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Volume 37, Issue 2
Displaying 1-11 of 11 articles from this issue
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Yuhiko Yamashita, Kazuo Monobe1981 Volume 37 Issue 2 Pages T53-T58
Published: February 10, 1981
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSIn a previous paper we speculated that the molecular conformation of poly (ethylene terephthalate) (PET) quenched from the melt is not in random coil state but in frozen metastable state which is easily transformed into the stable crystalline state. This speculation should be confirmed with direct structural evidences. However, experimental methods to investigate the structure of melt-quenched PET are scarce. In this paper we have evaluated the trans fraction in CH2-CH2 bonds of PET quenched from the melt by means of infrared spectroscopy.
The trans fraction was determined by two methods. The first one uses the ratio of intensities of the annealed sample and the melt-quenched one for both the trans and gauche bands (At/A°t and Ag/A°g). The trans fraction of melt-quenched PET (X°t) can be obtained from the following equation; where Ft and Fg are the ratio of extinction coefficient of the annealed sample and that of the meltquenched one for trans and gauche chain respectively. These are assumed to be unity. Scbönherr used the peak heights as the absorbance values and the 1578 cm-1 band as the internal thickness band. However, our study shows that the band widths change upon annealing and the 1578 cm-1 band is a crystallization sensitive band. In order to obtain reasonable value of the trans fraction, we used the integrated intensities as the absorbance values and the 1505 cm-1 band as the internal thickness band. Namely, a computer program was written which resolves the infrared spectar in the 760-930 cm-1 region of PET into composite vibrational bands whose envelopes are assumed to be Lorenzian. The computation was based on the principle of least squares. The integrated absorption intensity for the individual band was accurately obtained. By these procedures, we evaluated 0.2 as the value of trans fraction in melt-quenched PET.
The second one is newly proposed here. If one obtains the ratio of extinction coefficient of the trans and the gauche band (εt /εg ), the trans fraction (X°t) can be evaluated from the following equation; where A°t and A°g are the absorbances for the trans and gauche band in melt-quenched PET. The ratio of extinction coefficient of the trans and the gauche band was determined by using intensities of the trans and the gauche band in crystals of diol type oligomers of PET in which the CH2-CH2 bonds in both molecular ends were found to be gauche. The result was consistent with that from the improved Schönherr's method. Thus, a considerably small value of 0.2 is conclusively assigned to the trans fraction in CH2-CH2 bonds of melt-quenched PET.View full abstractDownload PDF (471K) -
Yuhiko Yamashita, Kazuo Monobe1981 Volume 37 Issue 2 Pages T59-T64
Published: February 10, 1981
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSIn a preceding paper we determined the absolute trans fraction of CH2-CH2 bonds in melt-quenched poly (ethylene terephthalate) (PET) by means of infrared spectroscopy. The obtained fraction was an unexpectedly small value, 0.2, which is inconsistent with the probability of trans conformers, 0.3, averaged over all internal bonds of the unperturbed chain. From this fact and density consideration, we suggested that each chain in melt-quenched PET does not possess the random coil conformation but the folded chain conformation containing specially preferable conformers. In order to obtain the reasonable local conformation for the sequence CO-O-CH2-CH2-O-CO, we calculated the intramolecular potential energy. From this and a consideration of the intermolecular chain packing, the trans fraction of the ethylene glycol moiety and the fine structure of melt-quenched PET were discussed. In conclusion we suggest that the fine structure of meltquenched PET is very close to that in the crystals and is characterized as such that the crystallographic requirement between parallel folded chains is not satisfied owing to the irregular foldings.View full abstractDownload PDF (501K) -
Masataka Kurokawa, Nobuo Nohara, Takashi Konishi1981 Volume 37 Issue 2 Pages T65-T70
Published: February 10, 1981
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThe results of WAXS and SAXS on the surface layer of nylon monofilaments which were twisted repeatedly at high temperature are reported. The (002) reflections for nylon 6 or the (010) reflections for nylon 610 were gradually split into the double peak by increasing the number of S direction twist repetition. The direction of split reflections has been corresponded to kink band direction. The WAXS and SAXS patterns of the filaments twisted and untwisted repeatedly towards one direction corresponded to the single texture pattern. When the filaments were twisted towards the opposite direction after being twisted repeatedly towards one direction, the (002) or (010) reflections became broad arcs in the same positions. Simultaneously SAXS patterns changed to the two point patterns on the meridian and the long period value decreased by the continuous deformation.
The changes of these X-ray diffraction patterns may be related to the relaxation of the lamellar structure in the fibrils deformed to the single texture by the repeated twisting procedure. However, it is difficult to correlate these changes with the morphological changes in nylon filament described in our previous paper.View full abstractDownload PDF (1859K) -
YUTAKA HIRANO1981 Volume 37 Issue 2 Pages P71-P76
Published: February 10, 1981
Released on J-STAGE: November 28, 2008
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Akira Watanabe, Shinya Kurosaki, Fujio Konda, Hiroshi Kondoh1981 Volume 37 Issue 2 Pages T71-T76
Published: February 10, 1981
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSIn previous papers, the tensile strength and the deformation of fabric structure under extension were investigated on both the twistless and twisted yarn fabrics.
In this paper, the relationship between the tensile properties of the fabric and the yarn deformation in the fabric is discussed. The tensile load-elongation curves of the twistless yarn fabrics (Twl-R) and twisted ones (N-R) are plotted on log scale. It seems that these curves are composed of the initial curved line and straight line, except high extension. The elongation at the cross-point of the initial curved line and the straight line is termed Iε. From the microphotographs of the yarn cross-section in the fabric under extension, the yarn packing factor (1-ε) and the yarn crimp angle (θ) were measured.
The results are summarized as follows. In the region where the elongation is smaller than Iε, the removal of the yarn crimp in the fabric takes place mainly, and in the rest region, the elongation of yarn in the fabric takes place in the tensile direction. At the points of Iε in Twl-R and N-R fabrics, the yarn crimp angles (θ) and the yarn packing factor (1-ε) are almost the same value in all samples, independent of twist existence and the fabric density.View full abstractDownload PDF (814K) -
Toshinari Nakajima, Hiromi Gocho1981 Volume 37 Issue 2 Pages T77-T84
Published: February 10, 1981
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThe chromatographic behavior of n-dodecane, water, benzene and n-caproic and with polystyrene (PS), poly4-vinylpyridine (PVP), acrylic fiber (PAN) and cotton fiber was investigated at a wide range of temperature.
For systems of PS/water, PS/benzene, PVP/water, PAN/n-caproic acid and cotton/n-caproic acid, plots of retention volume against sample size were seen to pass through a minimun, respectively, At high probe concentration, the retention volume VR was linearly related with sample size s. At low probe concentration, 1/VR was related to s through 1/VR=A/(1+B√s), where A and B were constants. Limiting retention volume, VR°, was estimated for the high and low probe concentration ranges by extrapolating the proper relations to s=0. The values of heat of adsorption obtained for the two concentratio regions were compared. The showed that at low probe concentration, probes interacted strongly with polymers.
Adsorption isotherms were determined for n-dodecane and water on PS respectively, From the results, it is suggested that adsorption on the polymer surface is the main sorption mechanism below Tg and diffusion into the bulk of the polymer dominates above Tg.View full abstractDownload PDF (454K) -
YOSHIKAZU KOSAKA, HIROSHI IWASHIMA, MASATAKA INOMOTO, TAKAO TOZAKI1981 Volume 37 Issue 2 Pages P77-P85
Published: February 10, 1981
Released on J-STAGE: November 28, 2008
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Tomiji Wakida, Takeshi Kako1981 Volume 37 Issue 2 Pages T85-T88
Published: February 10, 1981
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSChange in the fine structure of Polyester fibers treated with Carriers such as Orthophenyl phenol (OPP) and Methyl salicylate was investigated in relation to the study of organic solvent/water treatment. Furthermore, Polyester fibers heat-set under fixed and relaxed conditions were treated also in the same way.
Crystallinity by density measurement, X-ray diffraction pattern, and crystallite size and lattice spacing of these fibers were investigated. The fibers treated with the Carriers, especially OPP showed a clear reflectance image of (010), (_??_10), (100) and (0_??_1) planes and increases in the crystallite size and the crystallinity.
On the other hand saturation values of C. I Disperse Violet 1 of these fibers also increased by the Carrier treatment. These results are the same as those obtained for the treatment of Polyester fiber with organic solvent/water such as benzyl alcohol/water reported previously.
Carrier treatment of Polyester fiber leads to a considerable change of the fine structure not only in the crystalline region, but also in the amorphous regionView full abstractDownload PDF (1348K) -
AKIRA TAKAOKA1981 Volume 37 Issue 2 Pages P86-P91
Published: February 10, 1981
Released on J-STAGE: November 28, 2008
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SHUNZO ISHIZAKI1981 Volume 37 Issue 2 Pages P92-P99
Published: February 10, 1981
Released on J-STAGE: November 28, 2008
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MASAO MATSUI, YOSHIKAZU KONDO, KENJI ARAI, TAKAJI YAMAMOTO1981 Volume 37 Issue 2 Pages P100-P113
Published: February 10, 1981
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSDownload PDF (3701K)
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