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1.
Biodegradation of Polycaprolactone Powders Proposed as Reference Test Materials for International Standard of Biodegradation Evaluation Method 总被引:1,自引:0,他引:1
Masahiro Funabashi Fumi Ninomiya Masao Kunioka 《Journal of Polymers and the Environment》2007,15(1):7-17
Polycaprolactone (PCL) powders were prepared from PCL pellets using a rotation mechanical mixer. PCL powders were separated
by sieves with 60 and 120 meshes into four classes; 0–125 μm, 125–250 μm, 0–250 μm and 250–500 μm. Biodegradation tests of
PCL powders and cellulose powders in an aqueous solution at 25°C were performed using the coulometer according to ISO 14851.
Biodegradation tests of PCL powders and cellulose powders in controlled compost at 58°C were performed by the Mitsui Chemical
Analysis and Consulting Service, Inc. according to ISO 14855-1 and by using the Microbial Oxidative Degradation Analyzer (MODA)
instrument according to ISO/DIS 14855-2. PCL powders were faster biodegraded than cellulose powders. The reproducibility of
biodegradation of PCL powders is excellent. Differences in the biodegradation of PCL powders with different class were not
observed by the ISO 14851 and ISO/DIS 14855-2. An enzymatic degradation test of PCL powders with different class was studied
using an enzyme of Amano Lipase PS. PCL with smaller particle size was faster degraded by the enzyme. PCL powders with regulated sizes from 125 μm to 250 μm
are proposed as a reference material for the biodegradation test. 相似文献
2.
Takanori Hino Ryuichi Agawa Youichi Moriya Minoru Nishida Yasuhiro Tsugita Takao Araki 《Journal of Material Cycles and Waste Management》2009,11(1):42-54
Waste printed circuit boards contain valuable metals such as Au, Pd, Ag, and Cu that can be reutilized and harmful elements
such as Pb, Br, and Cr that must be removed from the viewpoint of environmental conservation. In this research, we examined
a method that separates the materials from printed circuit boards contained in discarded personal computers. After cutting
the printed circuit boards to a size of 20 × 20 mm, they were heated at 873 K under an Ar atmosphere to remove organic resins
containing elements such as C, H, and N. After heat treatment, the printed circuit boards were crushed using a planetary ball
mill and the pulverized powders were filtered. The fraction with a granularity of greater than 250 μm was separated into magnetic
and nonmagnetic materials by a magnetic field. Because the fraction with a granularity of less than 250 μm contained 39 mass%
of C, it was heated at 1273 K in an atmosphere of 95% Ar and 5% O2 to allow carbon combustion to take place, followed by metal reduction processing at the same temperature in an atmosphere
of 97% Ar and 3% H2. The basicity of the resulting powder was adjusted and the powder was heated at 1773 K under an Ar atmosphere. The proposed
method separated the slag and metal, and 80% of the valuable metals contained in printed circuit boards could be collected. 相似文献
3.
C. Eyholzer P. Tingaut T. Zimmermann K. Oksman 《Journal of Polymers and the Environment》2012,20(4):1052-1062
Bionanocomposites of poly(lactic acid) (PLA) and chemically modified, nanofibrillated cellulose (NFC) powders were prepared by extrusion, followed by injection molding. The chemically modified NFC powders were prepared by carboxymethylation and mechanical disintegration of refined, bleached beech pulp (c-NFC), and subsequent esterification with 1-hexanol (c-NFC-hex). A solvent mix was then prepared by precipitating a suspension of c-NFC-hex and acetone-dissolved PLA in ice-cold isopropanol (c-NFC-hexsm), extruded with PLA into pellets at different polymer/fiber ratios, and finally injection molded. Dynamic mechanical analysis and tensile tests were performed to study the reinforcing potential of dried and chemically modified NFC powders for PLA composite applications. The results showed a faint increase in modulus of elasticity of 10?% for composites with a loading of 7.5?% w/w of fibrils, irrespective of the type of chemically modified NFC powder. The increase in stiffness was accompanied by a slight decrease in tensile strength for all samples, as compared with neat PLA. The viscoelastic properties of the composites were essentially identical to neat PLA. The absence of a clear reinforcement of the polymer matrix was attributed to poor interactions with PLA and insufficient dispersion of the chemically modified NFC powders in the composite, as observed from scanning electron microscope images. Further explanation was found in the decrease of the thermal stability and crystallinity of the cellulose upon carboxymethylation. 相似文献
4.
Masao Kunioka Fumi Ninomiya Masahiro Funabashi 《Journal of Polymers and the Environment》2007,15(4):281-287
The biobased contents of raw materials such as starches, sugar, chitin, or wood powders for biomass plastics were measured
using Accelerator Mass Spectrometry (AMS) based on ASTM D6866. AMS measures the isotope carbon ratio of 14C to 12C and 13C in graphite derived from sample powders. The biobased contents of starches, sugar or chitin were almost 100% which means
that they are fully biobased. The biobased contents of the wood powders were over 140% due to the effect of the post 1950s
14C injection due to nuclear testing. Poly(ε-caprolactone) (PCL) composite samples were prepared using the polymerization and
direct molding method. The starting compound was the ε-caprolactone monomer liquid combined with cellulose and inorganic fillers
using aluminum triflate as a catalyst at 80 °C for 6 or 24 h. PCL cylinder-shaped composite samples with a homogeneously dispersed
cellulose filler were prepared with Mn = 4,600 (Mw/Mn = 2.9). The biobased content of the PCL composite with 50 wt% cellulose filler (51.67%) measured using AMS was slightly higher
than the carbon ratio of cellulose in the starting powder samples (41.3 mol%). This is due to the higher biobased content
(112.70%) of the cellulose filler used in this study. The biobased content of the polymer composite powders by AMS was found
not to be affected by the presence of inorganic fillers, such as talc. 相似文献
5.
Cameron Way Katherine Dean Dong Yang Wu Enzo A. Palombo 《Journal of Polymers and the Environment》2011,19(4):849-862
Polylactic acid (PLA)—maple fibre composites have been synthesised using a series of sequentially modified cellulose fibres
(namely alkylation followed by either acetylation or silanation). Confirmations of the sequential modifications were made
using Fourier Transform Infrared Spectroscopy and Inductively Coupled Plasma—Atomic Emission Spectroscopy and the new surface
morphologies analysed using Scanning Electron Microscopy. The key advantage of the use of sequential treatments (with initial
alkali treatment) was the allowance for direct grafting of suitable chemical groups onto the cellulose in the fibre due to
the removal of lignin, hemicellulose and other surface impurities. However, a balance was found to exist between alkali exposure
time, concentration and resulting fibre integrity. The conditions used resulted in a loss in fibre weight, fibre moisture
content and tensile strength. Sequential treatments with acetylation or silane resulted in a 15–21% strength recovery from
that of the alkali treated composite. Factors that influenced this recovery in strength were the improved fibre-polymer interface,
namely the hydrophilic balancing of the fibres and this further affected the thermal-hydrolysis of the PLA during composite
fabrication. 相似文献
6.
Jonathan Mitchell Luc Vandeperre Rob Dvorak Ed Kosior Karnik Tarverdi Christopher Cheeseman 《Waste management (New York, N.Y.)》2014,34(11):2113-2119
The majority of disposable cups are made from paper plastic laminates (PPL) which consist of high quality cellulose fibre with a thin internal polyethylene coating. There are limited recycling options for PPLs and this has contributed to disposable cups becoming a high profile, problematic waste. In this work disposable cups have been shredded to form PPL flakes and these have been used to reinforce polypropylene to form novel paper plastic composites (PPCs). The PPL flakes and polypropylene were mixed, extruded, pelletised and injection moulded at low temperatures to prevent degradation of the cellulose fibres. The level of PPL flake addition and the use of a maleated polyolefin coupling agent to enhance interfacial adhesion have been investigated. Samples have been characterised using tensile testing, dynamic mechanical analysis (DMA) and thermogravimetric analysis. Use of a coupling agent allows composites containing 40 wt.% of PPL flakes to increase tensile strength of PP by 50% to 30 MPa. The Young modulus also increases from 1 to 2.5 GPa and the work to fracture increases by a factor of 5. The work demonstrates that PPL disposable cups have potential to be beneficially reused as reinforcement in novel polypropylene composites. 相似文献
7.
Hisaaki Yagi Fumi Ninomiya Masahiro Funabashi Masao Kunioka 《Journal of Polymers and the Environment》2012,20(3):673-680
The anaerobic biodegradation rates of four different sizes of poly (lactic acid) (PLA) films (thickness 25???m) in anaerobic sludge at 55?°C were examined. The anaerobic biodegradation rates of small pieces of PLA film were slower than for large pieces of PLA film. We also examined whether PLA film could also be used as a reference material in the anaerobic biodegradation test in addition to PLA powder. The anaerobic biodegradation rate of PLA film became slower with lower activity sludge, but the rate of decrease was gradual, and the anaerobic biodegradation rate of PLA film was faster than the PLA powder (125?C250???m). The anaerobic biodegradation rate of the PLA powder (125?C250???m) reflected the plastic anaerobic biodegradation activity of the sludge more accurately than the thin PLA film (thickness 25???m). Consequently, PLA powder (125?C250???m) is more suitable than thin PLA film (thickness?<?25???m) for use as a reference material to assess the plastic anaerobic biodegradation activity of the sludge in an anaerobic biodegradation test at 55?°C. 相似文献
8.
This paper investigates and compares the performances of polylactic acid (PLA)/kenaf (PLA-K) and PLA/rice husk (PLA-RH) composites
in terms of biodegradability, mechanical and thermal properties. Composites with natural fiber weight content of 20% with
fiber sizes of less than 100 μm were produced for testing and characterization. A twin-screw extrusion was used to compound
PLA and natural fibers, and extruded composites were injection molded to test samples. Flexural and Izod impact test, TGA,
soil burial test and SEM were used to investigate properties. All results were compared to a pure PLA matrix sample. The flexural
modulus of the PLA increased with the addition of natural fibers, while the flexural strength decreased. The highest impact
strength (34 J m−1), flexural modulus (4.5 GPa) and flexural strength (90 MPa) were obtained for the composite made of PLA/kenaf (PLA-K), which
means kenaf natural fibers are potential to be used as an alternative filler to enhance mechanical properties. On the other
hand PLA-RH composite exhibits lower mechanical properties. The impact strength of PLA has decreased when filled with natural
fibers; this decrease is more pronounced in the PLA-RH composite. In terms of thermal stability it has been found that the
addition of natural fibers decreased the thermal stability of virgin PLA and the decrement was more prominent in the PLA-RH
composite. Biodegradability of the composites slightly increased and reached 1.2 and 0.8% for PLA-K and PLA-RH respectively
for a period of 90 days. SEM micrographs showed poor interfacial between the polymer matrix and natural fibers. 相似文献
9.
Ian Colbeck Zaheer Ahmad Nasir Shahida Hasnain Sikander Sultan 《Water, Air, & Soil Pollution: Focus》2008,8(1):61-69
In the developing world, the vast majority of people rely on solid biomass fuels for cooking and heating which results in
poor indoor air quality. The present study determined indoor air quality in some rural and urban areas of Pakistan. Measurements
were made of particulate mass (PM10, PM2.5 and PM1), number concentration and bioaerosols in different micro environments.
PM10 concentrations of up to 8,555 μg/m3 were observed inside the kitchens where biofuels were used as energy source. Cleaning and smoking was identified as a major
source of indoor particulate pollution and concentrations of more than more than 2,000 μg/m3 were recorded in the living room during these activities. Indoor number concentrations in Lahore were typically greater than
those observed outdoors in European cites. At a rural site the highest Colony Forming Units (CFUs) were in the 0.5 μm–2 μm
size fraction, while at the urban location CFUs were dominant for 2 μm–16 μm. It was observed that CFUs(Colony Forming Units)
counts were higher inside living rooms than kitchens. It is important to note that women and children were exposed to extremely
high levels of particulates during cooking. Overall, indoor air quality in Pakistan was poor and there is a dire need to take
a serious step to combat with it. 相似文献
10.
Marco Iotti Paola Fabbri Massimo Messori Francesco Pilati Patrizia Fava 《Journal of Polymers and the Environment》2009,17(1):10-19
Organic–inorganic hybrid coatings based on poly(ε-caprolactone), poly(ethylene oxide) or poly(lactic acid) as organic phase
and silica from tetraethoxysilane as inorganic phase were prepared by the sol–gel approach. Coatings were applied onto poly(lactic
acid) films for food packaging in order to improve its barrier properties towards oxygen and water vapour. All the prepared
coatings were dense, homogeneous layers characterized by a good adhesion to the substrate. The permeance of the coating layers
resulted one order of magnitude lower than that of the uncoated poly(lactic acid) (PLA) film. The hydrophilic character of
the coating did not permit to gain a significant decrease in the water vapour permeance. The perfect visual transparency of
the coatings allows their application without worsening of the esthetical properties of the substrate PLA film. 相似文献
11.
Merlin Aydın Hale Tozlu Sebnem Kemaloglu Ayse Aytac Guralp Ozkoc 《Journal of Polymers and the Environment》2011,19(1):11-17
In this study, the influence of alkali (NaOH) treatment on the mechanical, thermal and morphological properties of eco-composites
of short flax fiber/poly(lactic acid) (PLA) was investigated. SEM analysis conducted on alkali treated flax fibers showed
that the packed structure of the fibrils was deformed by the removal non-cellulosic materials. The fibrils were separated
from each other and the surface roughness of the alkali treated flax fibers was improved. The mechanical tests indicated that
the modulus of the untreated fiber/PLA composites was higher than that of PLA; on the other hand the modulus of alkali treated
flax fiber/PLA was lower than PLA. Thermal properties of the PLA in the treated flax fiber composites were also affected.
Tg values of treated flax fiber composites were lowered by nearly 10 °C for 10% NaOH treatment and 15 °C for 30% NaOH treatment.
A bimodal melting behavior was observed for treated fiber composites different than both of neat PLA and untreated fiber composites.
Furthermore, wide angle X-ray diffraction analysis showed that the crystalline structure of cellulose of flax fibers changed
from cellulose-I structure to cellulose-II. 相似文献
12.
Characterization of Atrazine-Loaded Biodegradable Poly(Hydroxybutyrate-Co-Hydroxyvalerate) Microspheres 总被引:2,自引:0,他引:2
Renato Grillo Nathalie F. S. de Melo Renata de Lima Roberto Wagner Lourenço André Henrique Rosa Leonardo Fernandes Fraceto 《Journal of Polymers and the Environment》2010,18(1):26-32
Polyhydroxybutyrate-co-hydroxyvalerate microspheres (PHBV-MS) were prepared as a delivery system for the herbicide atrazine
(ATZ). Characterization of the system included investigation of in vitro release properties and genotoxicity. ATZ − PHBV-MS
particle diameters showed a size distribution range of 1–13 μm. Differential scanning calorimetry analyses indicated that
ATZ was associated with the PHBV microparticles. The release profiles showed a different release behavior for the pure herbicide
in solution, as compared with that containing ATZ-loaded PHBV-MS. Korsmeyer–Peppas model analyses showed that atrazine release
from the microparticles occurred by a combination of diffusion through the matrix and partial diffusion through water-filled
pores of the PHBV microparticles. A Lactuca sativa test result showed that the genotoxicity of ATZ-loaded PHBV-MP was decreased in relation to ATZ alone. The results demonstrate
a viable biodegradable herbicide release system using atrazine for agrochemical purposes. 相似文献
13.
Wenzhu Ouyang Yong Huang Hongjun Luo Dongshan Wang 《Journal of Polymers and the Environment》2012,20(1):1-9
“Green”/bio-based blends of poly(lactic acid) (PLA) and cellulolytic enzyme lignin (CEL) were prepared by twin-screw extrusion
blending. The mechanical and thermal properties and the morphology of the blends were investigated. It was found that the
Young’s modulus of the PLA/CEL blends is significantly higher than that of the neat PLA and the Shore hardness is also somewhat
improved. However, the tensile strength, the elongation at break, and the impact strength are slightly decreased. Thermogravimetric
analysis (TGA) shows that the thermal stability of the PLA is not significantly affected by the incorporation of the CEL,
even with 40 wt% CEL. The results of FT-IR and SEM reveal that the CEL and the PLA are miscible and there are efficient interactions
at the interfaces between them. These findings show that the CEL is a kind of feasible filler for the PLA-based blends. 相似文献
14.
Zakaria Man Nawshad Muhammad Ariyanti Sarwono Mohamad Azmi Bustam M. Vignesh Kumar Sikander Rafiq 《Journal of Polymers and the Environment》2011,19(3):726-731
In this paper cellulose nanocrystals were prepared by treating microcrystalline cellulose with 1-butyl-3-methylimidazolium
hydrogen sulphate ionic liquid. Cellulose nanocrystals, after separation from ionic liquid, were characterized by X-ray diffraction
(XRD), Fourier transform infrared (FTIR), Field emission scanning electron microscopy (FESEM) Transmission Electron Microscope
(TEM) and Thermogravimetric analysis. XRD results showed no changes in type of cellulose after the treatment with ionic liquid,
however, high crystallinity index was observed in the ionic liquid treated sample. Cellulose nanocrystals, having length around
50–300 nm and diameter around 14–22 nm were observed in the ionic liquid treated sample under FESEM and TEM, and similar patterns
of peaks as that of microcrystalline cellulose were observed for cellulose nanocrystals in the FTIR spectra. The thermal stability
of the cellulose nanocrystals was measured low as compare to microcrystalline cellulose. 相似文献
15.
Kisei Kinoshita Wang Ning Zhang Gang Andrew Tupper Naoko Iino Satoshi Hamada Satoshi Tsuchida 《Water, Air, & Soil Pollution: Focus》2005,5(3-6):89-100
Monitoring of Asian dust at two stations in Changchun, Jilin Province in northeast China, and Kagoshima, southwest Japan,
is discussed. In Changchun, interval records were made with digital and video cameras from 18 March 2003. In Kagoshima, a
web camera system to monitor volcanic clouds has been working since December 2000, which also provides data for studies of
dust. A heavy dust episode on 11 November 2002, affecting both stations, was detected using 11 and 12 μm channels of NOAA/AVHRR.
We observed dust in Changchun on 26 March, 7, 14–16 April, 1–2, 8, 10, 19 May, 8, 23 June, and 12 July in 2003. The observed
images corresponded well to NOAA/AVHRR imagery and with 8.6, 11 and 12 μm Terra/MODIS results, although conditions were too
cloudy for satellite verification in some cases. 相似文献
16.
Measurements of aerosol size-separated number concentrations were performed in March 2001 on the Tama Hills of Japan, located
near regions of heavy industry. The concentrations of particles larger than 1.0 μ m in diameter dramatically increased during
the Kosa phenomena on 6–8 and 18–24 March. The number concentrations of coarse particles (> 3.0 μm) showed distinct diurnal
variations, especially during the Kosa events. Fine particles smaller than 0.5 μm increased when the relative humidity was
high and the wind speed was low. On the other hand, the coarse particles concentrations were well correlated with wind speed
and temperature. The dry deposition velocity of the coarse particles at the forest canopy was estimated from the nighttime
decrease in the number concentrations. 相似文献
17.
Masahiro Funabashi Fumi Ninomiya Edgar Dulay Flores Masao Kunioka 《Journal of Polymers and the Environment》2010,18(2):85-93
The evaluation method of biomass carbon ratio of polymer composite samples including organic and inorganic carbons individually
was investigated. Biodegradable plastics and biobased plastics can have their mechanical properties improved by combining
with inorganic fillers. Polymer composites consisting of biodegradable plastics and carbonate were prepared by two different
methods. Poly(lactic acid) (PLA) composite was prepared by synthesis from l-lactide with catalyst and calcium carbonate (CaCO3) powders from lime. Poly(butylene succinate) (PBS) composite was prepared by hot-pressing the mixture of PBS powder and CaCO3 powders from oyster shells. The mechanical properties of composite samples were investigated by a tensile test and a compression
test using an Instron type mechanical tester. Tensile test with a dumbbell shape specimen was performed for PBS composite
samples and compression test with a column shape specimen for PLA composite samples. Strength, elastic modulus and fracture
strain were obtained from the above tests. Biomass carbon ratio is regulated in the American Standards for Testing and Materials
(ASTM). In ASTM standards on biomass carbon ratio, it is required that carbon atoms from carbonates, such as CaCO3, are omitted. Biomass carbon ratio was evaluated by ratio of 14C to 12C in the samples using Accelerator Mass Spectrometry (AMS). The effect of pretreatment, such as oxidation temperature and
reaction by acid, on results of biomass carbon ratio was investigated. Mechanical properties decrease with increasing CaCO3 content. The possibility of an evaluation method of biomass carbon ratio of materials including organic and inorganic carbons
was shown. 相似文献
18.
Effect of Orientation on the Morphology and Mechanical Properties of PLA/Starch Composite Filaments 总被引:1,自引:0,他引:1
Randal L. Shogren Gordon Selling J. L. Willett 《Journal of Polymers and the Environment》2011,19(2):329-334
Polylactic acid (PLA)/starch fibers were produced by twin screw extrusion of PLA with granular or gelatinized starch/glycerol
followed by drawing through a set of winders with an intermediate oven. At 30% starch, fibers drawn 2–5x were highly flexible
(elongation 20–100%) while undrawn filaments were brittle (elongation 2–9%). Tensile strength and moduli increased with increasing
draw ratio but decreased with increasing starch content. Mechanical properties were better for composites made with gelatinized
starch/glycerol than granular starch. In conclusion, orientation greatly increases the flexibility of PLA/starch composites
and this may be useful not only in fibers but also possibly in molded articles. Other advantages of starch addition could
include fiber softness without added plasticizer, moisture/odor absorbency and as a carrier for active compounds. 相似文献
19.
In this research, a two-step process consisting of vacuum pyrolysis and vacuum centrifugal separation was employed to treat waste printed circuit boards (WPCBs). Firstly, WPCBs were pyrolysed under vacuum condition at 600 °C for 30 min in a lab-scale reactor. Then, the obtained pyrolysis residue was heated under vacuum until the solder was melted, and then the molten solder was separated from the pyrolysis residue by the centrifugal force. The results of vacuum pyrolysis showed that the type-A of WPCBs (the base plates of which was made from cellulose paper reinforced phenolic resin) pyrolysed to form an average of 67.97 wt.% residue, 27.73 wt.% oil, and 4.30 wt.% gas; and pyrolysis of the type-B of WPCBs (the base plates of which was made from glass fiber reinforced epoxy resin) led to an average mass balance of 72.20 wt.% residue, 21.45 wt.% oil, and 6.35 wt.% gas. The results of vacuum centrifugal separation showed that the separation of solder was complete when the pyrolysis residue was heated at 400 °C, and the rotating drum was rotated at 1200 rpm for 10 min. The pyrolysis oil and gas can be used as fuel or chemical feedstock after treatment. The pyrolysis residue after solder separation contained various metals, glass fibers and other inorganic materials, which could be recycled for further processing. The recovered solder can be reused directly and it can also be a good resource of lead and tin for refining. 相似文献
20.
Yasunori Kawagoshi Isao Fukunaga Hisao Itoh 《Journal of Material Cycles and Waste Management》1999,1(1):53-61
Organophosphoric acid triester (OPE) concentration levels in water and bottom sediment at the Osaka North Port Sea-Based Solid
Waste Disposal Site were investigated, and the behavior of OPEs in the water environment of the waste disposal site was examined.
The more highly water-soluble OPEs were frequently detected in raw water. Of the OPEs detected, TCEP and TCPP showed very
high concentrations (1.0–90 μg/l), followed by TEP (0.3–10 μg/l) > TBXP (0.8–6.3 μg/l) > TDCPP (0.6–6.2 μg/l) > TBP (0.2–1.5 μg/l)
> TPP (<0.1 μg/l). Most OPEs detected in water were eluted from the disposal waste to the water phase immediately and behaved
as dissolved forms with no distribution in suspended solids (SS). On the other hand, the less water-soluble OPEs, such as
TCP or TEHP, were detected in bottom sediment but hardly at all in water samples. All OPEs were detected at the waste disposal
site, within which their concentration levels were uniform. It appeared that the less water-soluble OPEs were present as SS-associated
forms and behaved in line with the floating surface sludge at the bottom.
Received: July 6, 1998 / Accepted: February 25, 1999 相似文献