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Volume 44, Issue 8
Displaying 1-7 of 7 articles from this issue
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Kunio Nakamura, Hyoe Hatakeyama1990 Volume 44 Issue 8 Pages 849-855
Published: August 01, 1990
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSNew types of polyurethanes were synthesized from kraft lignin, solvolysis lignin and wood meal by polymerization with polyethylene glycol (PEG) and diphenylmethane diisocyanate (MDI). The results obtained are as follows.
(1) Polyurethane films were made by solvent casting, and their tensile properties were measured. It was found that kraft and solvolysis lignins contributed effectively to an improvement in the mechanical properties of polyurethanes. Polyurethanes of considerable toughness were obtained, under specific conditions of the isocyanate/hydroxyl group ratio (NCO/OH) and also depending on either kraft or solvolysis lignin content. At high kraft and solvolysis contents, the obtained polyurethanes were hard and brittle, regardless of the NCO/OH ratio used in the experiment.
(2) Polyurethane foams were synthesized from a three-component system consisting of PEG, MDI and kraft lignin. Polyurethane foams having kraft lignin contents of up to 40% and apparent densities ranging from 0.04 to 0.22 g/cm3 were prepared by controlling the kraft lignin content, NCO/OH ratio and water content. The compressive strength and elasticity of the polyurethane foams increased with increasing kraft lignin content and NCO/OH ratio.
(3) Polyurethane films and foams, which were synthesized by using wood meal as a raw material, generally showed similar mechanical properties to those of polyurethanes which were synthesized from kraft and solvolysis lignins.View full abstractDownload PDF (1113K) -
Makoto Iwasaki1990 Volume 44 Issue 8 Pages 856-864
Published: August 01, 1990
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSDownload PDF (1154K) -
Yasuo Okita, Tsugio Matsubara1990 Volume 44 Issue 8 Pages 865-874
Published: August 01, 1990
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSAn organic filler, which is obtained by urea-formaldehyde condensation, has been used to light weight paper in recent years.
It improves brightness and opacity, in addition it has a very high absorptional ability of liquid owing to its porous structure.
A number of industrial benefits, which have not been achieved by common inorganic fillers, are obtained by its use.
These characteristics and paper making uses of its organic filler are discussed in this paper.View full abstractDownload PDF (3572K) -
Rapid Progress in High Product QualityTakeshi Kanazawa1990 Volume 44 Issue 8 Pages 875-890
Published: August 01, 1990
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSAikawa has had rich experiences for deinking technology from toilet paper, tissue paper to news papers, printing paper and respond to various deinking requirements. The biggest subject in a deink plant is how to treat difficult deink printed paper and solve sticky problems. The removal of the contaminants by excellent screening facilities without cutting of impurities, …… Aikawa's deink systems are made by various combinations of superior technologies of Helipoire, coarse and fine screening, and light weight impurity cleaner. Difficult deink printed paper, with high brightness and quality deinked pulp can be produced by the combination of superior defibering and ink dispersing accomplished by the Helipoire, Dispersion and deinking by the DA-Verticel.View full abstractDownload PDF (15146K) -
Part 4 Board Machine, Off Coater and EnvironmentEnergy Committee1990 Volume 44 Issue 8 Pages 891-909
Published: August 01, 1990
Released on J-STAGE: November 19, 2009
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Hiroo Tanaka, Kazuhide Yamakawa1990 Volume 44 Issue 8 Pages 911-917
Published: August 01, 1990
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSCationic polyacrylamide (C-PAM) with the charge density of 2.1 meq/g and the degree of polymerization of 5650 was prepared by the modified Hofmann reaction of PAM. C-PAM was slightly dansylated (fluorescently labeled) in a homogeneous system using aqueous dimethylformamide as solvent. The fluorescent labeling had no effect on the adsorptibity of C-PAM on cellulose fibers.
The adsorption of C-PAM or dansylated C-PAM (DC-PAM) reached the saturation level after only a few days when the concentration of electrolyte was high whereas that continued even after 10 days when the concentration of electrolyte was low. The pre-adsorbed DC-PAM on fibers was exchanged by C-PAM. The exchange reactions proceeded quite rapidly when the contact time between fibers and DC-PAM was short. The exchange became more difficult with increasing contact time. In conclusion, the presented results show that cationic polymer can gradually walk into the pores of fibers by vermiculation.View full abstractDownload PDF (866K) -
1990 Volume 44 Issue 8 Pages 918-926
Published: August 01, 1990
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSDownload PDF (1478K)
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