共查询到20条相似文献,搜索用时 31 毫秒
1.
A. Ares R. Bouza S. G. Pardo M. J. Abad L. Barral 《Journal of Polymers and the Environment》2010,18(3):318-325
The aim of this paper was to investigate the effect of recycled polypropylene (PP) on the rheological, mechanical and thermal
properties of wood flour polypropylene composites. Beforehand, the influence of wood flour treated with a coupling agent on
the rheological behaviour had been looked at. By analysing moduli and viscosity curves and studying the thermal and mechanical
properties of samples with 10% filler it was possible to see that the recycled PP that was added change in either its physical
properties or its rheology. In the other wood plastic composites (WPC) studied, slight changes in the rheology behaviour were
observed. However, the same processing parameters may be used with and without recycled PP. Recycled PP is appropriate for
these kinds of composites to maintain the optimal rheological properties that make it easier to process the material by extrusion.
Furthermore, it is also possible to maintain the thermal and mechanical properties in comparison with the behaviour of virgin
PP/wood flour composites. 相似文献
2.
Saeed Kazemi Najafi Morteza Mostafazadeh-Marznaki Majid Chaharmahali 《Journal of Polymers and the Environment》2010,18(4):720-726
In this research, the influence of thermo-mechanical degradation of polypropylene (PP) on water absorption and thickness swelling
of beech wood flour–PP composites were studied. For this purpose, a virgin PP was thermo-mechanically degraded by two times
extrusion under controlled conditions. The results showed that the melt flow index, water absorption and thickness swelling
of PP significantly increase by extrusion and re-extrusion. The virgin PP and degraded polypropylene were compounded with
wood flour (at 60% by weight wood flour loading) in a counter-rotating twin-screw extruder in presence or absence of MAPP
to produce wood flour–PP composites. From the results, the composites containing recycled PP exhibited higher water absorption
and thickness swelling. The use of MAPP decreased water absorption and thickness swelling in composites made of virgin or
recycled PP. 相似文献
3.
Srivabut Chainarong Ratanawilai Thanate Hiziroglu Salim 《Journal of Material Cycles and Waste Management》2021,23(4):1503-1517
Journal of Material Cycles and Waste Management - An experimental mixture design was used to determine the optimum composition of wood–plastic composites (WPCs), manufactured from recycled... 相似文献
4.
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
5.
This study investigates the feasibility of using recycled high density polyethylene (rHDPE), polypropylene (rPP) and old newspaper (rONP) fiber to manufacture experimental composite panels. The panels were made through air-forming and hot press. The effects of the fiber and coupling agent concentration on tensile, flexural, internal bond properties and water absorption and thickness swelling of wood–fiber plastic composites were studied. The use of maleated polypropylene as coupling agent improved the compatibility between the fiber and both plastic matrices and mechanical properties of the resultant composites compared well with those of non-coupled ones. Based on the findings in this work, it appears that recycled materials can be used to manufacture value-added panels without having any significant adverse influence on board properties. It was also found that composites with rHDPE provided moderately superior properties, compared with rPP samples. 相似文献
6.
James S. Fabiyi Armando G. McDonald David McIlroy 《Journal of Polymers and the Environment》2009,17(1):34-48
The effects of weathering on the constituents of wood and polymer matrix behavior in wood plastic composites (WPCs) were investigated.
WPCs were produced from pine, extractives-free pine, and pine holocellulose fibers (60%) together with HDPE (40%). These composites
were subjected to xenon-arc accelerated and outside weathering for a total of 1200 h and 120 days, respectively. The color
and chemical changes that occurred on the surface of the WPCs were analyzed using a set of analytical techniques. For pine
and extractive-free pine filled composites, the results showed that the total color change, lightness, and oxidation increased,
while the lignin content decreased. In addition, the weight average molecular weight (Mw) and number average molecular weight (Mn) of extracted HDPE decreased with an increase in exposure time of the composites. However, HDPE crystallinity increased with
longer exposure time. Lightness of holocellulose-based WPC changed the least while the change in its HDPE crystallinity was
not significant compared to the other composite types. Therefore, holocellulose-based WPC may be preferred for applications
where color stability is of high priority. 相似文献
7.
This paper aims to evaluate the potential for the use of recycled expanded polystyrene and wood flour as materials for the development of wood plastic composites. The effects of wood flour loading and coupling agent addition on the mechanical properties and morphology of wood thermoplastic composites were examined. In addition, a methodology for the thermo-mechanical recycling of expanded polystyrene waste was developed. The results show that the mechanical properties decreased as the wood flour loading increased. On the other hand, the use of poly(styrene-co-maleic anhydride), SMA, as a coupling agent improved the compatibility between the wood flour and polystyrene matrix and the mechanical properties subsequently improved. A morphological study revealed the positive effect of the coupling agent on the interfacial bonding. The density values obtained for the composites were compared with the theoretical values and showed agreement with the rule of mixtures. Based on the findings of this work, it appears that both recycled materials can be used to manufacture composites with high mechanical properties and low density. 相似文献
8.
9.
Hajar Yousefian Kaouther Ben Azouz Denis Rodrigue 《Journal of Polymers and the Environment》2016,24(1):48-55
In the first part of this work, composites based on polypropylene (PP) and maple wood flour (MF) were prepared by melt compounding using twin-screw extrusion followed by compression molding. The morphological and mechanical properties of the composites were analyzed for three samples: PP, MF/PP and MF/PP containing maleic anhydride grafted polypropylene (MAPP) as coupling agent. The results showed that MF/PP composites have improved mechanical properties, especially tensile modulus (+33 %), with only 8 % increase in density. The addition of MAPP further improved the mechanical properties, in particular tensile modulus (up to 51 %), which could be related to better fiber/matrix adhesion. In the second step, nano crystalline cellulose (NCC) was added to all samples to produce NCC-MF/PP hybrid composites. From the mechanical analysis performed, the hybrid composites with MAPP have improved properties, especially tensile (+53 %) and flexural (+40 %) moduli. These results confirmed that multi-scale hybrid NCC-MF composites can substantially improve the mechanical properties of polyolefins with limited increase in density (14 %) leading to high specific properties. 相似文献
10.
Characterization of wood plastic composites made from landfill-derived plastic and sawdust: Volatile compounds and olfactometric analysis 总被引:1,自引:0,他引:1
Application of wood plastic composites (WPCs) obtained from recycled materials initially intended for landfill is usually limited by their composition, mainly focused on release of volatile organic compounds (VOCs) which could affect quality or human safety. The study of the VOCs released by a material is a requirement for new composite materials. Characterization and quantification of VOCs of several WPC produced with low density polyethylene (LDPE) and polyethylene/ethylene vinyl acetate (PE/EVA) films and sawdust were carried out, in each stage of production, by solid phase microextraction in headspace mode (HS-SPME) and gas chromatography–mass spectrometry (GC–MS). An odor profile was also obtained by HS-SPME and GC–MS coupled with olfactometry analysis. More than 140 compounds were observed in the raw materials and WPC samples. Some quantified compounds were considered WPC markers such as furfural, 2-methoxyphenol, N-methylphthalimide and 2,4-di-tert-butylphenol. Hexanoic acid, acetic acid, 2-methoxyphenol, acetylfuran, diacetyl, and aldehydes were the most important odorants. None of the VOCs were found to affect human safety for use of the WPC. 相似文献
11.
Effects of Waste Paper Sludge on the Physico-Mechanical Properties of High Density Polyethylene/Wood Flour Composites 总被引:1,自引:0,他引:1
Yahya Hamzeh Alireza Ashori Babak Mirzaei 《Journal of Polymers and the Environment》2011,19(1):120-124
The objective of this work was to determine some physical and mechanical properties of the high density polyethylene (HDPE)
composites reinforced with various mixtures of the paper sludge and the wood flour, and to evaluate the coupling agent performance.
The waste sludge materials originating from two different sources including paper making waste water treatment sludge (PS)
and ink-eliminated sludge (IES) were characterized in terms of physico-chemical properties. In the experiment, four levels
of paper sludge (20, 30, 40 and 60 wt%), three levels of wood flour (20, 40 and 60 wt%), and two levels of coupling agent
(MAPE) content (2 and 3 wt%) were used. The flexural properties of the composites were positively affected by the addition
of the sludge. Especially, tensile modulus improved with the increase of paper sludge content. With the addition of MAPE,
flexural properties improved considerably compared with control specimens (without any coupling agent). The results showed
that the water absorption (WA) and thickness swelling (TS) values of the samples decreased considerably with increasing sludge
content in the composite, while they increased with increasing wood flour content. It is to be noted that with incorporation
of MAPE in the composite formulation, the compatibility between the wood flour and HDPE was enhanced through esterification,
which reduced the WA and TS and improved the mechanical properties. Composites made with IES exhibited superior physico-mechanical
properties compared with the PS filled composites. Overall results suggest that the waste paper sludge materials were capable
of serving as feasible reinforcing fillers for thermoplastic polymer composites. 相似文献
12.
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
13.
Recycled Natural Fiber Polypropylene Composites: Water Absorption/Desorption Kinetics and Dimensional Stability 总被引:1,自引:0,他引:1
Detailed analysis of the effects of recycling process on long-term water absorption, thickness swelling and water desorption
behavior of natural fiber polypropylene composites is reported. Composite materials containing polypropylene and wood flour,
rice hulls or bagasse fibers were produced at constant fiber loading and were exposed to a simulated recycling process consisting
of up to five times grinding and reprocessing under controlled conditions. A wide range of analytical methods including water
absorption/desorption tests, thickness swelling tests, density measurement, scanning electron microscopy, image analysis,
contact angle, fiber length analysis and Fourier transform infrared spectroscopy was employed to understand the hygroscopic
behavior of the recycled composites. Water absorption and thickness swelling behaviors were modeled using existing predictive
models. Results indicated that generally the recycled composites had considerably lower water absorption and thickness swellings
as compared with the original composites which were attributed to changes in physical and chemical properties of the composites
induced by the recycling process. 相似文献
14.
This study is conducted to look at the modification of mechanical properties of recycled polypropylene (PP) from post-consumer containers with the addition of stabilizers, elastomer (ethylene-octene rubber, EOR) and calcium carbonate (CaCO(3)). The mechanical and thermal properties of the blends were evaluated. The results showed limited changes with the addition of elastomer and calcium carbonate on the mechanical properties of the recycled polypropylene. Some differences were observed, but the trends were not reproducible over the different compositions. DSC analysis confirmed the presence of polyethylene (PE) in the recycled polypropylene. The polyethylene impurity and the presence of many different qualities of polypropylene in the recycled material may have prevented any possible improvement in the mechanical properties by the addition of EOR and CaCO(3), improvements seen in previous studies on virgin polypropylene. The compatibility of the different homopolymers and copolymers of PP used in consumer packaging is not known, while polyethylene and polypropylene are known not to be miscible with each other. The mixture of qualities and materials may explain such a poor blending. Reusing and upgrading of recycled PP from post-consumer containers would therefore first require a better sorting of the post-consumer waste. The use of an adequate compatibilizer that would allow a uniform and homogeneous blending of the raw material mixture might enhance the mechanical properties. 相似文献
15.
Rheological Investigation of Wood-Polypropylene Composites in Rotational Plate Rheometer 总被引:1,自引:0,他引:1
Ehsan Soury Amir Hossein Behravesh Ghaus M. Rizvi Nathan Jafarian Jam 《Journal of Polymers and the Environment》2012,20(4):998-1006
In this research work, the rheological properties of Wood-Plastic Composites (WPC) with some selected compositions are investigated. WPC is being recognized as a green composite that, in the past 20?years, has emerged to a commercial product. A study on rheological properties of these materials can give insight into the proper selection of composition and processing condition. Two grades of polypropylene (PP) with two different melt flow indexes (MFI) were selected to prepare WPCs with three different wood contents (50, 60 and 70?% wt.). Four types of rheological experiments were performed utilizing a rotational plate rheometer: (1) strain sweep, (2) frequency sweep, (3) temperature sweep and (4) steady shear rate sweep. The independent variables were chosen as wood content, MFI of polymer (two types), melt temperature, frequency or shear rate, the gap between the plates, and strain percentage. The strain sweep tests specified the linear and non-linear viscoelastic zones of each experiment. The results of frequency sweep experiments indicated that increasing the wood content and frequency and also decreasing the strain percentage and the gap distance, lead to an increase in the storage modulus. Regarding the loss modulus, wood percentage and the gap distance presented positive effects and strain percentage showed a negative effect. The behavior of complex viscosity was almost similar to that of the storage modulus but increasing the frequency caused a decrease in the complex viscosity. In case of temperature sweep experiments, it was observed that the rheological properties exhibit a rapid change near to a temperature of 160?°C. The results also showed that beyond this point, increasing the wood content and also MFI of polypropylene caused an increase in the storage modulus. The results of steady shear rate sweep experiments specified that increasing wood content and also decreasing the MFI of PP, the gap distance and shear rate lead to an increase in both viscosity and shear stress. 相似文献
16.
Novel lightweight composite foams based on recycled polypropylene reinforced with cellulosic fibres obtained from agricultural residues were prepared and characterized. These composites, initially prepared by melt-mixing recycled polypropylene with variable fibre concentrations (10-25 wt.%), were foamed by high-pressure CO2 dissolution, a clean process which avoids the use of chemical blowing agents. With the aim of studying the influence of the fibre characteristics on the resultant foams, two chemical treatments were applied to the barley straw in order to increase the α-cellulose content of the fibres. The chemical composition, morphology and thermal stability of the fibres and composites were analyzed. Results indicate that fibre chemical treatment and later foaming of the composites resulted in foams with characteristic closed-cell microcellular structures, their specific storage modulus significantly increasing due to the higher stiffness of the fibres. The addition of the fibres also resulted in an increase in the glass transition temperature of PP in both the solid composites and more significantly in the foams. 相似文献
17.
M. Masud K. Khan Carlos J. Hilado Sushant Agarwal Rakesh K. Gupta 《Journal of Polymers and the Environment》2007,15(3):188-194
Acrylonitrile–Butadiene–Styrene (ABS), Polycarbonate (PC) and their alloys are widely used in automotive industry, computer
and equipment housings. With increasing disposal of end-of-life electronic equipment, there is also an increased demand for
recycling of these materials so that they do not pose environmental challenge as solid waste. One of the recycling approaches
is mechanical recycling of these thermoplastics where recycled plastic is melt blended with virgin materials to obtain a high
quality product. Besides obtaining desirable mechanical properties, such blends should also conform to fire safety standards.
In this work, a series of blends were prepared using PC and ABS recovered from discarded computers and virgin materials using
a twin-screw extruder. Their flammability properties were evaluated using burner flammability tests and Ohio State University
(OSU) release rate tests. It was found that the extinguishing time, burning extent and weight loss appears to progressively
decrease with the addition of both virgin or recycled PC to virgin or recycled ABS. It was also seen that the addition of
the 70% of PC, virgin or recycled, to ABS virgin or recycled, appears to significantly decrease heat release and smoke evolution.
The results of this study indicate that recycled polycarbonate can be used as an additive for virgin or recycled ABS, as a
means of giving flame resistance to ABS in high-value applications. This result is significant when related to the result
obtained by a separate study indicating that up to 25% of recycled material can be used without degradation of mechanical
properties in the presence of 15% short glass fiber reinforcement. 相似文献
18.
Amir Nourbakhsh Abdollah Hosseinzadeh Farshid Basiji 《Journal of Polymers and the Environment》2011,19(4):908-911
The study was carried out to investigate the effects of filler content and two different compatibilizing agents (Eastman G-3003
and G-3216) on the mechanical properties of polypropylene reinforced with corn stalk and wood flour. In the sample preparation,
three levels of filler loading (30, 40 and 50 wt%) and one level of compatibilizing agent content (2.5 wt%) were used. For
overall trend, with addition of both grades of the compatibilizing agents, tensile and flexural properties of the composites
significantly improved, as compared with the pure PP. Tensile and flexural properties reach a maximum at 40 wt% filler content
and gradually decrease with a further increase in wood particle content. The composites treated with G-3003 gave better results
in comparison with G-3216. This could be caused by the high melt viscosity of G-3003. In general, corn stalk flour filled
composites showed superior mechanical properties. 相似文献
19.
Fabian Knappich Martin Schlummer Andreas Mäurer Harald Prestel 《Journal of Material Cycles and Waste Management》2018,20(3):1541-1552
Galvanized or “chromium-plated” plastics are well known to the consumer from the automotive sector and sanitary area. Polymers such as acrylonitrile butadiene styrene (ABS) are typically coated with a layer system of chromium, nickel and copper to obtain the characteristic optical surface and resistance properties. Due to the complex manufacturing process and high quality requirements, the production of these plastic metal composites generates 10–30% of rejects. We, therefore, developed an innovative process cascade for the recovery of both components (metal and polymer) applying established technologies (mechanical pre-treatment, classification, melt filtration, CreaSolv® Process) and were able to obtain ABS regranulate having excellent properties regarding the characteristic values for strength but slight compromises in impact characteristics. Blends with different amounts of virgin ABS, virgin PC and recycled ABS material as well as the pure cases were successfully re-metallized, all of them passing adhesion test, thermal shock resistance and CASS test. The high purity of the recovered materials led to increased redemption prices for metal and polymer by a factor of 6 and 2.5, respectively. Thus, the value added of metallized plastic waste is maximized, revealing a highly positive economic prognosis of a commercial implementation of the developed process—even at moderate scale. 相似文献
20.
This study investigated weathering effects on polyvinyl chloride (PVC) based wood plastic composites (WPC), with a focus on
the color and structure that is attributed to the material composition. It is directed towards quantifying the main chemical
modifications, such as carbonyl and vinyl groups which are formed during weathering. These composites were subjected to three
weathering regimes: exterior, accelerated xenon-arc, and accelerated UVA. The change in color was monitored using colorimetry.
Fourier transform infrared spectroscopy was used to identify and quantify the chemical modifications (carbonyl formation and
vinyl propagation) due to weathering. Additionally, scanning electron microscopy was employed to observe the physical morphological
changes that occurred. The results showed that exterior and accelerated xenon-arc and UVA weathering regimes increased the
degree of lightness, total color change, carbonyl concentration, and wood loss on the surfaces of the weathered composites.
The increased carbonyl concentration during weathering implied that degradation had occurred by oxidation process. Also, oxidation
and lignin (from the wood) degradation influenced the color (lightness) of PVC based WPC upon weathering. 相似文献