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Volume 70, Issue 10
Displaying 1-15 of 15 articles from this issue
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Comprehensive Papers
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Azusa SAIKA, Takeharu TSUGE2013 Volume 70 Issue 10 Pages 513-519
Published: October 25, 2013
Released on J-STAGE: October 25, 2013
JOURNAL FREE ACCESSPolyhydroxyalkanoates (PHAs) are bio-based and biodegradable polyester synthesized by a wide variety of bacteria. To enhance the usability of PHA, we need to improve the material performance for wide-ranging applications and reduce the production cost during fermentation. We have developed biosynthesis methods for a novel PHA copolymer consisting of 3-hydroxybutyrate (3HB) and 3-hydroxy-4-methylvalerate (3H4MV) [P(3HB-co-3H4MV)], which shows improved long-term stability and processability than other known PHA copolymers. P(3HB-co-3H4MV) has the potential to broaden the use of PHA if it can be produced from inexpensive sugars with controlled 3H4MV fraction. This article summarizes recent advances in the study of P(3HB-co-3H4MV) biosynthesis.View full abstractDownload PDF (646K) -
Kazuya YAMAMOTO, Jun-ichi KADOKAWA2013 Volume 70 Issue 10 Pages 520-528
Published: October 25, 2013
Released on J-STAGE: October 25, 2013
JOURNAL FREE ACCESSTo produce new polysaccharide-based materials, we have noted ionic liquids, which are low-melting point salts and liquid at temperatures below the boiling point of water. Because ionic liquids have been recently found to be used as solvents for natural polysaccharides such as cellulose, and accordingly, can be considered to have a specific affinity for polysaccharides, efficient methods to produce new polysaccharide-based materials are developed using ionic liquids to lead to the practical use of natural polysaccharides as the promising biomass resources.
As our recent topics are related to the above research area, in this paper, the preparation of chitin- and galactomannan-based functional materials and self-assembled chitin nanofibers using ionic liquids was reviewed.View full abstractDownload PDF (1041K) -
Yukiko ENOMOTO-ROGERS, Hiroshi KAMITAKAHARA, Toshiyuki TAKANO, Noreen ...2013 Volume 70 Issue 10 Pages 529-538
Published: October 25, 2013
Released on J-STAGE: October 25, 2013
JOURNAL FREE ACCESSSynthesis and characterization of cellulose, xylan and glucomannan derivatives and their properties are studied for applications. Various end-functionalized cellulose derivatives were prepared by introduction of functional groups at the reducing-end. Preparation and characterization of cellulose diblock copolymers, graft copolymers with cellulose side-chains, cellulose-self-assembled gold nanoparticles and amphiphilic cellulose derivatives are described, and their self-assembled nanostructures were investigated. Xylan and glucomannan ester derivatives or graft copolymers were synthesized with the goal of using hemicellulose as a plastic material. Xylan and glucomannan esters formed transparent films and their mechanical properties were dependent on the alkyl chain length and degree of substitution. The xylan esters were found to work as excellent nuclei for poly(lactic acid).View full abstractDownload PDF (1375K)
Original Papers
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Shigeru YAO, Hiroshi SEKIGUTI, Shota ISHIDO, Chihiro TANOUE, Taishi HA ...2013 Volume 70 Issue 10 Pages 539-543
Published: October 25, 2013
Released on J-STAGE: October 25, 2013
JOURNAL FREE ACCESSCellulose is the most abundant biomass polymer in nature. Recently, cellulose nanofibers and composite- and functional-materials thereof are increasingly investigated. Additionally, the investigation about basics and applications of cellulose/ionic liquid solutions are also actively carried out. However, only membranes with a smooth surface structure similar to cellophane were obtained. We have dissolved cellulose in a mixed solution consisting of ionic liquid and organic solvent. We have evaluated the relationship between dissolution time and solution viscosity. By using a multiple solvent displacement method, we constructed a method to make heterogeneous membranes that were formed by spinodal decomposition. The membrane had a high specific surface area and thus, may be applied to high performance permeation membranes and separation membranes.View full abstractDownload PDF (960K) -
Satoshi HONDA, Akihito NAKAZAWA, Hiroshi SUGIMOTO2013 Volume 70 Issue 10 Pages 544-549
Published: October 25, 2013
Released on J-STAGE: October 25, 2013
JOURNAL FREE ACCESSIn this study, we report on the alternating copolymerization of carbon dioxide and cyclohexene oxide by a newly designed nickel thiaporphyrin complex [(STTP)NiCl; 1] catalyst. The copolymerization of cyclohexene oxide in the presence of 1 in THF at 40°C under 50 atm of CO2 selectively produced poly(cyclohexene carbonate) (PCHC). The dependence of this polymerization system on solvent, temperature, and CO2 pressure was examined. Furthermore, a series of Lewis bases or quaternary salts were added as a cocatalyst, revealing that the alternating manner of PCHC was definitively improved by using triphenylphosphine (Ph3P). The dependence of the polymerization system on the [1]/[Ph3P] ratio was further examined.View full abstractDownload PDF (576K) -
Eiichi AKIYAMA, Motofumi TEDUKA, Seiji MAEHAMA, Takao KAMOHARA2013 Volume 70 Issue 10 Pages 550-558
Published: October 25, 2013
Released on J-STAGE: October 25, 2013
JOURNAL FREE ACCESSPreparation of polyurethane via polycondensation was investigated in order to reduce the environmental load during the manufacturing process and under the restriction of selectable raw materials. On the base of the results of model reactions, polycondensation of ethyl ω-hydroxyalkylcarbamates as AB-type monomers and poly(tetramethylene glycol) and the following chain-extension using 1,6-hexamethylenediisocyanate was used to obtain polyurethanes. A similar compound (the same ratio of soft-/hard- segments) of a polyurethane via polyaddition was also prepared to compare the polyurethanes via polycondensation with the polyurethane via polyaddition. It was suggested that the carbon number in the hard segment of the polyurethane affected the thermal mechanical properties. The polyurethane via polycondensation with the even carbon number showed properties like a hard elastomer similar to the polyurethane via polyaddition. On the other hand, the polyurethane via polycondensation with the odd carbon number showed properties like a flexible and robust elastomer.View full abstractDownload PDF (1160K) -
Yuushou NAKAYAMA, Keisuke SAKAGUCHI, Ryo TANAKA, Zhengguo CAI, Takeshi ...2013 Volume 70 Issue 10 Pages 559-564
Published: October 25, 2013
Released on J-STAGE: October 25, 2013
JOURNAL FREE ACCESSDirect polycondensation of renewable monomers, itaconic acid and isosorbide, was examined by using various catalysts and radical scavengers. Among the tested compounds, a combination of HfCl4·2THF as a catalyst and galvinoxyl free radical as a radical scavenger was found to yield soluble polymers with relatively high molecular weights without significant isomerization of itaconic acid. The resulting polymers were amorphous, showing a Tg of ~84°C depending on their molecular weights. Treatment of the polymers with benzoyl peroxide gave an insoluble crosslinked polymer. Thus, the polycondensation of itaconic acid and isosorbide could produce sustainable and functional polymers.View full abstractDownload PDF (532K) -
Saeko MURAKAMI, Nobuyoshi AOKI2013 Volume 70 Issue 10 Pages 565-571
Published: October 25, 2013
Released on J-STAGE: October 25, 2013
JOURNAL FREE ACCESSOligo[(hexanediol-L-malate)-co-(hexanediol-succinate)] [oligo(HM-co-HS)] was prepared by the lipase-catalyzed polymerization of dimethyl L-malate, dimethyl succinate and 1,6-hexanediol in an environmentally benign bioprocess. These monomers can be derived from biomass resources. The contents of free hydroxyl groups in the oligomers was varied by changing the feed ratio of L-malate and succinate. Polyurethanes containing malic acid were synthesized by the reaction of enzymatically prepared oligo(HM-co-HS) and hexamethylene diisocyanate. The thermal properties of polyurethanes with different contents of L-malate and succinate were evaluated. Melting was observed for polyurethanes containing the oligomers with less than 20% L-malate. The glass transition temperatures of the polyurethanes increased with increasing contents of L-malate having a free hydroxyl group. The malate-containing polyurethanes were enzymatically degraded by lipase and the degradation products exclusively contained cyclic oligomers which may be repolymerized.View full abstractDownload PDF (571K) -
Hirohito YAMASAKI, Yasuyuki NAGASAWA, Narumi UCHIDA, Kimitoshi FUKUNAG ...2013 Volume 70 Issue 10 Pages 572-580
Published: October 25, 2013
Released on J-STAGE: October 25, 2013
JOURNAL FREE ACCESSIn recent years, the development of reformative technology to remove aromatic pollutants from industrial wastewater is attempted. We have carried out effective removal of phenol from wastewater by immobilizing phenol degradation bacteria onto hydrogels which are able to concentrate phenol. The spherical hydrogels were obtained by a photo-crosslinking reaction after gelation with calcium alginate. ENTG-mix-βCyD/HDI hydrogels were crosslinked polyethylene glycol units (ENTG) in the presence of βCyD/HDI powdery polymer obtained by crosslinking of βCyD with hexamethylene diisocyanate (HDI). Phenol degradation bacteria were immobilized onto the hydrogel and cultured for one month in a bubbling vessel. The changes of phenol concentration in model wastewater were determined by gas chromatography. The hydrogels were used for batchwise removal tests for 4 times at the initial phenol concentration of 500 mg/L. From the results of the average time for phenol degradation, activities of immobilized biocatalyst having βCyD component were greater than that of hydrogel without βCyD component. After use for 10 months, the effective performance was kept without decline.View full abstractDownload PDF (1146K) -
Takayuki TSUKEGI, Hiroki YANAGIDA, Keisaku YAMASHIRO, Yoshihito SHIRAI ...2013 Volume 70 Issue 10 Pages 581-588
Published: October 25, 2013
Released on J-STAGE: October 25, 2013
JOURNAL FREE ACCESSThe thermal degradation behavior of poly-L-lactic acid (PLLA)/acrylonitrile-styrene-butadiene (ABS) blends was investigated by thermal gravimetric (TG) analysis and pyrolysis-gas chromatography-mass spectroscopy. TG data were analyzed kinetically using simulation methods to estimate the kinetic parameters and degradation mechanisms. When magnesium oxide (MgO) was used as a catalyst, unzipping depolymerization proceeded to generate cyclic monomer L,L-lactide selectively in 99.0% yield. Based on the simulated kinetic analysis, it was estimated that the degradation behavior is a zero-order weight loss process and the depolymerization mechanism is a back-biting reaction from hydroxyl chain ends. Demonstration tests of PLLA/ABS/MgO blends were carried out with a twin-screw extruder, resulting in quantitative recovery of L,L-lactide with a high optical purity from PLLA ingredient and confirmation of material recyclability of ABS ingredient.View full abstractDownload PDF (1032K) -
Haruo NISHIDA, Takashi AWAKIHARA, Takayuki TSUKEGI, Yoshihito SHIRAI2013 Volume 70 Issue 10 Pages 589-595
Published: October 25, 2013
Released on J-STAGE: October 25, 2013
JOURNAL FREE ACCESSThermal degradation behavior of poly-L-lactic acid (PLLA)/bisphenol-A type polycarbonate (PC) blends was investigated to recover cyclic monomer: L,L-lactide selectively. Effects of catalysts and heating conditions on the degradation were analyzed by thermogravimetry and pyrolysis-gas chromatography/mass spectrometry, followed by detailed kinetic simulation. It was suggested that PLLA and PC ingredients interact with each other during the degradation process, inducing racemization and random degradation. When tin(II) oxide (SnO) 1 wt % was used as a catalyst, the thermogravimetric curve of PLLA/PC blend approximated a two-step weight loss profile and an ideal selective recovery of L,L-lactide was achieved at temperatures below 310°C. Therefore, it was confirmed that PLLA/PC blend is a selectively chemically recyclable material.View full abstractDownload PDF (964K) -
Haruo NISHIDA, Hiroki YANAGIDA, Masaki OMURA, Takayuki TSUKEGI, Nobuhi ...2013 Volume 70 Issue 10 Pages 596-601
Published: October 25, 2013
Released on J-STAGE: October 25, 2013
JOURNAL FREE ACCESSThe depolymerization of poly(L-lactic acid) (PLLA) by aluminum compounds was investigated to confirm the actual active species on the unzipping depolymerization of flame-resisting PLLA/Al(OH)3 composites. Aluminum lactate and aluminum triisopropoxide (ATIP) as expected active species were used as depolymerization catalysts and their catalytic behavior was analyzed kinetically by thermogravimetry and pyrolysis-gas chromatography/mass spectrometry. When ATIP was added, excellent depolymerization occurred, resulting in selective L,L-lactide recovery. We conclude that aluminum alkoxides are the actual species for the selective depolymerization behavior of PLLA/Al(OH)3 composites, which proceeds according to an unzipping depolymerization mechanism from Al-alkoxdes at chain ends.View full abstractDownload PDF (825K) -
Junko MIZUGUCHI, Tamotsu HASHIMOTO, Michio URUSHISAKI, Toshikazu SAKAG ...2013 Volume 70 Issue 10 Pages 602-608
Published: October 25, 2013
Released on J-STAGE: October 25, 2013
JOURNAL FREE ACCESSThe reaction of methacrylic acid with vinyl ethers of an epoxy group, 4-vinyloxybutyl glycidyl ether (VBGE) and cyclohexane dimethanol vinyl glycidyl ether (CHDMVG), provided two types of triple functional monomers with a polymerizable vinyl group, a curable epoxy group, and an acid-sensitive degradable hemiacetal ester linkage (GBEM and GMCHMEM, respectively). GBEM and GMCHMEM were polymerized with 2,2′-azobisisobutyronitrile (AIBN) to give relatively high-molecular-weight soluble polymers. Poly(GBEM) and poly(GMCHMEM) were then cured through their pendant epoxy functions with amine curing agents at 100°C for 2 h to produce the insoluble crosslinked poly(GBEM) and poly(GMCHMEM) thermosets. These cured epoxy resins were glassy and tough polymers and underwent degradation to give poly(methacrylic acid) via acid-catalyzed hydrolysis of the hemiacetal ester linkages in the polymers at room temperature.View full abstractDownload PDF (837K)
Notes
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Kosuke TOMITA, Norihito HAYASHI, Noritoshi IKEDA, Yumi KIKUCHI, Toshia ...2013 Volume 70 Issue 10 Pages 609-611
Published: October 25, 2013
Released on J-STAGE: October 25, 2013
JOURNAL FREE ACCESSThe authors have successfully isolated for the first time bacterial strains degrading nylon 12 (N12), nylon 6 (N6) and nylon 66 (N66). Yeast extract was added as a growth factor to the culture medium for N12 degradation. Its concentration of 0.1% was the optimum for the cultivation of the strain as well as the degradation of N12. This quantity is much larger than the usually added amount for the microbial degradation of plastics. That is to say, if we would have followed a usual protocol with an ordinary quantity of yeast extract, the degrading strain would not have been found. Our results also suggest that a 0.1% yeast extract is adequate for the degradation of N6 and N66.View full abstractDownload PDF (441K) -
Masahiro YOSHIZAWA-FUJITA, Yu KAKEGAWARA, Yuko TAKEOKA, Masahiro RIKUK ...2013 Volume 70 Issue 10 Pages 612-615
Published: October 25, 2013
Released on J-STAGE: October 25, 2013
JOURNAL FREE ACCESSPoly(L-lactic acid) was synthesized in ionic liquids by lipase-catalyzed ring-opening polymerizations. A lower molecular weight poly(L-lactic acid) (PLLA) and a higher molecular weight PLLA were obtained in the same batch. When up to 5 wt. % water was added, the ratio of the higher molecular weight PLLA increased with increasing water content. Also, the specific rotation of PLLAs increased, indicating that PLLAs with a high optical purity were obtained by the lipase-catalyzed polymerization of L-lactide in hydrated ILs.View full abstractDownload PDF (369K)
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