All issues
Predecessor
Volume 44, Issue 1
Displaying 1-10 of 10 articles from this issue
- |<
- <
- 1
- >
- >|
-
Yukio MIYAZAKI, Kenji KAMIDE1987 Volume 44 Issue 1 Pages 1-7
Published: January 25, 1987
Released on J-STAGE: March 25, 2010
JOURNAL FREE ACCESSThe effect of branching structure on dilute solution properties of a segment polyurethane was investigated. The segment polyurethane polymerized with methylene bis (4-phynyl isocyanate), polycaprolactone, and 2-aminoethanol was fractionated by successive precipitation fractionation using dimethylacetamide (DMAc) as the good solvent and a mixture of ethylether and n-heptane as the non-solvent. Limiting viscosity numbers [η], apparent weight-average molecular weights Mw, a apparent z-average radii of gyration <S2> 1/2g, a, and apparent second virial coefficients A2, a for segment polyurethane fractions in DMAc were determined by light scattering. For fractions having latger Mw, a, higher intramolecular branching densities were obtained from data for the polymer untreated and heated in DMAc containing 0.1vol% n-buthylamine at 50°C for 2h. This molecular weight dependence of branching density was reflected in upward curvatures found in log-log plots of [η] -Mw, a, <S2> 1/2z, <a-Mw, a and A2, a-Mw, a.View full abstractDownload PDF (1250K) -
Yasunori TARU, Kyo TAKAOKA1987 Volume 44 Issue 1 Pages 9-14
Published: January 25, 1987
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe concentration of the specific component at the surface of the amino-alkyd resin film that had formed from the amino resin and the alkyd resin was investigated by using ESCA. The results are as follows. The concentration of amino resin at the surface of this film was higher than that for the inner part. The quantities of this concentrated amino resin are largest at the surface of the film formed with 50 : 50 blend. The ratio of the amino resin fraction at the surface to that for the inner part was dependent on the blend fraction. This ratio is about 300 percent for the film in which the blended amino fraction was 5-10 percent.View full abstractDownload PDF (873K) -
Nobuaki KUWABARA, Noriko OBATA, Tomoko SUE1987 Volume 44 Issue 1 Pages 15-22
Published: January 25, 1987
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSEthylene-Vinyl alcohol copolymers (EVA) were acetalized with formaldehyde (F-EVA), acetaldehyde (A-EVA) and n-butylaldehyde (B-EVA) in a solid state. The effects of acetalization on the sorption, the permeation and the diffusion of water vapor for EVA films were investigated. The results obtained are as follows. (1) The sorption isotherms of water vapor for all the acetalized EVA films could be described by sigmoid curves. The amount of the water sorbed in a mono layer, which is estimated from the BET equation, increased in the order of A-EVA, F-EVA and B-EVA. (2) Folry-Huggins' interaction paramete χ1 for A-EVA was lowest among those for acetalized EVA studied here. (3) Permeability coefficienst (P) increased with increasing the degree of acetalization, which is due to an increase in diffusion coefficient (D). (4) In the range of low relative humidity, D increased with relative humidity, which is associated with the breaking of the hydrogen bonding in the polymer. However, D approached to a constant value as the relative humidity became higher. This is due to the clustering of water molecules. (5) At the relative humidity when D attained a constant value, the logarithm of D was linearly related to the degree of acetalization.View full abstractDownload PDF (1171K) -
Effect of Temperature on Characterization of Pull-out Tests for Nylon 6 Fiber-Epoxy Resin CompositesMinoru MIWA, Tadashi OHSAWA, Sachiyo SAMORI, Tomoko MIZUNO1987 Volume 44 Issue 1 Pages 23-27
Published: January 25, 1987
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThis paper presents the effects of temperature on the results of the single fiber pull-out test for Nylon 6 in epoxy resin. The maxiumum tensile stress versus embedment length curves for the pull-out tests consist of two regions. Temperature dependence of interfacial yield shear stress obtained from the first slope for the region of shorter embedment length can be explained mainly by the temperature dependence of thermal stress produced by the difference in thermal expansion coefficient between fiber and resin. The interfacial frictional force obtained from the second slope for the longer region is smaller at double figures than the above interfacial yield shear stress and agrees approximately with the frictional force estimated from the debonding process. This interfacial frictional force plays an important role in determining the fracture energy of the composite system.View full abstractDownload PDF (1268K) -
Maki ISHIZAWA, Hiroshi OHSHIMA1987 Volume 44 Issue 1 Pages 29-33
Published: January 25, 1987
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSHigh impact properties, such as shotgun shooting, of various thermoplastic resins were investigated. The following results were obtained. A high speed piercing test which yields the same fracture pattern as that for shotgun shooting can estimate the results of shotgun shooting impact. The fracture energy of high speed piercing can be expressed with a simple experimental equation in terms of velocity (piercing velocity: 0.1-10m/s) on various thermoplastic resins. The equation can estimate the fracture energy of a pellet (pellet velocity -300 m/s). The fracture behavior of high speed piercing can be explained qualitatively by use of a Voigt model of visco-elasticity. The thermoplastic styrene elastmer or urethane elastmer has the highest value of fracture energy.View full abstractDownload PDF (769K) -
Yasuo KATO, Seiji ENDO, Kunio KIMURA, Yuhiko YAMASHITA, Hiroshi TSUGIT ...1987 Volume 44 Issue 1 Pages 35-39
Published: January 25, 1987
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSPolycondensation of poly (p-oxybenzoyl) in solution was studied to establish the relation between the morphology of crystals and the reaction conditions. Poly (p-oxybenzoyl) whiskers can be formed by using liquid paraffin or Therm S 800 as a solvent. The observed density (1.50-1.51g/cm3) of obtained whiskers is close to density (1.52g/cm3) calculated from the X-ray data. The whiskers gave sharp peaks in the X-ray diffraction patterns, higher crystal-crystal transition temperatures in the differential scanning calorimetry and higher thermal decomposition temperatures in the thermal gravimetry. These facts suggest that the obtained needle crystals can be termed polymer whiskers.View full abstractDownload PDF (1162K) -
Yuhiko YAMASHITA, Yasuo KATO, Seiji ENDO, Kunio KIMURA, Hiroshi TSUGIT ...1987 Volume 44 Issue 1 Pages 41-44
Published: January 25, 1987
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe previously studied whiskers of poly (p-oxybenzoly) consist of the extended chain type crystals with high crystallinity. The formation mechaism of these whiskers ls discussed along their morphological features at the early stages of polymerization. The model has the following steps. 1) Oligomers of low DP polymerized in solution are precipitated in the form of lamella. 2) The lamellae pile up along the long axis of the needle crystals with a spiral growth caused by the screw dislocation. 3) After that, DP increases by the trans-esterification in the interlamellar regions and the reorganization of crystals occurs. A similar formation mechanism for other morphologies obtained with different coditions is also discussed.View full abstractDownload PDF (2062K) -
Minoru MIWA, Tadashi OHSAWA, Shinji IWATA1987 Volume 44 Issue 1 Pages 45-51
Published: January 25, 1987
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSHybrid composites were prepared by impregnating epoxy resin into a short fiber mat consisting of glass and Nylon fibers. The effects of the mix ratio of the reinforcing fibers (hybrid ratio) on both the tensile strength and the impact fracture energy of the hybrid composites were studied. As the hybrid ratio of Nylon fibers increases, the tensile strength decreases almost linearly. It is possible to estimate the tensile strength in each hybrid ratio by taking the yield shear stress at the fiber-matrix interface and the critical fiber length into consideration. As the hybrid ratio of Nylon fibers increases, the impact fracture energy increases almost linearly. The impact fracture energy of the composites changes with various hybrid ratios from an additive rule for hybrid mixtures. For example, when the hybrid ratio Nylon fibers is about 0.5, a hybrid composite has a high impact fracture energy 2.0-2.3 times higher than a composite reinforced with only glass fibers, but has only 70-80% tensile strength of the latter composite for the temperature range 30 to 90°C. However, such results were not obtained at 120°C.View full abstractDownload PDF (1278K) -
Hajimu KURUMATANI, Shoji NAGAOKA, Yuichi MORI, Hiroshi TANZAWA, Yoshik ...1987 Volume 44 Issue 1 Pages 53-57
Published: January 25, 1987
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe blood compatibility of polyacrylonitrile (PAN) membranes for plasma separation has been studied by using PAN copolymers with long poly (ethylene oxide) (PEO) chains. The copolymers were synthesized by the radical copolymerization of acrylonitrile and methoxy poly (ethylene glycol) monomethacrylate in dimethyl sulfoxide. The optimum conditions to prepare the membrane for plasma separation from the copolymers were determined. The in vitro evaluation using the blood of rabbit revealed that the adhesion of blood components onto the membranes decreased with increasing PEO content of the copolymers.View full abstractDownload PDF (1140K) -
Hiroshi INOUE, Taiji MIYAKE, Hidejiro TANAKA, Akira MATSUDA, Masaki KH ...1987 Volume 44 Issue 1 Pages 59-66
Published: January 25, 1987
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSEPDM that had been copolymerized by ethylene, propylene and dicyclopentadiene was selectively dissolved using various organic solvents. The components thus extracted were analyzed. This method achieved a component fractionation of EPDM according to its chemical composition, and also constituted an analytical procedure for determining the component distribution. To express the chemical composition distribution (CCD), the average ethylene content, standard deviation of CCD, and the asymmetry parameter of CCD curve were studied. In order to investigate the EPDMs that have high raw rubber tensile strength (RS), ethylene and propylene copolymer (EPM) was selected as a model for EPDM to study the relationship between temperature factor and CCD. The results of the molecular weight distribution (MWD) study of EPM by GPC showed that EPM is composed of three parts that have high ethylene content and have low ethylene content. These copolymers coexist with the main ethylene propylene random copolymer. Several different kinds of the active species were found to coexist in the catalyst system used. That the origin of the RS is due to the polyethylene crystals in EPDM was proved by X-ray analysis.View full abstractDownload PDF (1403K)
- |<
- <
- 1
- >
- >|