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Predecessor
Volume 44, Issue 5
Displaying 1-10 of 10 articles from this issue
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Takashi TORII, Katsuhiko SUMITA, Sadao HIBI, Eiji NAKANISHI, Matsuo MA ...1987 Volume 44 Issue 5 Pages 331-339
Published: May 25, 1987
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe mechanisms of plastic deformations were further investigated in connection with the re-orientated molecular chain axis in the off-angle re-stretching of the rolled high density polyethylene (RHPE). The slippy or kinky deformation caused by off-angle re-stretching was analyzed on the basis of the strain ellipsoid, molecular chain vectors and a local coordinate system. The deformation is caused by the slip of inter-and intra-lamella. The molecular chain axis can be easily re-orientated in the film by a pure shear stress which is much larger than the simple shear stress. The kink band formation markedly promotes the re-orientation of the molecular chain axis.View full abstractDownload PDF (1474K) -
Sadao HIBI, Toshiyasu KATSUNO, Akihiro YOKOYAMA, Eiji NAKANISHI, Matsu ...1987 Volume 44 Issue 5 Pages 341-359
Published: May 25, 1987
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSSome physical quantities, such as elastic constant (or compliance) and intensities of polarized fluorescent light and laser-Raman scattering light passed through anisotropic polymer films, are governed by the results of space-averaging weighting with the molecular distribution function w (cos θ, φ η) of the fourth rank tensor Tijkl defined by a coordinate transformation of a fourth rank tensor. Some of the expansion coefficients of Tijki disappear due to the nature of symmetry in the sample. As proposed by Morris, the nonzero expansion coefficients remain only for the samples with symmetry higher than or equal to that of an orthogonal system. In the general case, which is represented by triclinic system, there can be imaginary parts in the remaining coefficients; these are classified into seven groups. These coefficients induced from generalization are important for evaluating molecular orientation by means of fluorescent method and Raman method wits oblique incidence of polarized light.View full abstractDownload PDF (1768K) -
Takashi TORII, Sadao HIBI, Katsuhiko SUMITA, Eiji NAKANISHI, Matsuo MA ...1987 Volume 44 Issue 5 Pages 361-368
Published: May 25, 1987
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSWe analyzed the re-orientation angle of molecular chain axes in the plastic deformation and the angles of kink band in the off-angle re-stretching of rolled high density polyethylene (RHPE). We evaluated the kink band angles using the characteristic curves. As the strain yield points in polymers became much greater than those of the metals, the change of orientation angles must be corrected due to elasto-plastic deformation. The re-orientation mechanisms of the chain axis during the off-angle stretching may be divided into the slipping and kinky deformations. These were given by the slippage of the inter-lamella and by the chain slip in the intra-lamella, respectively. The orientation of the molecular chain axis in the chain slip was much greater than that of the inter-lamella slip.View full abstractDownload PDF (1432K) -
Kenichiro SUETSUGU, Tadashi SAKAIRI1987 Volume 44 Issue 5 Pages 369-373
Published: May 25, 1987
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe distribution of fiber lengths in injection moldings of fiber reinforced composite materials was almost normal. Under the conditions for normal distribution, i. e., 3ν (standard deviation) ≅ L (average length), the equation of tensile strength reported by Yamaki becomes linear with regard to the parameter φ whichestimates the adhesion between filler and polymer and aspect ratio. According to this equation, the φ values of PC/GF and PP/GF prepared under various adhesive conditions were obtained. By using Cox's tensile strength equation assuming complete adhesion, φ0 was obtained and φ/φ0 was then caluculated. The results probably make possible the estimation of the effects of surface modifiers on adhesive conditions and the degree of adhesion.View full abstractDownload PDF (972K) -
Kensuke SAKURAI, Kooji HAYAKAWA, Toshisada TAKAHASHI1987 Volume 44 Issue 5 Pages 375-382
Published: May 25, 1987
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSUltra-high molecular weight polyethylene (UHMWPE) was drawn at 150°C (above melting point) and immediately quenched at 0°C. Samples of film were annealed at various temperatures at constant length. The fine structures were studied by wide- and small-angle X-ray analyses. Crystallites with a-axis orientation predominated for the quenched film with a high draw ratio of 12, in which the so-called bi-component crystallization might occur: most crystals were folded chain type, with a small number of extended chain crystals. The crystallites become rotated by thermal stress at annealing temperatures above 80°C. The crystallites took the c-axis orientation by annealing above 130°C. No large change in the crystallite length D002 by annealing was observed. The voids berween fibrils for quenched film decrease with increasing of annealing temperature; in other words, fibrils pack more closely. The long period gradually increased with annealing temperature and increased drastically at the high temperatures, above 100°C. The chain entanglement could not prevent the long period from increasing at the high temperatures, though the crosslinking had shown a partial effect. The large increase in long period can be explained by the following; premelting of crystallites, an increase of amorphous layer thickness accompanied by a removal of entanglements of ultra-high molecular chains, and an epitaxial crystal growth in the direction normal to the lateral crystallite surface.View full abstractDownload PDF (2192K) -
Toshinari NAKAJIMA, Kaoru IIDA1987 Volume 44 Issue 5 Pages 383-388
Published: May 25, 1987
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSSorption behavior of poly (ethylene terephthalate) (PET) was studied over a wide temperature range by using the method of Gas Chromatography. PET was used as a stationary phase in the column; mobile phases (probes) were a series of carboxylic acids with carbon numbers of 2, 3, 4, and 5: acetic acid, propionic acid, butyric acid and valeric acid. Results of previous work, in which the probes were a series of linear alcohols, i. e., ethanol, n-propanol, n-butanol, n-pentanol and o-chlorophenol, were compared. In PET-carboxylic acid systems, Vg (specific retention volume) was calculated and the S (sample size) -Vg relation was plotted. Vg increased with decreasing S over the entire temperature range. The limiting specific retention volume, Vg· was estimated for both regions by extrapolating the respective relation to S=0. In PET-carbo-xylic acid systems, a slight inflection point was observed in the range of about 150°C to 170°C, at which crystallization starts. The sorption isotherms were determined from the peak profile. For carboxylic acid, the amount of the probe adsorbed decreased with temperature and with increasing chain length of the probe. The sorption behavior of three systems were analysed using the adsorption isotherms, B.E.T. plot, and Flory-Huggins χ parameters. These results suggest that PET-carboxylic acid systems are almost B.E.T. type (adsoption type).View full abstractDownload PDF (886K) -
Norio TSUBOKAWA, Isamu YAMAMOTO, Yasuo SONE1987 Volume 44 Issue 5 Pages 389-394
Published: May 25, 1987
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSPolyamideimide (PAI) samples containing various amounts of amide and imide bonds were prepared by the polycondensation of trimellitic anhydride and trimellitic acid with 4, 4′-diphenylmethane diisocyanate. To clarify the curing mechanism of PAI, the effects of beating on its chemical structure and physical properties were investigated. (1) The increase in the intrinsic viscosity of PAI after heating was enhanced with an increase in its amide bond content. (2) The solubility of PAI in solvent was found to decrease with an increase in heating time, regardless of its imide bond content. (3) The solubility of PAI after heating in air was poorer than that in vacuum. (4) The heating of PAI above 180°C resulted in a precipitous fall of the elongation to a break point. (5) The crystallization of PAI upon heating was not observed. The above results suggest that the curing of PAI by heating is due to the crosslinking reaction between functional groups or terminal groups in the main or branch chains. When PAI was heated in air, the oxidation of diphenylmethane structure in the main chain had some influence on the curing of PAI.View full abstractDownload PDF (1149K) -
Yoshihiro OHMIYA, Takeshi SHINOHARA, Nobuto KANAI, Hirotaro KAMBE1987 Volume 44 Issue 5 Pages 395-398
Published: May 25, 1987
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSFor the purpose of making a more flexible composite, an aromatic polyamideimide (PAI) film was reinforced by aromatic polyamide fiber (Du Pont, Kevlar 49) to form a bidirectionally), oriented cloth composite. The fatigue strength of this composite film was investigated by cyclic tensile stress, with respect to the direction of fiber orientation. In the cloth composite film, the fatigue behavior was anisotropic, as were the other mechanical properties. The characteristics of fatigue life at the composite film were related to the intermediate characteristics of fatigue life at both the cloth reinforcement and the PAI matrix. The fatigue strength of the composite film may be correlated with its static strength.View full abstractDownload PDF (1236K) -
Shingetsu YAMADA, Shizuo TOKITO, Tetsuo TSUTSUI, Shogo SAITO1987 Volume 44 Issue 5 Pages 399-403
Published: May 25, 1987
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSSolid state properties, especially electric properties, of poly (2, 5-dibutoxy phenylene) (PDBP), one of the derivatives of poly (p-phenylene) (PPP), have been studied. Tough and flexible PDBP films obtained by casting from a toluene solution were used. From the studies of dielectric relaxation and dynamic viscoelasticity, two types of molecular motion, twist motion of main chains and local motions of butoxy groups, were found. The processibility of PDBP was attributed to the presence of these molecular motions. The dark conductivity of PDBP film was very low, less than 10-19 S/cm at room temperature. However, large photoconduction was observed during the irradiation of visible light. Furthermore, the dark conductivity increased after photoirradiation. These results suggested that PDBP films intrinsically have an ability of electronic conduction. The electronic conduction was enhanced by doping of iodine; the conductivity of PDBP reached semiconductive region, 10-9S/cm. Therefore, it was concluded that the introduction of a butoxy group into phenylene rings has little effect on the electronic structure of PPP.View full abstractDownload PDF (945K) -
Kuniyoshi ITOYAMA1987 Volume 44 Issue 5 Pages 405-408
Published: May 25, 1987
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSAn isotactic-polypropylene oriented sheet with the predominant β-crystal form which was induced by the elongational flow of polymer melts was prepared. The effects on β-form formation of the temperature at which the sheet was melted and of the time spent at melting temperature before crystallization have been studied by using DSC of the melting behavior of the polymer isothermally crystallized from the melt. The results show that the active crystallization center of β-form has a higher thermal stability beyond the melting point and that the melt does not lose its structural “memory” during annealing for 10min at 180°C, but this is lost during annealing for 1 min at 230-240°C.View full abstractDownload PDF (675K)
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