperature dependences of the amide bands (I, II, and V) in the infrared spectrum of poly (β-benzyl-L-aspartate), it was proposed that a transition of random coil-β form coexists with the usual α-ω transition. The decrease in peak absorbance at 1636 cm-1 which is characteristic of the β form and the appearance of a new band at 630 cm-1 at the usual transition temperature suggested the thermal decomposition of the β form competes with the transition.View full abstractDownload PDF (553K) -
Makoto TAKEISHI, Hiraku HAYASAKA, Shogo NIINO, Shigeru HAYAMA1976 Volume 33 Issue 8 Pages 483-486
Published: August 25, 1976
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSCl atoms of poly (vinyl chloride) were substituted by azido groups and the obtained polymer was treated with triphenylphosphine to form the polymer containing iminophosphorane structure. From this polymer a polyphosphonium salt was synthesized by an intramolecular substitution. The structure of the polycation was invesigated.View full abstractDownload PDF (724K)
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