共查询到20条相似文献,搜索用时 31 毫秒
1.
P. Noorunnisa Khanam H. P. S. Abdul Khalil G. Ramachandra Reddy S. Venkata Naidu 《Journal of Polymers and the Environment》2011,19(1):115-119
In this study, effect of fibre surface treatment on tensile, flexural and chemical resistance properties were studied for
sisal fibre reinforced composites. Natural ligno cellulosic sisal fibre reinforced composites were prepared by different surface
treatments by hand lay-up method. Fibre surface treatments were carried out to produce good interface between the fibre and
the matrix to improve the mechanical properties. Fibre surface treatments were done by boiled the sisal fibres in different
% of NaOH and treated the fibres in different % of NaOH, treated in acetic acid and methanol. Unsaturated polyester resin
was used as the matrix for preparing the composites. For comparison, these properties for untreated sisal fibre reinforced
composites were also studied. From the results it was observed that 18% aqueous NaOH boiled sisal fibre reinforced composites
have higher tensile, flexural properties than other composites. Untreated sisal fibre composites show lower properties than
treated composites. Chemical resistance properties indicate that all sisal fibre reinforced composites are resistance to all
chemicals except carbon tetra chloride. The tests are carried out as per the ASTM standards. 相似文献
2.
Alireza Ashori 《Journal of Polymers and the Environment》2010,18(1):65-70
Hybrid composites of thermoplastic biofiber reinforced with waste newspaper fiber (NF) and poplar wood flour (WF) were prepared.
The weight ratio of the lignocellulosic materials to polymer was 30:70 (w:w). Polypropylene (PP) and maleic anhydride grafted
polypropylene (MAPP) were also used as the polymer matrix and coupling agent, respectively. The mechanical properties, morphology
and thermal properties were investigated. The obtained results showed that tensile and flexural modulus of the composites
were significantly enhanced with addition of biofibers in both types (fiber and flour), as compared with pure PP. However,
the increasing in WF content substantially reduced the tensile, flexural and impact modulus, but improved the thermal stability.
This effect is explained by variations in fiber morphological properties and thermal degradation. Increasing fiber aspect
ratio improved mechanical properties. The effect of fiber size on impact was minimal compared to the effects of fiber content.
Scanning electron microscopy has shown that the composite, with coupling agent, promotes better fiber–matrix interaction.
The largest improvement on the thermal stability of hybrid composites was achieved when WF was added more. In all cases, the
degradation temperatures shifted to higher values after addition of MAPP. This work clearly showed that biofiber materials
in both forms of fiber and flour could be effectively used as reinforcing elements in thermoplastic PP matrix. 相似文献
3.
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
4.
This paper mainly focuses on the fabrication process of long fibre reinforced unidirectional thermoplastic composites made using both natural (untreated) treated jute yarns. Jute yarns were wound in layers onto a metallic frame. Polypropylene films were inserted between these layers and compression moulded to fabricate unidirectional jute/PP composite specimens. Static mechanical properties were evaluated from tensile three point bending tests. Pre- post-failure examination were carried out on the test specimens using optical scanning electron microscopy to analyse the test results and investigate the correlations between their impregnation state, processing conditions, mechanical performances and fracture morphologies. For the unidirectional jute/PP film-stacked composites, the results indicated that the processing condition at the moulding temperature of 160°C and moulding pressure of 2.0 MPa for 15 min was ideally suited to obtain optimized properties. Improved wettability of resin melts due to complete matrix fusion at this processing condition facilitated thorough impregnation with minimum microstructural imperfections (microvoids) being generated. Jute/PP composites that contained treated jute yarns have shown superiority in tensile bending properties. Jute yarns polished or coated with PVA/PP (polyvinyl alcohol/polypropylene) must have contributed positively to fibre/matrix interfacial interactions leading to matrix to fibre effective stress transfer, thereby improving their reinforcing effects. Tensile strength and modulus of PP resin increased by approximately 285% and 388%, respectively, due to 50 wt% reinforcement by natural jute yarns. Further improvements in strength and modulus were achieved by approximately 14% and 10%, respectively, when treated yarns were used . The maximum bending stress modulus of jute/PP composites containing untreated yarns were approximately 190% and 460% higher than those of the virgin PP materials, and bending properties were improved by further 11% and 23%, respectively, due to coating treatments on the yarn surface. 相似文献
5.
F. Sarasini D. Puglia E. Fortunati J. M. Kenny C. Santulli 《Journal of Polymers and the Environment》2013,21(3):881-891
In the present study, Phormium Tenax fiber reinforced PLA composites were processed by injection molding and twin screw compounding with a fiber content ranging from 10 to 30 wt%. Three surface treatment methods have been used to improve the Phormium Tenax fiber-matrix interfacial bonding that are as follows: (1) aqueous alkaline solution, (2) silane coupling agent, and (3) a combination of alkaline and silane treatment. The mechanical, thermal and morphological properties of the resulting composites were investigated. The results have shown that the moduli of surface treated fiber reinforced composites are lower than the ones obtained for untreated composites (as a consequence of the decrease in fiber modulus caused by the chemical treatments) and no significant increase in strength was observed for any of the composites compared to neat PLA. SEM micrographs of composite fractured surfaces confirmed an improvement in the interfacial strength, which was insufficient nonetheless to significantly enhance the mechanical behavior of the resulting composites. Results from thermogravimetric analysis and differential scanning calorimetry suggest that surface treatment of Phormium affects the ability of PLA to cold crystallize, and the thermal stability of the composites at the different fiber contents was reduced with introduction of alkali and silane treated Phormium fibers. 相似文献
6.
Maria T. B. Pimenta Antonio J. F. Carvalho Fabiola Vilaseca Jordi Girones Joan P. López Pere Mutjé Antonio A. S. Curvelo 《Journal of Polymers and the Environment》2008,16(1):35-39
Treated sisal fibers were used as reinforcement of polypropylene (PP) composites, with maleic anhydride-grafted PP (MAPP)
as coupling agent. The composites were made by melting processing of PP with the fiber in a heated roller followed by multiple
extrusions in a single-screw extruder. Injection molded specimens were produced for the characterization of the material.
In order to improve the adhesion between fiber and matrix and to eliminate odorous substances, sisal fibers were treated with
boiling water and with NaOH solutions at 3 and 10 wt.%. The mechanical properties of the composites were assessed by tensile,
bend and impact tests. Additionally, the morphology of the composites and the adhesion at he fiber–matrix interface were analyzed
by SEM. The fiber treatment led to very light and odorless materials, with yields of 95, 74 and 62 wt.% for treatments with
hot water, 3 and 10 wt.% soda solution respectively. Fiber treatment caused an appreciable change in fiber characteristics,
yet the mechanical properties under tensile and flexural tests were not influenced by that treatment. Only the impact strength
increased in the composites with alkali-treated sisal fibers. 相似文献
7.
Environmentally friendly composite materials can be prepared using wood fibers and/or various types of agro-derived fibers as reinforcements. In this study, agro-residues such as wheat straw and corn stem filled polypropylene were prepared and their suitability was investigated as a reinforcing filler in thermoplastics and as an alternative to the wood flour filled plastics. Effect of compounding techniques, compatibilizer and fungal treatment of agro-residues on the mechanical properties of the composites were evaluated. It was found that high shear compounding of wheat straw fibers exhibited similar properties to that produced by the milled wheat straw. This may be due to the extensive fiber breakage occurred during the high shear compounding that results in a similar aspect ratio to that of milled straw. Compatibilizer is needed for improving the strength properties of the agro-residue filled PP composites. Fungal treatment of milled wheat straw did not show much improvement in the strength properties of the composites. Comparison of mechanical properties of the agro-residue filled PP with that of the wood flour and the old newsprint filled PP showed the suitability of the agro-residues as alternative filler for thermoplastics. 相似文献
8.
Shouhai Li Chunpeng Wang Xiaowei Zhuang Yong Hu Fuxiang Chu 《Journal of Polymers and the Environment》2011,19(1):301-311
Renewable resource-based composites were prepared with acorn powder and Thermoplastic resin poly(lactic acid) (PLA) by twin-screw
extrusion followed by injection molding processing or hot-compression molding processing. The study of the composites microstructure
showed poor adhesion between acorn powder and PLA matrix. The hygroscopicity, mechanical properties and melt flow property
of composites were promising even though the composites had a 70 wt% content of acorn powder. Silane coupling agent, 4,4′-Methylenebis
(phenyl isocyanate) and PLA grafted with maleic anhydride did not show obvious effect on mechanical properties of composites.
The impact resistance strength of reinforced composites with steel fiber webs were improved greatly in comparison with those
having no steel fiber webs. Thermal properties results of DSC and DMA showed that the presence of acorn powder significantly
affected the crystallinity, crystallization temperature (Tc), glass transition temperature (Tg) and melting temperature (Tm) of PLA matrix. The study results proved that composites had superior mechanical properties, enough to partially replace
the conventional thermoplastic plastics. 相似文献
9.
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
10.
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
11.
Environmentally friendly green composites were prepared by blending Wheat gluten (WG) as matrix, dialdehyde starch (DAS) as
filler and glycerol as plasticizer followed by compression molding of the mixture at 110 °C. The properties of the WG/DAS
composite are compared with those of the WG/native wheat starch (NWS) composites. While tensile strength and strain at break
decrease with increasing NWS content in the WG/NWS composites, a small content of DAS could improve tensile strength and strain
at break simultaneously in the WG/DAS composites. The WG/DAS composites exhibit reduced moisture absorption in comparison
with the WG/NEW composites. Formation of chemical bonding between DAS and WG is beneficial for the dispersion of DAS in the
WG matrix and WG/DAS composites exhibit improved mechanical properties and reduced moisture absorption over the WG/NWS composites. 相似文献
12.
Divia P. Sreenivasan A. Sujith C. Rajesh 《Journal of Polymers and the Environment》2018,26(7):2720-2729
Biocomposites of acrylonitrile butadiene rubber (NBR) reinforced with chicken feather fibre (CF) were prepared using dicumyl peroxide (DCP) as vulcanizing agent. Composites with three series of chicken feather fibres were studied i.e., raw (RCF), sterilized (SCF) and alkali treated (ACF). The cure characteristics of composites were studied. The mechanical properties of NBR were found to be improved by the incorporation of chicken feather fibre in all forms. Surface modification of the fibre was done by alkaline treatment to improve the interfacial adhesion and it characterised by FTIR. Better properties are shown by the composites with ACF. The swelling behaviour of the composites in N,N-dimethylformamide, acetonitrile, dimethyl sulfoxide and water were analyzed for the swelling coefficient values. The biodegradable characteristics of CF reinforced NBR composites were studied by soil burial test which indicated that it is an eco-friendly and acceptable material. Scanning electron microscopy studies support the results of mechanical properties. The outcome obtained from this study is believed to assist the development of environmentally–friendly composites especially for specific product applications like oil seals, hoses and automobile bushes etc. 相似文献
13.
Growing interest in green products has provided fresh impetus to the research in the field of renewable materials. Plant fibers are not only renewable but also light in weight and low in cost. Polymer composites manufactured using them find applications in diverse fields such as automobiles, housing, and furniture. However, their hydrophilic nature and inadequate adhesion with matrix limits their use in high performance applications. In this study, a novel method for improving adhesion characteristics of natural fibers has been developed. This method is carried out by treating hemp fibers with a fungus: Ophiostoma ulmi, obtained from elm tree infected with Dutch elm disease. Treated fibers showed improved acid–base characteristics and resistance to moisture. Improved acid–base interactions between fiber and resin are expected to improve the interfacial adhesion, whereas improved moisture resistance would benefit the durability of the composites. Finally, composites were prepared using untreated/treated fibers and unsaturated polyester resin. Composites with treated fibers showed slightly better mechanical properties, which is most probably due to improved interfacial adhesion. 相似文献
14.
Hamid Essabir Souad Nekhlaoui Mohammed Ouadi Bensalah Denis Rodrigue Rachid Bouhfid Abou el kacem Qaiss 《Journal of Polymers and the Environment》2017,25(3):658-666
The industrial production of wet phosphoric acid in Morocco led to controversial stockpiling of waste phosphogypsum by-products resulting in the release of significant amounts of toxic impurities in salt marshes. In the framework of fighting against global climate change and efforts to reduce toxic industrial wastes (phosphate industry), this work presents a new polymer composite based on phosphogypsum (PhG) and polypropylene (PP).The compounds were produced by twin-screw extrusion and injection molding. The morphological results show that good affinity between PhG and PP led to good particle dispersion/distribution in the polymer matrix. Thermal characterizations showed that PhG particles improved the thermal stability of PP with a 50 °C increase at 40 wt%. The optimum tensile modulus was also obtained at 40 wt% with a 74 % increase over neat PP. Dynamical mechanical analysis showed that PhG addition can improve the viscoelastic properties of PP for potential applications under dynamic stress. Overall, it can be concluded that PhG is potential reinforcing filler for the production of PP composites and represents a promising avenue for the valorization of this waste as a new raw material while resolving some environmental issues. 相似文献
15.
Justin R. Barone 《Journal of Polymers and the Environment》2009,17(2):143-151
Short fiber reinforced polymer composites were prepared from lignocellulose fibers and feather keratin polymer (FKP). The
FKP matrix was prepared from the reactive processing of poultry feather keratin, glycerol, water, and sodium sulfite. Lignocellulose
fibers of varying source, length, and mass fraction were used and it was found that positive reinforcement of FKP was affected
by all three. Positive reinforcement was defined as an increase in elastic modulus when normalized by FKP with the same amount
of glycerol but no fibers. Positive reinforcement was only able to occur for modulus but not stress at break indicating that
the composites were of high physical properties only under small deformations. At large deformations, fiber pull-out was observed
in the composites using scanning electron microscopy. The most likely origin of this behavior appeared to be from weak fiber–polymer
interactions dominated by friction and rationalized by a force balance across the fiber–polymer interface. High fiber loadings
were shown to be reinforcing because of the formation of a network of lignocellulose fibers. The addition of lignocellulose
fibers increased the thermal stability of the material. 相似文献
16.
Iuliana Spiridon Carmen-Alice Teacă Ruxanda Bodîrlău Maria Bercea 《Journal of Polymers and the Environment》2013,21(2):431-440
Tartaric acid modified starch microparticles (TA-SM) previously obtained using the dry preparation technique were introduced as filler within glycerol plasticized-corn starch (GCS), the composites being prepared by casting process. The effects of cellulose addition within the TA-SM-GCS matrix on the structure, surface properties and water sorption, as well as mechanical and thermal properties of starch-based composite films were investigated. The water resistance and thermal stability were slightly improved through addition of high content of cellulose due to the inter-component H-bonding between components. The evaluation of mechanical properties evidenced a significant increase of the tensile strength of the composites with increasing the content level of cellulose. 相似文献
17.
Adriana Gregorova Vladimir Sedlarik Miroslav Pastorek Hari Jachandra Franz Stelzer 《Journal of Polymers and the Environment》2011,19(2):372-381
This article contains a concept of the mechanical properties improvement of the highly crystalline poly(lactic acid) (PLA)
and filled composites. PLA as a semi-crystalline thermoplastic polymer was plasticized with poly(ethylene glycol) and filled
with 30 vol% of organic and/or inorganic filler. The degree of crytallinity was intentionally increased by annealing. The
filler/polymer matrix interphase was modified with the addition of 4, 4′-Methylenediphenyl diisocyanate (MDI). The effect
of compatibilizing as well as plasticizing agent on the thermal and mechanical properties, the water-absorption behaviour
and crystallization characteristics were studied. The results indicated that high content of filler and crystallites have
a strong influence on the composite′s mechanical properties despite of the plasticizer content, showing a high Young modulus.
The MDI seems to react in preference easy with plasticizing agent and then alternatively with filler due to the low functionality
of commercial PLA grade. 相似文献
18.
P. Noorunnisa Khanam H. P. S. Abdul Khalil M. Jawaid G. Ramachandra Reddy C. Surya Narayana S. Venkata Naidu 《Journal of Polymers and the Environment》2010,18(4):727-733
The variation of mechanical properties such as tensile and flexural properties of randomly oriented unsaturated polyester
based sisal/carbon fibre reinforced hybrid composites with different fibre weight ratios have been studied. The chemical resistance
test of these hybrid composites to various solvents, acids and alkalies were studied. The effect of NaOH treatment of sisal
fibres on the tensile, flexural and chemical resistance properties of these sisal/carbon hybrid composites has also been studied.
The hybrid composites showed an increase in tensile and flexural properties with increase in the carbon fibre loading. The
tensile properties and flexural properties of these hybrid composites have been found to be higher than that of the matrix.
Significant improvement in tensile properties and flexural properties of the sisal/carbon hybrid composites has been observed
by alkali treatment. The chemical resistance test results showed that these untreated and alkali treated hybrid composites
are résistance to all chemicals except carbon tetra chloride. Hand lay-up technique was used for making the composites and
tests are carried out by using ASTM methods. 相似文献
19.
Preparation, Thermal Properties and Thermal Reliability of Form-Stable Paraffin/Polypropylene Composite for Thermal Energy Storage 总被引:1,自引:0,他引:1
This study is focused on the preparation, characterization, and determination of thermal properties and thermal reliability
of paraffin/polypropylene (PP) composite as a novel form-stable phase change material (PCM) for thermal energy storage applications.
In the composite, paraffin acts as a PCM when PP is operated as supporting material. The composites prepared at different
mass fractions of paraffin (50, 60, 70, 80, and 90 w/w%) by solution casting method were subjected to leakage test by heating
the composites over the melting temperature of the PCM. The paraffin/PP composite (70/30 w/w%) is found as the maximum paraffin
containing composite and was characterized using Fourier transform infrared spectroscopy, optic microscopy, differential scanning
calorimetry (DSC), and thermal gravimetric analysis (TGA) techniques. DSC analysis indicated that the form-stable paraffin/PP
composite melts at 44.77–45.52 °C and crystallizes at 53.55–54.80 °C. It has latent heats of 136.16 and −136.59 J/g for melting
and crystallization, respectively. These thermal properties make it potential PCM for latent heat thermal energy storage (LHTES)
purposes such as solar space heating applications. Accelerated thermal cycling tests indicated that the form-stable PCM had
good thermal reliability. TGA also showed that the form-stable PCM degrades in two distinguishable steps and had good chemical
stability. 相似文献
20.
M. Barczewski D. Matykiewicz A. Krygier J. Andrzejewski K. Skórczewska 《Journal of Material Cycles and Waste Management》2018,20(2):914-924
The aim of this study was to determine thermal and mechanical properties and applicability of ground chestnut shell waste as a filler for poly(lactic acid) composites. The used amount of filler was ranging from 2.5 to 30 wt%. Spectroscopic analysis of composites and its ingredients was conducted by means of FT-IR method. The mechanical and thermal properties of the composites were determined in the course of static tensile test, Dynstat impact strength test, DMTA analysis, and DSC method. The fractured surface morphology of biocomposites was evaluated by SEM analysis. Incorporation of the filler influenced the overall mechanical properties of the composites characterized by high stiffness and lowered impact resistance. Fabricated composites with different amounts of non-reactive natural waste filler exhibited acceptable mechanical and thermal properties. Therefore, these composites can be used as eco-friendly, biodegradable materials for low-demanding applications. 相似文献