共查询到20条相似文献,搜索用时 15 毫秒
1.
Alexander Jones Abhyuday Mandal Suraj Sharma 《Journal of Polymers and the Environment》2018,26(1):132-144
Food preservatives or drug compounds can be eluted from polymer substrates to prevent the occurrence of hospital-acquired infections and food spoilage. We investigated the antimicrobial and drug-elution properties of the albumin and zein thermoplastic blends plasticized with glycerol and mixed with varying amounts of low-density polyethylene (LDPE), food preservatives (sodium benzoate or sodium nitrite), and drugs (ampicillin or ciprofloxacin). Bacillus subtilis and Escherichia coli were utilized as Gram (+) and Gram (?) species, respectively, for antimicrobial and drug-elution analyses, since these species are common in the human body and in food environments. The amount of contamination occurring in food and medical applications could be limited with usage of plastic blends made from thermomechanical molding of proteins (albumin from hen egg white and zein from corn), drug eluting compounds, and low-density polyethylene. 相似文献
2.
C. N. Ludvik G. M. Glenn A. P. Klamczynski D. F. Wood 《Journal of Polymers and the Environment》2007,15(4):251-257
Adding cellulose fiber reinforcement can improve mechanical properties of biodegradable plastics, but fiber must be well dispersed
to achieve any benefit. The approach to dispersing fiber in this study was to use aqueous gels of sodium bentonite clay. These
clay-fiber gels were combined with powdered compostable thermoplastics and calcium carbonate filler. The composite was dried,
twin-screw extruded, and injection molded to make thin parts for tensile testing. An experimental design was used to determine
the effect of fiber concentration, fiber length, and clay concentration. Polybutylene adipate/terephthalate copolymer (PBAT)
and 70/30 polylactic acid (PLA)/PBAT blend were the biodegradable plastics studied. The composite strength decreased compared
to the thermoplastics (13 vs. 19 MPa for PBAT, 27 vs. 38 MPa for the PLA/PBAT blend). The composite elongation to break decreased
compared to the thermoplastics (170% vs. 831% for PBAT, 4.9% vs. 8.7% for the PLA/PBAT blend). The modulus increased for the
composites compared to the thermoplastic standards (149 vs. 61 MPa for PBAT, 1328 vs. 965 MPa for the PLA/PBAT blend). All
composite samples had good water resistance. 相似文献
3.
Saeed Kazemi Najafi 《Waste management (New York, N.Y.)》2013,33(9):1898-1905
The use of recycled and waste thermoplastics has been recently considered for producing wood plastic composites (WPCs). They have great potential for WPCs manufacturing according to results of some limited researches. This paper presents a detailed review about some essential properties of waste and recycled plastics, important for WPCs production, and of research published on the effect of recycled plastics on the physical and mechanical properties of WPCs. 相似文献
4.
Development of polymeric materials that can reduce the reliance on petroleum derived synthetic polymers involves biopolymers such as proteins, starch, cellulose and lipids which can be obtained as agricultural co-products or by-products. Specifically, bioplastics from protein feedstock may have significant advantages over traditional plastics, especially in areas such as packaging, agriculture, horticulture and medical materials. This article focuses on fabricating plastics from whey and albumin proteins and describing properties of plastics made from them. These protein biomasses were plasticized using water and compression molded into plastic samples. Results indicated the importance of water on plasticization during fabrication and on mechanical performance later due to densification during drying. 相似文献
5.
Kristen Kruger Woods Gordon W. Selling Peter H. Cooke 《Journal of Polymers and the Environment》2009,17(2):115-122
Blends of zein and polyvinylpyrrolidone (PVP) were compared based on their tensile properties, thermal properties and morphology.
Zein was blended with polyvinylpyrrolidone of varying molecular weights (10, 55, and 1,300 kDa) and films were cast from ethanol
solutions. Films cast using the higher molecular weight polymers showed an improvement in tensile strength, up to a 24% increase,
compared to control. Differential scanning calorimetry data for the blends showed single Tm and Tg values of an intermediate value between those of zein and PVP control samples. Field emission scanning electron microscopy
images show no obvious inhomogeneities, and confocal fluorescence microscopy showed no decreased uniformity in the PVP/zein
films compared to control. Electrospun fibers of the zein/PVP blends were also obtained. These findings suggest that zein
and polyvinylpyrrolidone combine to form a compatible blend, the first such blend of zein with a synthetic polymer. 相似文献
6.
This paper aims to provide useful knowledge on the use of plastic wastes as additives to coking blends for the production of metallurgical coke. It focuses on the influence that the composition of plastic wastes has upon the development of coal fluidity, the generation of pressure during the coking process and the quality of the cokes produced in a semipilot oven. Several plastic mixtures of two types of thermoplastics, polyolefins (HDPE, LDPE and PP) and aromatic polymers such as PET, were used. The overall addition rate of plastics to a medium-fluid coal blend was 2 wt%. It is shown that polyolefins, weaker modifiers of coal fluidity, may be employed to maintain coke quality but that they have a negative effect on the generation of coking pressure, while plastics of the aromatic type such as PET, a strong modifier of coal fluidity, can be used to counteract the generation of coking pressure. From the results, it is deduced that the protocol developed is useful for determining the optimum amount of each type of polymer (polyolefins and aromatic polymers) that is needed in order to counteract the generation of pressure during the coking process and to maintain the quality of the cokes. 相似文献
7.
Kris E. Spence Jay-lin Jane Anthony L. Pometto Jr 《Journal of Polymers and the Environment》1995,3(2):69-74
Dialdehyde starch (DAS) and zein, a hydrophobic corn protein, were investigated to produce biodegradable plastics with improved water resistance and mechanical properties. In the study, dialdehyde starch and zein ratio, plasticizers, and degree of starch oxidation were examined. Increased molding temperature and level of starch oxidation decreased water absorption of the plastic. Tensile strength and Young's modulus increased with starch oxidation. The biodegradation of starting materials and ground plastic specimens was studied in aerobic soil reactors maintained at 25°C for 180 days. Biodegradation of corn starch, zein, and dialdehyde starch for 180 days produced CO2 equivalent to 64, 63, and 10% of theoretical carbon, respectively. Specimens of molded DAS and zein (3 : 1) plastic showed accelerated CO2 evolution compared to DAS and other raw materials alone. By 180 days, specimens made with starch of low oxidation (1 and 5% oxidized) demonstrated a 60% biodegradation, and specimens with highly oxidized starch (90% oxidized) achieved 37% biodegradation.Paper presented at the Bio/Environmentally Degradable Polymer Society—Third National Meeting, June 6–8, 1994, Boston, Massachusetts.Journal Paper J-15927 of the Iowa Agriculture and Home Economics Experiment Station, Ames, Project No. 3258. 相似文献
8.
Biodegradable Blends Based on Starch and Poly(Lactic Acid): Comparison of Different Strategies and Estimate of Compatibilization 总被引:1,自引:0,他引:1
Emmanuelle Schwach Jean-Luc Six Luc Avérous 《Journal of Polymers and the Environment》2008,16(4):286-297
Finding plastic substitutes based on sustainability, especially for short-term packaging and disposable applications has aroused
scientific interest for many years. Starch may be a substitute for petroleum based plastics but it shows severe limitations
due to its water sensitivity and rather low mechanical properties. To overcome these weaknesses and to maintain the material
biodegradability, one option is to blend plasticized starch with another biodegradable polymer. To improve both the compatibility
between the main phases and the performance of the final blend, different compatibilization strategies are reported in literature.
However, the relative efficiency of each strategy is not widely reported. This paper presents three different strategies:
in situ (i) formation of urethane linkages; (ii) coupling with peroxide between starch and PLA, and (iiii) the addition of
PLA-grafted amylose (A-g-PLA) which has been elaborated ex situ and carefully analyzed before blending. This study compares
the effect of each compatibilization strategy by investigating mechanical and thermal properties of each blend. Compatibilizing
behavior of the A-g-PLA is demonstrated, with a significant increase (up to 60%) in tensile strength of starch/PLA blend with
no decrease in elongation at failure. 相似文献
9.
P. Sarath Sateesh Bonda Smita Mohanty Sanjay K. Nayak 《Journal of Material Cycles and Waste Management》2017,19(4):1391-1399
The plastic components from waste mobile phones were sorted and characterized using visual, spectroscopic and thermal methods. The sustainable strength of the recovered plastics was investigated by comparing their mechanical and thermal properties with commercially used reference materials. The results revealed that the recovered polymers have significant potential to be reused. However, some properties, such as impact strength and tensile modulus, are significantly low compared to virgin materials and need further improvement. The samples were also tested for brominated flame retardants (BFRs) using gas chromatography–mass spectrometry technique, and the results indicated the absence of BFR in recovered plastics; hence, these can be processed without any risk of BFR toxicity. 相似文献
10.
Application of Cellulose Microfibrils in Polymer Nanocomposites 总被引:1,自引:0,他引:1
Cellulose microfibrils obtained by the acid hydrolysis of cellulose fibers were added at low concentrations (2–10% w/w) to polymer gels and films as reinforcing agents. Significant changes in mechanical properties, especially maximum load and tensile strength, were obtained for fibrils derived from several cellulosic sources, including cotton, softwood, and bacterial cellulose. For extruded starch plastics, the addition of cotton-derived microfibrils at 10.3% (w/w) concentration increased Young’s modulus by 5-fold relative to a control sample with no cellulose reinforcement. Preliminary data suggests that shear alignment significantly improves tensile strength. Addition of microfibrils does not always change mechanical properties in a predictable direction. Whereas tensile strength and modulus were shown to increase during addition of microfibrils to an extruded starch thermoplastic and a cast latex film, these parameters decreased when microfibrils were added to a starch–pectin blend, implying that complex interactions are involved in the application of these reinforcing agents. 相似文献
11.
The increasing use of plastics in packaging materials leads to growing amounts of plastic waste. Recycling material is generally
regarded as advantageous. But in fact very few products are made from plastic waste, partly this can be explained by that
little is known about the recycling process and the properties of collected materials. There is a need for injection moulding
grades of recycled polyethylene, while large amounts of extrusion grades are available from packaging waste. A controlled
way of de-branching or partly degrading PE would be desirable. Peroxides are commonly used to crosslink polyolefins, but under
certain conditions a chain scission reaction occur. Another problem encountered with recycling of polyethylene are the poor
miscibility of low amounts contaminations, i. e. polypropylene. A compatibilizer can improve properties of such polymer blends,
in this work EPDM is used as compatibilzer. Studies of mechanical properties and viscosity measurements show that it is possible
to partly degrade PE with peroxide exposing it to high temperature and oxygen. The properties of PE/PP blends were improved
with EPDM as compatibilizer. 相似文献
12.
In this paper investigation on thermoplastic elastomers (TPE) and thermoplastic vulcanizates (TPV) derived from waste polypropylene
(WPP) of Municipal Solid Waste (MSW) and acrylonitrile-butadiene rubber (NBR) are reported. The WPP was segregated, cleaned,
dried and melt processed with NBR at 180 °C in a Brabender Plasticorder at different blend ratios. TPV was prepared by dynamic
vulcanization of the TPE with conventional sulfur accelerator curing system. The mechanical properties measured were found
to decrease with increase in NBR proportion in the blend; however the dynamic vulcanization of the nitrile rubber phase enhanced
the strength properties of the corresponding TPE. The crystallinity of the WPP reduced with increase in NBR ratio. The dynamic
modulus decreased with nitrile rubber content in the TPE. Interestingly, the storage modulus of the TPV at higher rubber content
enhanced significantly and damping characteristics increased sharply. The rheology studies reveal that the damping of the
blend has been reduced with the addition of high storage modulus rubber at melt processing conditions and hence increased
viscosity. The amorphous rubber content with higher storage modulus imparts higher viscosity for the polypropylene (PP) matrix
at the processing temperature. The SEM study reveals that the dynamic vulcanization of the rubber phase in the blend caused
a smoother and finer surface morphology. 相似文献
13.
Effectiveness of novel and traditional treatments on the performance of incinerator bottom ash waste
Management of natural aggregate resources has become one of the most important challenges in construction, especially for high demand applications such as roads. Incinerator bottom ash (IBA), which is produced from burning domestic waste, has been considered a useful solution to the shortage of natural resources. In this research, IBA was mixed with limestone to produce an acceptable blend for use as a road foundation layer. Novel and traditional additives were adopted to improve the mechanical properties of IBA blends. The study focused on the treatment effect of additives on the mechanical characteristics of IBA blends under monotonic and cyclic triaxial stresses. The investigation evaluated fundamental material properties, including resilient modulus, initial Young's modulus and Poisson's ratio. Two nonlinear empirical models were adopted to depict the experimental resilient modulus results of the IBA blends. An approach has been proposed to predict realistic and representative values of resilient modulus for the material. In addition, a new relationship has been established between Young's modulus, resilient modulus and Poisson's ratio. Triaxial test results revealed that additives are more efficient with the control limestone blend than with the IBA blends. Novel additives, such as enzyme I and silica fume, produced a noticeable improvement in IBA properties in comparison to traditional additives. 相似文献
14.
Jutarat Prachayawarakorn Pornnipa Ruttanabus Pimvilai Boonsom 《Journal of Polymers and the Environment》2011,19(1):274-282
Biodegradable polymer was prepared as thermoplastic starch (TPS) using rice and waxy rice starches. In order to increase mechanical
properties and reduce water absorption of the TPS, cotton fiber was incorporated as the fiber reinforcement into the TPS matrix.
The effect of cotton fiber contents and lengths on properties of the TPS was examined. Internal mixer and compression molding
machine were used to mix and shape the samples. It was found that the thermoplastic rice starch (TPRS) showed higher stress
at maximum load and Young’s modulus but lower strain at maximum load than the thermoplastic waxy rice starch (TPWRS). In addition,
stress at maximum load and Young’s modulus of both TPRS and TPWRS increased significantly with the addition of the cotton
fiber. Cotton fiber contents and lengths also affected mechanical properties of the TPRS and TPWRS composites. Moreover, water
absorption of the TPRS and TPWRS composites decreased by the use of the cotton fibers. FT-IR and XRD techniques were used
to study a change in functional group and crystallinity of the thermoplastic starch composites. Morphological, thermal and
biodegradable properties of different thermoplastic starch composites were also investigated. 相似文献
15.
Thermal and Mechanical Properties of Plastics Molded from Sodium Dodecyl Sulfate-Modified Soy Protein Isolates 总被引:3,自引:0,他引:3
Soybean protein is a potential material for manufacturing of biodegradable plastics. The objective of this investigation was to characterize the thermal and mechanical properties of plastics made from sodium dodecyl sulfate (SDS)-modified soy proteins. Soy protein isolate (SPI) was prepared from defatted soy flour, modified with various concentrations of SDS, and then molded into plastics. The temperatures of denaturation of the modified soy protein increased at low SDS concentration and then decreased at high SDS concentration. At the same SDS concentration, the plastics molded from the modified soy proteins showed a similar temperature of denaturation, but a lower enthalpy of denaturation compared to the modified soy protein. Young's modulus of the plastics decreased as SDS concentration increased, and the tensile strength and strain at break of the plastics reached a maximum value at 1% SDS modification. Two glass transition temperatures were identified corresponding to the 7S and 11S globulins in SPI by dynamic mechanical analysis, and they decreased as SDS concentration increased. The SDS modification increased the water absorption of the plastics. 相似文献
16.
Shouhai Li Chunpeng Wang Fuxiang Chu Jianling Xia Yuzhi Xu 《Journal of Polymers and the Environment》2013,21(4):1072-1082
Two dissimilar renewable resource-based thermoplastic acorn nutlet (TPAN) materials were prepared via twin-screw extrusion with the aid of glycerol or monoethanolamine as plasticizers, and then two TPAN/polycaprolactone (PCL) composites with different plasticized systems were prepared. Mechanical test showed that glycerol-based composites had excellent tensile properties, and at a PCL content of 50 wt%, their tensile strength and elongation at break reached 14.4 MPa and 1,361 %, respectively. The micro-morphologic investigation of liquid-nitrogen brittle fracture surface indicated certain interface adhesion between glycerol-based thermoplastic acorn nutlet (GTPAN) and PCL. Dynamic mechanical thermal analysis , differential scanning calorimetry and thermogravimetric analysis demonstrated that the weight ratios of TPAN in composites significantly affected the crystallinity, glass transition temperature (Tg), melting temperature (Tm) and thermal stability of composites. Soil burial degradation analysis displayed that all composites had excellent biodegradability. These results demonstrated that GTPAN/PCL composites had superior mechanical and biodegradable properties, enough to partially replace the conventional thermoplastic plastics. 相似文献
17.
Parisa Faibunchan Yeampon Nakaramontri Wannarat Chueangchayaphan Skulrat Pichaiyut Claudia Kummerlöwe Norbert Vennemann Charoen Nakason 《Journal of Polymers and the Environment》2018,26(7):2867-2880
Novel biodegradable thermoplastic elastomer based on epoxidized natural rubber (ENR) and poly(butylene succinate) (PBS) blend was prepared by a simple blend technique. Influence of blend ratios of ENR and PBS on morphological, mechanical, thermal and biodegradable properties were investigated. In addition, chemical interaction between ENR and PBS molecules was evaluated by means of the rheological properties and infrared spectroscopy. Furthermore, the phase inversion behavior of ENR/PBS blend was predicted by different empirical and semi-empirical models including Utracki, Paul and Barlow, Steinmann and Gergen models. It was found that the co-continuous phase morphology was observed in the blend with ENR/PBS about 58/42 wt% which is in good agreement with the model of Steinmann. This correlates well to morphological and mechanical properties together with degree of crystallinity of PBS in the blends. In addition, the biodegradability was characterized by soil burial test after 1, 3 and 9 months and found that the biodegradable ENR/PBS blends with optimum mechanical and biodegradability were successfully prepared. 相似文献
18.
Amnuay Wattanakornsiri Katavut Pachana Supranee Kaewpirom Matteo Traina Claudio Migliaresi 《Journal of Polymers and the Environment》2012,20(3):801-809
Green composites obtained from biodegradable renewable resources have gained much attention due to environmental problems resulting from conventionally synthetic plastics and a global increasing demand for alternatives to fossil resources. In this work we used different cellulose fibers from used office paper and newspaper as reinforcement for thermoplastic starch (TPS) in order to improve their poor mechanical, thermal and water resistance properties. These composites were prepared by using tapioca starch plasticized by glycerol (30 % wt/wt of glycerol to starch) as matrix reinforced by the extracted cellulose fibers with the contents ranging from 0 to 8 % (wt/wt of fibers to matrix). Properties of composites were determined by mechanical tensile tests, differential scanning calorimetry, thermogravimetric analysis, water absorption measurements, scanning electron microscopy, and soil burial tests. The results showed that the introduction of either office paper or newspaper cellulose fibers caused the improvement of tensile strength and elastic modulus, thermal stability, and water resistance for composites when compared to the non-reinforced TPS. Scanning electron microscopy showed a good adhesion between matrix and fibers. Moreover, the composites biological degraded completely after 8 weeks but required a longer time compared to the non-reinforced TPS. The results indicated that these green composites could be utilized as commodity plastics being strong, inexpensive, plentiful and recyclable. 相似文献
19.
Sridhar V Xiu ZZ Xu D Lee SH Kim JK Kang DJ Bang DS 《Waste management (New York, N.Y.)》2009,29(3):1058-1066
Novel thermoplastic composites made from two major industrial and consumer wastes, fly ash and waste tire powder, have been developed. The effect of increasing fly ash loadings on performance characteristics such as tensile strength, thermal, dynamic mechanical and magnetic properties has been investigated. The morphology of the blends shows that fly ash particles have more affinity and adhesion towards the rubbery phase when compared to the plastic phase. The fracture surface of the composites shows extensive debonding of fly ash particles. Thermal analysis of the composites shows a progressive increase in activation energy with increase in fly ash loadings. Additionally, morphological studies of the ash residue after 90% thermal degradation shows extensive changes occurring in both the polymer and filler phases. The processing ability of the thermoplastics has been carried out in a Monsanto processability testing machine as a function of shear rate and temperature. Shear thinning behavior, typical of particulate polymer systems, has been observed irrespective of the testing temperatures. Magnetic properties and percolation behavior of the composites have also been evaluated. 相似文献
20.
Bo Liu Jinwen Zhang Linshu Liu Arland T. Hotchkiss 《Journal of Polymers and the Environment》2011,19(3):559-567
Sugar beet pulp (SBP), the residue from sugar extraction, was compounded and turned into in situ thermoplastic composite materials.
The compounding was performed using a common twin- screw compounding extruder and water and glycerol were used as co-plasticizers.
The melt compounding of SBP utilized the water-soluble characteristics of pectin which is one of main components of SBP. The
structure of SBP was destroyed under extrusion and pectin was partially released and plasticized by water and glycerol. Scanning
electron microscopy revealed that the cellulose microfibrils were dispersed in the matrix of pectin and other ingredients.
Effects of the water and glycerol co-plasticizers on rheological, tensile and dynamic mechanical properties of the SBP plastics
were investigated. Effects of relative humidity of the environment on the tensile and dynamical mechanical properties of the
neat SBP compounds were also evaluated. The results demonstrated that SBP could be processed as a plastic with water and glycerol
as co-plasticizers using traditional processing equipments. 相似文献