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Volume 25, Issue 10
Displaying 1-9 of 9 articles from this issue
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Yoshinosuke Nakajima1971 Volume 25 Issue 10 Pages 489-493
Published: 1971
Released on J-STAGE: January 22, 2010
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Koichi Ogiyama, Eiichi Taniguchi1971 Volume 25 Issue 10 Pages 494-498
Published: 1971
Released on J-STAGE: November 10, 2009
JOURNAL FREE ACCESSIt has been reported previously that the tropical wood-lignins, especially the hard wood-lignins showed much differences in comparison with the ordinary hard wood-lignins, that is the higher lignin content, the low methoxyl content and differences in UV- and IR-spectra as well as the low ratio of syringaldehyde to vanillin on alkaline nitrobenzene oxidation and thus, it was assumed that the structure of them would be similar to soft wood-lignins rather than hard wood-lignins.
In order to further clarify the characteristics of tropical wood-lignins, the exhaustively extracted wood meals such as red lauan, white lauan and agathis sap woods with ethanol-benzene mixture, 95%-ethanol, hot water and acetone-water mixture respectively and the dioxane-lignins prepared from them were suffered from alkaline-treatment or NaBH4-reduction and compared with each other and with the ordinary wood-lignins namely beech, walnut and red pine sap wood.
The same characteristics mentioned above were also supported in the investigations of extracted wood meals and dioxane-lignins.
However, it was newly found that the presence of alkali easily soluble fraction in tropical hard wood-lignins and their contents amounted to about 10% of the wood and about 30% based on the Klason-lignin-content of the extracted wood.
And also the residual lignins especially NaBH4-reduced dioxane-lignin showed essentially the same features as ordinary hard wood-lignins as shown in Table 15.
In tropical soft wood, much differences would not be found but it was deduced that the similar things would also be occured. Thus, it was concluded that every characteristics on tropical wood-lignins reported earlier were caused by the presence of alkali easily soluble lignin fraction.View full abstractDownload PDF (1005K) -
Paul Rerolle1971 Volume 25 Issue 10 Pages 499-505
Published: 1971
Released on J-STAGE: November 10, 2009
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On the Preparation of Vanillin by Air OxidationShoji Kagawa, Masayuki Rokugawa1971 Volume 25 Issue 10 Pages 506-511
Published: 1971
Released on J-STAGE: November 10, 2009
JOURNAL FREE ACCESSCondition necessary for oxidation of lignin by air have been studied. Variables considered : time of reaction, temperature, weight of air, isolation method of pure vanillin. Vanillin was identified as an important product of the reaction when carried out at high temperature.
Studies were made on the use of crude alkali lignin from black liquor of soda pulp waste liquor as raw material for the production of vanillin. The results indicated that air oxidation was as amenable to crude alkali lignin as alkali nitrobenzene oxidation. Optimum conditions yield of vanillin was about 6.90% of lignin (in vanillin 2, 4-dinitrophenyl-hydrazone, 7.53%).
Isolation method of pure vanillin depending upon condition by sublimation have been discovered, and yield of pure vanillin was 4.80% of lignin (purity 90.2%).View full abstractDownload PDF (1218K) -
DP Distribution of Irradiated PulpsTakeo Ueno, Masahiro Murakami, Koji Murakami, Rikizo Imamura1971 Volume 25 Issue 10 Pages 512-521
Published: 1971
Released on J-STAGE: November 10, 2009
JOURNAL FREE ACCESSIn order to clarify the actual circumstances of radiation-induced depolymerization of cellulose (dissolving pulps), DP distribution of cellulose trinitrates (CTN) obtained from low DP pulps by irradiation have been studied by using gel permeation chromatography (GPC).
(1) A GPC calibration curve (counts vs. DP) covering wide DP range has been able to be drawn up with the fractions of two cellulose nitrates prepared from high DP wood pulps and rayon staple fibers. Since all of the fractions are not monodisperse, this calibration curve is rather qualitative but indicates the mean values of corresponding DP against the wide count range.
(2) Low DP pulps irradiated uniformly show more uniform DP distribution than unirradiated original pulps. Moreover, DP distributions of CTN prepared from alkali cellulose (just before xanthation) and rayon staples which have been obtained from the “no-aging” viscose process of the uniformly irradiated pulps, are similar to those of corresponding CTN from the conventional process.
(3) In order to improve the uniformity of irradiation by electron beams, the use of electron filters for high voltage electron accelerator (1.7 MeV) and the application of back-scattering for low voltage electron accelerator (0.5 MeV) were studied previously, and in this investigation it has been confirmed, from DP distribution of low DP pulps obtained through above methods, that these methods are effective for the irradiation of pulps by electron beams.View full abstractDownload PDF (2182K) -
Investigations of Acrylamide Polymer for Mucilaginous MaterialPaper Manufacture Section1971 Volume 25 Issue 10 Pages 522-534
Published: 1971
Released on J-STAGE: November 10, 2009
JOURNAL FREE ACCESSSuspensions in cylinder machine essentially adapted for providing more uniform webs are formed by adding 0.10 to 1.88 weight percent of a water soluble acrylamide polymer having, molecular in excess of 3, 000, 000 and a percent hydrolysis not in excess of 30 percent to an aqueous suspension containing cellulose fiber.View full abstractDownload PDF (2743K) -
Asada Kagakukogyo Co.1971 Volume 25 Issue 10 Pages 535-539
Published: 1971
Released on J-STAGE: November 10, 2009
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1971 Volume 25 Issue 10 Pages Preface14
Published: 1971
Released on J-STAGE: November 10, 2009
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1971 Volume 25 Issue 10 Pages Preface15
Published: 1971
Released on J-STAGE: November 10, 2009
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