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Volume 25, Issue 11
Displaying 1-5 of 5 articles from this issue
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Toshisada Takahashi1969 Volume 25 Issue 11 Pages 473-479
Published: November 10, 1969
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSPrevious studies on regenerated cellulose have led us to a conclusion that the selective uniplanar orientation of (101) planes of cellulose II crystals occurs during the coagulation and regeneration process. The purpose of this work is to investigate the similar problem, that is the selective uniplanar orientation of polyvinylalcohol crystals caused during the coagulation. It was found that the degree of orientation depends on the concentration of sulfate and coagulation temperature. Higher degree of orientation of (101) planes were observed in the films prepard in the bath of lower temperature containing much salt. Degree of preferential orientation of (101) planes was evaluated in terms of a relative parameter; where I(101) and I(10_??_) were the X-ray scattering intencities of (101) and (10_??_) planes respectively, both measured by the reflection method, and i(101) and i(10_??_) were that obtained for isotropic specimen.
Polyvinylalcohol films, in which (101) planes orient parallel to thies surfaces, showed higher swelling and shrinkage in thickness than in surface area, indicating that water permeate between (101) surfaces of polyvinylalcohol crystals. This result may be explaind on the basis of the direction of hydrogen bonds formed between pairs of molecules. In addition to the above behavior of anisotropic swelling and shrinkage, the restrained crystal growth in the direction perpendicular to (101) planes gives another support to the hypothesis that (101) planes are hydrophilic and sensitive to water. From these consideretions, it may be concluded also for the orientation mechanism that absorbed water plasticizes the crystals so as to glide each other along their (101) surfaces, and consequently crystals rotate to bring their planes to parallel position of the film surface.
Gliding in crystals could also takes place in another situation, where swollen polyvinylalcohol consisting of imperfect crystals is compressed, since there intermolecular hydrogen bonds would be weakened by water. This mechanism is very similar to that of the preferential orientation of (101) planes in cellulose crystals proposed in our earlier papers.View full abstractDownload PDF (586K) -
Tamio Arakawa, Fumio Nagatoshi, Naoki Arai1969 Volume 25 Issue 11 Pages 480-487
Published: November 10, 1969
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSMelting behavior was studied on the undrawn filaments of nylon 6 heat treated at various temperatures (Tc) from 165 to 210°C. It was found that the true melting temperature (Tm) of lamellar crystals of nylon 6 can be obtained by properly methoxymethylating the samples prior to thermal analysis. With the progress of the reaction in the amorphous regions, the complex melting curve of an as annealed sample is gradually unified into a sharp melting peak, and the half value breadth of the peak becomes minimum at the optimum degree of methoxymethylation. The corresponding peak temperature can be identified as Tm. Tm thus obtained was found to be in a linear relation with Tc in a wide range of the latter. When methoxymethylated to a proper degree the melting of the crystalline lamellae can be considered to take place under equiliblium conditions. It has been found that lamellar crystals have uniform thickness even when they are formed at temperatures considerably below the equiliblium melting point.
The cross links in the amorphous regions surrounding the lamellar crystals can raise their melting temperature to large extent. The decrease in the entropy of fusion can explain the phenomenon.
The isothermal thickening of the lamellar crystals of nylon 6 was analysed using the dependence of Tm on their thickness (lc). It was found that the increase in 1c is in linear relation with the logarithm of the annealing time, while the long period remains constant. A mechanism for the thickening of crystalline lamellae was proposed which prohibits mass transfer along the chain axis in the crystalline region.View full abstractDownload PDF (1337K) -
Mitsuo Kimura, Tetsuo Takahashi, Toru Shimizu1969 Volume 25 Issue 11 Pages 488-493
Published: November 10, 1969
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThe present investigation concerns with an apllication of the automatic recording liquid chromatography with thermal detection to the adsorption measurement. The adsorption of hydrochloric acid on polyamide powder was measured isothermally at 30°C, 40°C and 50°C. Polyamide powder was packed in two columns with thermo couple and put into double thermostat. Firstly, distilled water was flowed in at the constant flow rate in order to stabilize the thermo couple, then hydrochloric acid was flowed. The heat of adsorption around the thermo couple was recorded as change in temperature and the total variation (peak areas=Hw) was observed. The pH-Hw isotherm was almost agreed to the adsorption isotherm of hydrochloric acid on polyamide and these isotherms were in good agreement with the Langmuir's adsorption isotherm between pH4.30 to pH2.50. From these pH-Hw isotherms, the standard abilities and standard heat of adsorption were obtained. These values [ex. -Δμ°=10.2kcal/mol (40°C), -ΔH=12.0kcal/mol] were essentially identical to values from adsorption isotherm and other reports. From a consideration of these results, it seems most reasonable to conclude that the automatic recording of liquid chromatography with thermal detection is useful to measurement of adsorption.View full abstractDownload PDF (363K) -
Noboru Aisaka, Tadashi Shindo, Tatsuya Kawakami1969 Volume 25 Issue 11 Pages 494-501
Published: November 10, 1969
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSIn order to verify the new pattern-producing methods for the circular rib-knitting, proposed previously by the authors1, 3), a prototype unit for the pattern-producing controller was deviced, and some experiments are performed on the apparatus with three-color pattern (a circular rib-knitting machine of 20-inch diameter, the gauge with 12 needles per inch, and 6 yarn feeders).
The results showed the high utility of the new pattern-producing methods, and it was confirmed that not only the enlargement of pattern area, simplification and rapidification of pattern change are promoted but also some new patterns can be knitted by this method.
Moreover, it is considered that by the utilization of the industrial digital computer as the general pattern controller, the multification of pattern varieties is promoted and lower cost for equipment can be expected by adopting the concentration control method for several knitting machinesView full abstractDownload PDF (3642K) -
Tatsuya Hongu1969 Volume 25 Issue 11 Pages 502-513
Published: November 10, 1969
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSW & W finishing of cotton fabrics with various bis-epoxy compounds in the presence of acidic catalysts by the conventional pad-dry-cure technique was investigated in detail. Epoxy compounds studied were diglycidyl ether (Epoxide I), ethylene glycol diglycidyl ether (Epoxide II), glycerin diglycidyl ether (Epoxide III), butanediol diglycidyl ether(Epoxide IV), diethylene glycol diglycidyl ether (Epoxide V), polyethylene glycol diglycidyl ether (Epoxide VI), and vinylcyclohexene dioxide (Epoxide VII). The effectiveness of the epoxy compounds and catalysts to improve dry and wet wrinkle recovery angles were in the order, Epoxide I> Epoxide III> Epoxide VI> Epoxide II> Epoxide IV> Epoxide VII, and in the order, Mg (BF4)2> Zn (BF4)2> Mg (ClO4)2> A12 (SO4)3, respectively. Highly effective Epoxide I, Epoxide II and Epoxide VI are all soluble in water, while others are hydrophobic. The tearing strength decreased with increasing the wrinkle recovery angle. When the impregnated fabric was cured at temperatures lower than 100°C, high wet wrinkle recovery angle with improved retention of the tearing strength was realized.
Epoxide-treatment with conventional resins was also investigated. When Epoxide III was used with dimethyloldihydroxyethleneurea (DMDHEU), the chlorine damage associated with DMDHEU was eliminated.View full abstractDownload PDF (851K)
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