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Predecessor
Volume 54, Issue 8
Displaying 1-7 of 7 articles from this issue
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Hiroshi EYA, Yukie OTUJI, Tatsuo NAGAI, Kohji HATTORI1997 Volume 54 Issue 8 Pages 463-470
Published: August 25, 1997
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSA petri dish burial test was carried out with poly (3-hydroxybutyrate-co-3-hydroxyvalerate) [P (3HB-co-3HV)] films at 25°C in 11 kinds of soils and one mature moist compost preparation. The rate of biodegradation of the films was strongly dependent on the soil textures. The fastest rate of soil was 100% weight loss of the film at 50 days, while the slowest rate of soil was 20% at 3 months. Relationships between this test, the field testing at the collecting places of 9 kinds of soils and other factors were investigated. The degrading films seemed able sometimes to remain in soils for one year or more depending on the properties of soils and the environment. Next, the garbage with 3% addition of P (3HB-co-3HV) bags was applied to the composting verification test plant. It was found that P (3HB-co-3HV) bags were able to compost with garbage. It was confirmed that shredded P (3HB-co-3HV) bags did not prevent garbage from aerobic fermenting and composting; thus the material was degraded and became invisible to the naked eye in approximately 10-20 days.View full abstractDownload PDF (1611K) -
Hiroshi KUSANAGI1997 Volume 54 Issue 8 Pages 471-476
Published: August 25, 1997
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSNormal vibrations were calculated by means of the ab initio molecular orbital calculation method for a non-polar condensed-substance model composed of four polyethylene (PE) oligomers and a water molecule. The calculation results gave the intermolecular interaction energy ΔE=-2.2 kcal/mol for the H2O-PE condensed-substance model. This value is about 1/7 of ΔE=-15.5 kcal/mol for a polar condensed-substance model: H2O-Poly (vinyl fluoride) (PVF) oligomer model. This difference may be attributed to the contribution of the hydrogen-bonding energy of the polar PVF system. Moreover, the calculated stretching frequencies ν (OH) of the H2O molecule of PE system have proved to be located between the calculated stretching frequencies ν (OH) of the free H2O and of the interacting H2O of PVF system.View full abstractDownload PDF (833K) -
Akira TERAMOTO, Michito KOHNO, Koji ABE1997 Volume 54 Issue 8 Pages 477-482
Published: August 25, 1997
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSA polyelectrolyte complex (PEC) formed by N-isopropylacrylamide (NIPAAM) with ionic site may be expected to depend not only on pH and salt concentration but also on temperature. A series of copolymers of NIPAAM with ionic monomers (sodium acrylate (AAc), sodium styrenesulfonate (SS), dimethylaminoethylacrylate (DMAEA), and 2-acryloyltrimethylammonium chloride (TMAEA)) were synthesized. Thermo-transition behavior of these copolymers and their PEC was investigated. Transition temperatures of AAc copolymers were elevated with increasing AAc content, but those of DMAEA copolymers were independent of DMAEA content at pH 7.0. Copolymers containing SS or TMAEA did not show transition behavior even at a low content of ionic group. PEC showed lower transition temperatures than copolymers and a homopolymer of NIPAAM. This was explained as due to a dehydration of ionic site on polymer chain caused by PEC formation. Transition temperature of PEC were dependent on NaCl concentration. At lower salt concentration, the transition temperature of PEC were elevated by an electrostatic shielding effect induced by counter ions. At high salt concentration, the transition temperature was reduced by salting-out of the polymer chain. It was concluded that the transition temperature of these thermo-responsive PEC was able to be regulated by pH and salt concentration.View full abstractDownload PDF (1203K) -
Sadao HAYASHI, Takuya YAMANAKA, Tsuyoshi HATTORI1997 Volume 54 Issue 8 Pages 483-490
Published: August 25, 1997
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSOptics between two micro convex lens arrays on a spherical surface (SMLA) with an aperture of 0.20 mm made of poly (methyl methacrylate) has been investigated. The convex side of the SMLA set was turned to an object, and the imaging on the SMLA was observed from the concave side. The inverted image of the object SMLA focused by the lens at the center appeared in the middle of the lens, but those by other lenses shifted to the upper and lower sides or the right and left sides within each lens, as the lenses went away from the middle to the four sides on the SMLA. When the eye SMLA was superposed on the object SMLA, an image was formed on the shining lenses in the eye SMLA. When the inverted image pitch in the object SMLA was larger than the lens pitch of the eye SMLA, the image appeared as an upright one, and when the relation between the two pitches reversed, the image appeared as an inverted one. The mechanism of the image formation was clarified by Moiré fringes between the pitch of inverted images in the object SMLA and the pitch of lenses in the eye SMLA. When the radius of curvature of the SMLA was small, the magnification of an image appeared in the eye SMLA was proportional to the radius, and was inversely proportional to the distance between an object and the object SMLA.View full abstractDownload PDF (6886K) -
Takahiko TERADA, Hiroshi ONISHI, Yoshikazu YAMAGATA1997 Volume 54 Issue 8 Pages 491-498
Published: August 25, 1997
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThe problem of plastic waste disposal is getting more serious. Especially thermosets are difficult to recycle because their cross-linked nature means also they show insolubility and inability to soften on heating. We are searching for the thermosets which can be easily degraded as scrap. This study was undertaken to investigate whether containing biodegradable polymers helped raise the degradability of thermosets. As a result of our study, it was found that unsaturated polyester resins (UP) containing polycaprolactone (PCL) showed degradability in the mixture of NaOH aq. and ethanol at room temperature. In this mixture, ester bonds solvolyzed in UP as well as in PCL. And we supposed that existance of PCL in crystalline phase contributed to the degradability of blends. In conclusion the results suggested that thermosets/biodegradable polymer blends showed great degradability as well as conventional characteristics.View full abstractDownload PDF (2638K) -
Hiroyuki SHIRAHAMA, Masanori SAKANE, Hajime YASUDA1997 Volume 54 Issue 8 Pages 499-511
Published: August 25, 1997
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSWe have prepared the polyesterethers from cyclic ethers [ethylene oxide (EO), oxetane (OX), tetrahydrofuran (THF)] and lactones [δ-valerolactone (VL) and ε-caprolactone (CL)] in one-pot synthesis. Then, we have investigated the effect of the ether unit on the enzymatic degradation of the polymers obtained by cholesterol esterase. The measurements of NMR and thermal properties for the copolymers revealed that the chain sequences of EO/lactone copolymers were block, while those of THF/lactone and OX/VL copolymers were random. The block copolymers of OX with CL were prepared in two-pot synthesis, because each homopolymer was formed in a one-pot method. The introduction of (hydrophilic) ether unit into aliphatic polyester (viz., polylactone) chains resulted in the increase in enzymatic degradation. Further, it was found that the (enzymatic) degradability of random copolymers was greater than that of block copolymers. This result was confirmed by examining the degradability of DXO copolymers [DXO; 1, 5-dioxepane-2-one; corresponding to the alternating unit of EO and β-propiolactone (PL)]. Namely, the enzymatic degradation of (more random) DXO/PL copolymers was greater than that of EO/PL (random) copolymers. However, DXO/PL random copolymers were inferior to the PL homopolymer in thermal properties, Hence, we have synthesized diblock and triblock copolymers of DXO with lactone (VL or CL), and studied the enzymatic degradation of these block copolymers. Triblock copolymers showed a good degradability without much decreasing in the thermal properties.View full abstractDownload PDF (1973K) -
Kazuyuki KUWANO, Masataka MURAMATSU, Satoru CHIGONO, Mitsuru NAGASAWA1997 Volume 54 Issue 8 Pages 512-518
Published: August 25, 1997
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSFor design of top-coat paints for automobiles, we propose the use of degradation feasibility factor (DFF) defined by the weight percent of molecules containing less than three functional monomers which can be calculated by the copolymerization theory of Stockmayer.View full abstractDownload PDF (1342K)
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