共查询到20条相似文献,搜索用时 15 毫秒
1.
Vanessa Cheesbrough Kurt A. Rosentrater Jerry Visser 《Journal of Polymers and the Environment》2008,16(1):40-50
Interest in renewable biofuel sources has intensified in recent years, leading to greatly increased production of ethanol
and its primary coproduct, Distillers Dried Grain with Solubles (DDGS). Consequently, the development of new outlets for DDGS
has become crucial to maintaining the economic viability of the industry. In light of these developments, this preliminary
study aimed to determine the suitability of DDGS for use as a biofiller in low-cost composites that could be produced by rapid
prototyping applications. The effects of DDGS content, particle size, curing temperature, and compression on resulting properties,
such as flexural strength, modulus of elasticity, water activity, and color were evaluated for two adhesive bases. The composites
formed with phenolic resin glue were found to be greatly superior to glue in terms of mechanical strength and durability:
resin-based composites had maximum fiber stresses of 150–380 kPa, while glue composites had values between 6 kPa and 35 kPa;
additionally, glue composites experienced relatively rapid microbial growth. In the resin composites, both decreased particle
size and increased compression resulted in increased mechanical strength, while a moderate DDGS content was found to increase
flexural strength but decrease Young’s modulus. These results indicate that DDGS has the potential to be used in resin glue-based
composites to both improve flexural strength and improve potential biodegradability. 相似文献
2.
Shaohong Peng Lieqiang Chen Liubin Li Mingquan Xie Huajie Huang Xiaodan Liu 《Journal of Material Cycles and Waste Management》2010,12(2):103-107
The thermal stability and degradation kinetics of TV housing plastic and brominated flame retardants were studied by means
of thermogravimetry. The effects of the treatment temperature on the removal rate of Br were investigated using a tube furnace
reactor under isothermal and vacuum conditions. The results showed that the weight loss of TV housing plastic was divided
into two stages: the thermal degradation of brominated flame retardants mainly occurred at 290°–350°C, and the degradation
of the high-impact polystyrene resin mainly occurred at 350°–455°C. Nearly 90% of Br can be removed from TV housing plastic
when the treatment temperature exceeds 280°C. 相似文献
3.
Viscosity, peel and shear strength of epoxidized natural rubber (ENR)-based pressure-sensitive adhesive was studied by using
hybrid tackifiers consisting of a mixture of coumarone-indene resin and petro resin. The coumarone-indene resin concentration
was fixed at 40 parts per hundred parts of rubber (phr). The concentration of petro resin, however, was varied from 20 to
80 phr. Toluene and polyethylene terephthalate (PET) film were used as the solvent and coating substrate respectively throughout
the experiment. Viscosity of adhesive was determined by a HAAKE Rotary Viscometer whereas peel and shear strength was measured
by a Lloyd Adhesion Tester. Results show that viscosity and shear strength decreases with increasing petro resin concentration.
However, peel strength exhibits a maximum value at 40 phr petro resin, an observation which is attributed to maximum wettability
and compatibility of adhesive on the substrate. ENR 25-based adhesive exhibits higher viscosity and peel strength but lower
shear strength compared to the ENR 50 adhesive system. 相似文献
4.
The effect of molecular weight and testing rate on peel and shear strength of epoxidized natural rubber (ENR-50)-based adhesive
was investigated using petro resin as the tackifier. Toluene and polyethylene terephthalate were used as the solvent and substrate
respectively. Peel and shear strength were determined by a Llyod Adhesion Tester operating at different rates of testing.
Result shows that peel strength and shear strength increases up to an optimum molecular weight of 4.2 × 104 g/mol of ENR-50. This observation is attributed to the combined effects of wettability and mechanical strength of rubber
for peel strength. For shear strength, it is ascribed to the optimum cohesive and adhesive strength. Both peel strength and
shear strength increases with increasing rate of testing, an observation which is associated to the viscoeslastic response
of the adhesive. Thermal study, SEM and FTIR study confirms the miscibility of tackifier with ENR-50. 相似文献
5.
Altaf H. Basta Houssni El-Saied Jerrold E. Winandy Ronald Sabo 《Journal of Polymers and the Environment》2011,19(2):405-412
Investigations have continued for production high performance agro-based composites using environmentally acceptable approaches.
This study examines the role of adding amide-containing biopolymers during synthesis of urea–formaldehyde (UF) on properties
of adhesive produced, especially its adhesion potential. The environmental performance of UF-resin synthesized in the presence
of modified amide-containing biopolymer was evaluated by evaluating the free-HCHO of both adhesive (during processing) and
of the eventual engineered composite product. Also, the benefits of this synthesis-modified adhesive in enhancing the bondability
of sugar-cane fibers used in engineered composite panels was evaluated and compared to using UF-resin. The results obtained
show that, static bending of the produced composites varied from 27.7 to 33.13 N/mm2 of modulus of rupture (MOR) and from 2860 to 3374 N/mm2 of Modulus of Elasticity (MOE); while for internal bond (IB) it’s varied from 0.64 to 0.866 N/mm2. Based on the ANSI and EN Standards modified UF-based agro composites produced meet the performance requirements for high
grade particleboards with respect to static bending strength. These agro-based composite also tested out as having free-HCHO
values of ~13 mg/100 g board. 相似文献
6.
The adhesion properties of magnesium oxide filled epoxidized natural rubber (ENR 25)/acrylonitrile-butadiene rubber (NBR) blend adhesives were studied using petro resin and gum rosin as tackifiers. Toluene was used as the solvent throughout the experiment. Five different loadings, i.e. 10, 20, 30, 40 and 50 phr magnesium oxide was used in the adhesive formulation. The SHEEN hand coater was used to coat the adhesive on polyethylene terephthalate at 30 and 120 µm coating thickness. The tack, peel strength and shear strength were determined by a Lloyd adhesion tester operating at 30 cm min?1. Results shows that all the adhesion properties of the ENR 25/NBR adhesives show a maximum value at 10 phr filler loading. Loop tack and peel strength pass through a maximum, an observation which is associated to the optimum wettability of adhesive on the substrate. For the shear test, maximum shear strength occurs due to the optimum cohesive strength of the adhesive. Results also show that all petro resin based adhesives have higher adhesion properties than gum rosin based adhesive. In all cases, the adhesion properties of adhesives also increase with increasing coating thickness. 相似文献
7.
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
8.
Nona Merry M. Mitan Mihai Brebu Thallada Bhaskar Akinori Muto Yusaku Sakata Mitsuo Kaji 《Journal of Material Cycles and Waste Management》2007,9(1):62-68
Waste DVDs and CDs were thermally degraded at 450°C by a semibatch process. In total, 40–50 wt% was converted into liquid
product that consisted of phenol derivatives (∼75 wt%), bisphenol (∼10 wt%) and its derivatives, and small amounts of aromatic
hydrocarbons such as benzene, toluene, ethylbenzene, dimethylbenzene, methylethylbenzene, diethylbenzene, and methylisopropyl
benzene. Degradation of the polycarbonate support from DVDs and CDs was enhanced by coprocessing with vegetable cooking oil,
the degradation of which gave a homologue series of hydrocarbons and organic acids with up to 25 and 18 atoms of carbon, respectively.
Silver from the reflective coating on DVDs and CDs remained in the solid residue, its concentration increasing about 2.5 times
compared to that of the original disks. 相似文献
9.
Motoyuki Sugano Akihiro Komatsu Masanori Yamamoto Mika Kumagai Takayuki Shimizu Katsumi Hirano Kiyoshi Mashimo 《Journal of Material Cycles and Waste Management》2009,11(1):27-31
Most landfilled plastic waste is a mixture or is in the form of composites with incombustible wastes such as glass, metals,
and ceramics. After hydrothermal treatment, including a steam-explosion process, the separation of mixed waste (MW) into organic
and inorganic substances becomes easy. However, the effect of hydrothermal pretreatment on the subsequent liquefaction of
organic substances from MW is not obvious. In this study, the effects on the liquefaction of polystyrene and high-density
polyethylene are discussed. Moreover, optimum conditions for the liquefaction of organic substances from hydrothermally treated
MW are identified. By means of this hydrothermal pretreatment, including the steam-explosion process, polystyrene and high-density
polyethylene can be significantly converted to oil by liquefaction at 300°–400°C. In comparison with liquefaction of hydrothermally
pretreated mixed waste (HMW) at 300°–400°C with a batch type reactor, the yield of oil increases significantly on liquefaction
using a semi-batch type reactor. It is considered that the radical chain and termination reactions among the radicals from
HMW were inhibited in the semi-batch type reactor. On liquefaction of HMW in a semi-batch reactor, the conversion of HMW to
oil was enhanced on increasing the liquefaction temperature to 350°C and the holding time to 60 min.
Chemical Feedstock Recycling & Other Innovative Recycling Techniques 6 相似文献
10.
Masturi Mikrajuddin Abdullah Khairurrijal 《Journal of Material Cycles and Waste Management》2011,13(3):225-231
Simple mixing and hot pressing methods were used to make composites from home waste—in particular, paper and dry leaves—using
polyvinyl acetate (PVAc) as an adhesive and silica nanoparticles as filler. The optimum composition for the strongest composites,
in terms of compressive strength, had a mass ratio of silica nanoparticles/PVAc/(paper + dry leaves) of 3:80:280. With this
mass ratio, a compressive strength of 68.50 MPa was obtained for samples prepared at a pressing temperature of 150°C, pressing
pressure of 100 MPa, and pressing time of 20 min. The addition of silica nanoparticles increased the compressive strength
by about 50%, compared with composites made without the addition of nanosilica (45.60 MPa). Higher compressive strength was
obtained at a higher pressing pressure. At a pressing pressure of 120 MPa, pressing temperature of 150°C, and pressing time
of 20 min, a compressive strength of 69.10 MPa was obtained. When the pressing time was increased to 45 min at a pressing
pressure of 120 MPa, a compressive strength of 84.37 MPa was measured. A model was also proposed to explain the effects of
pressing pressure and pressing time on compressive strength. The model predictions were in good agreement with the experimental
data. 相似文献
11.
Farhana Gul-E-Noor Mubarak A. Khan Sushanta Ghoshal Ruhul A. Khan Russel A. Mazid A. M. Sarwaruddin Chowdhury 《Journal of Polymers and the Environment》2010,18(3):224-230
Thin films of gelatin were prepared by casting. Then the films were photocured and the mechanical properties were studied.
The tensile strength of UV cured gelatin films showed about 10% enhancement than that of raw gelatin films. Minor amount of
urea (1–5%) was used as additive in aqueous gelatin solution and films were prepared using same technique. Four formulations
were prepared in methanol with 2-ethylhexyl acrylate in the presence of photoinitiator (darocur-1664). The films were soaked
in the prepared formulations and then cured under UV radiation at different intensities (5–25 passes). Percentage of urea,
monomer concentration, soaking time and radiation intensities were optimized with the extent of polymer loading, TS and elongation
at break of the photocured film. The films containing 2% urea, cured with 3% EHA for 3 min at 15th UV pass showed the highest
mechanical properties. A significant improvement of TS (31%) occurred when EHA (3%) was incorporated. 相似文献
12.
Jiří Pšeja Josef Hrnčiřík Jan Kupec Hana Charvátová Petr Hruzík Michael Tupý 《Journal of Polymers and the Environment》2006,14(3):231-237
Biodegradability testing was performed in an aqueous environment under anaerobic conditions after inoculation with digested sludge from municipal wastewater treatment plant. In cross-linking with 1,2:3,4-diepoxybutane in limits 0.8–9.1% weight, biodegradability degree decreased from 76.8 to 62.2%; when 1,2:7,8 diepoxyoctane in quantities 1.1–13.2% weight was used, biodegradability degree dropped more prominently – from 72.3 to 22.8%. There is obviously a direct connection between growing cross-link degree (assessed by so-called fixation index) and decreasing readiness to biodegradation, apparently owing to build-up of a network forming an obstacle to access of micro-organisms and enzymes. 相似文献
13.
Demetres Briassoulis Epifania Babou Miltiadis Hiskakis 《Journal of Polymers and the Environment》2011,19(2):341-361
The field performance of experimental biodegradable drip irrigation thin wall and regular pipes was investigated through three
sets of full-scale experiments and in the laboratory. These experimental biodegradable drip irrigation systems were produced
through the processing of biodegradable under real soil conditions polymers, Mater-Bi and Bioflex. The mechanical behaviour
of the biodegradable thin wall pipes during the irrigation period was more unstable when compared to the corresponding behaviour
of the rigid pipes. The tensile strength of the Mater-Bi and Bioflex thin wall pipes remained almost constant during the total
exposure time, except from the folding areas. During the first 7–23 days of exposure in the field, the thin wall pipes had
already lost more than the 50% of their initial elongation at break value due to degradation. However, their hydraulic performance
began to decline only after a period of 100–120 days with the simultaneous formation of the first cracks. Likewise, the majority
of the series of biodegradable rigid pipes exhibited a remarkable reduction in their elongation at break values in the transverse
direction within the first 2 weeks. Despite the significant drop of the elongation at break, all biodegradable rigid pipes
generally retained their tensile strength as well as a satisfactory hydraulic performance during almost the whole duration
of their exposure. A few premature leakages in some points adjoining the drippers were observed after 8–10 weeks of exposure. 相似文献
14.
Soy protein plastics are a renewable, biodegradable alternative to fossil fuel-based plastic resins. Processing of soy protein
plastics using conventional methods (injection molding, extrusion) has met with some success. Viscosities of processable formulations
that contain soy protein along with the necessary additives, such as glycerol and cornstarch, have not been reported, but
are necessary for extrusion modeling and the design of extrusion dies. Resins consisting of soy protein isolate-cornstarch
ratios of 4:1, 3:2, and 2:3 were plasticized with glycerol and soy oil, compounded in a twin screw extruder and adjusted to
10% moisture. The effects on viscosity of added sodium sulfite, a titanate coupling agent and recycling were evaluated using
a screw-driven capillary rheometer at shear rates of 100–800/s. The viscosities fit a power-law model and were found to be
shear thinning with power-law indices, n, of 0.18–0.46 and consistency indices, m, of 1.1 × 104–1.0 × 105. Power-law indices decreased and consistency indices increased with increasing soy protein-to-cornstarch ratio and in the
absence of sodium sulfite. Addition of the titanate coupling agent resulted in increased power-law index and decreased consistency
index. Viscosities at a shear rate of 400/s decreased with recycling, except for the 4:1 soy protein isolate to cornstarch
formulation, which displayed evidence of wall slip. Power-law indices were unaffected by recycling. Viscosities in the tested
shear rate range were comparable to polystyrene and low-density polyethylene indicating soy protein plastics are potential
drop-in replacements for commodity resins on conventional plastics processing equipment. 相似文献
15.
C. K. Ngan U. B. Cheah W. Y. Wan Abdullah K. P. Lim B. S. Ismail 《Water, Air, & Soil Pollution: Focus》2005,5(1-2):125-136
The fate of chlorothalonil, chlorpyrifos and profenofos in sandy loam soil under tropical condition was studied in a vegetable
plot in the Cameron Highlands, Malaysia. The plot was treated with chlorothalonil, chlorpyrifos and profenofos according to
normal agricultural practices of the Cameron Highlands. Water (runoff and lysimeter), soil and bedload sediment samples were
taken according to a sampling schedule. Residues in water, soil and bedload sediment samples were laboratory analysed to determine
amount. Chlorothalonil residues were detected in the range of < 0.01–0.08 mg/kg in the soil, < 0.01–0.02 ng/mL in the leachate,
< 0.01–0.02 ng/mL in the runoff and < 0.01–0.11mg/kg in the sediment. Field studies of chlorpyrifos showed residue levels
of < 0.01–0.06 mg/kg in the soil, < 0.01–0.07 ng/mL in the leachate, < 0.01–0.08 ng/mL in the runoff and < 0.01–0.62 mg/kg
in the sediment. Residue levels of profenofos were detected in the range of < 0.01–0.02 mg/kg in the soil, < 0.01–0.87 ng/mL
in the leachate, < 0.01–0.08 ng/mL in the runoff and < 0.01–0.35 mg/kg in the sediment. The three pesticides dissipated rapidly,
with DT50 (time for 50% loss) of less than two days. The study showed that these pesticides dissipated rapidly under the climatic
conditions of the Cameron Highlands in Malaysia. 相似文献
16.
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
17.
Toshiro Tsuji Yoshiki Tanaka Hironori Itoh 《Journal of Material Cycles and Waste Management》2001,3(1):2-7
Plastic pellets of polyethylene (PE), polypropylene (PP), and polystyrene (PS) were gasified in a two-stage thermal degradation
process. The first stage is the conversion of polyolefins to distilled oils using a melting vessel. In the second stage, the
oils from the first stage are gasified using a tubular reactor. The distilled oil yields of PE, PP, and PS in the first stage
were 84, 89, 92 wt%, respectively, each at 470°C. The total gas yields of PE, PP, and PS in the second stage were 80, 74,
and 6.2 wt%, respectively, each at 800°C. The main components of the product gas for PE and PP were methane and olefins such
as ethene and propene. Some aromatic oils, including benzene, toluene, and xylene, were also produced as by-products. The
amount of carbonaceous residue, or coke, was very low (less than 1 wt%). By dividing the process into two stages, the coking
rate was considerably reduced compared with direct gasification of the polyolefins.
Received: July 19, 2000 / Accepted: September 17, 2000 相似文献
18.
Christopher Thellen Megan Coyne Danielle Froio Margaret Auerbach Carl Wirsen Jo Ann Ratto 《Journal of Polymers and the Environment》2008,16(1):1-11
A series of polyhydroxyalkanoates (PHA), all containing 1% nucleating agent but varying in structure, were melt-processed
into films through single screw extrusion techniques. This series consisted of three polyhydroxybutyrate (PHB) and three polyhydroxybutyrate-valerate
(PHBV) resins with varying valerate content. Processing parameters of temperature in the barrel (165–173 °C) and chill rolls
(60 °C) were optimized to obtain cast films. The gel-permeation chromatography (GPC) results showed a loss of 8–19% of the
polymer’s initial molecular weight due to extrusion processing. Modulated differential scanning calorimetry (MDSC) displayed
glass transition temperatures of the films ranging from −4.6 to 6.7 °C depending on the amount of crystallinity in the film.
DSC data were also used to calculate the percent crystallinity of each sample and slightly higher crystallinity was observed
in the PHBV series of samples. X-ray diffraction patterns did not vary significantly for any of the samples and crystallinity
was confirmed with X-ray data. Dynamic mechanical analysis (DMA) verified the glass transition trends for the films from DSC
while loss modulus (E′) reported at 20 °C showed that the PHBV (3,950–3,600 MPa) had the higher E′ values than the PHB (3,500–2,698 MPa) samples. The Young’s modulus values of the PHB and PHBV samples ranged from 700 to
900 MPa and 900 to 1,500 MPa, respectively. Polarized light microscopy images revealed gel particles in the films processed
through single-screw extrusion, which may have caused diminished Young’s modulus and tensile strength of these films. The
PHBV film samples exhibited the greatest barrier properties to oxygen and water vapor when compared to the PHB film samples.
The average oxygen transmission rate (OTR) and water vapor transmission rate (WVTR) for the PHBV samples was 247 (cc-mil/m2-day) and 118 (g-mil/m2-day), respectively; while the average OTR and WVTR for the PHB samples was 350 (cc-mil/m2-day) and 178 (g-mil/m2-day), respectively. Biodegradation data of the films in the marine environment demonstrated that all PHA film samples achieved
a minimum of 70% mineralization in 40 days when run in accordance with ASTM 6691. For static and dynamic incubation experiments
in seawater, microbial action resulting in weight loss as a function of time showed all samples to be highly biodegradable
and correlated with the ASTM 6691 biodegradation data. 相似文献
19.
以大孔型磺酸基聚苯乙烯阳离子树脂为载体,采用硝酸银溶液浸渍、硼氢化钠溶液还原制备了纳米银负载型阳离子交换树脂,并对其吸附去除水中碘离子的性能进行了研究。结果表明:最佳硝酸银浸渍浓度为10 mmol/L,对应载银量19.3 mg/g;25 ℃中性水溶液中,该材料对碘离子的饱和吸附量为74.7 mg/g;吸附量受溶液离子强度的影响较小,但当溶液pH从11降至3时吸附量降低了23%。根据吸附前后材料的XPS谱图变化推测碘离子的去除机理可能为:树脂载体上负载的纳米银活性组分首先与水中溶解氧发生氧化反应产生银离子,随后与溶液中的碘离子结合形成AgI沉淀,从而将碘离子从溶液中去除。 相似文献
20.
V. L. Finkenstadt C.-K. Liu P. H. Cooke L. S. Liu J. L. Willett 《Journal of Polymers and the Environment》2008,16(1):19-26
Sorbitol and glycerol were used to plasticize sugar beet pulp-poly(lactic acid) green composites. The plasticizer was incorporated
into sugar beet pulp (SBP) at 0%, 10%, 20%, 30% and 40% w/w at low temperature and shear and then compounded with poly(lactic
acid) (PLA) using twin-screw extrusion and injection molding. The SBP:PLA ratio was maintained at 30:70. As expected, tensile
strength decreased by 25% and the elongation increased. Acoustic emission (AE) showed correlated debonding and fracture mechanisms
for up to 20% w/w plasticizer and uncorrelated debonding and fracture for 30–40% sorbitol and 30% glycerol content in SBP–PLA
composites. All samples had a well dispersed SBP phase with some aggregation in the PLA matrix. However, at 40% glycerol plasticized
SBP–PLA composites exhibited unique AE behavior and confocal microscopy revealed the plasticized SBP and PLA formed a co-continuous
two phase system.
相似文献
V. L. FinkenstadtEmail: |