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1.
The rapid growth of environmentally sustainable and eco-friendly materials tends to the utilization of biowastes as filler in polymer matrix composites. The particulate composite with improved wettability of fillers and advanced approach can evolve polymer composites that exhibit promising applications in packaging, automobile, marine, construction, and aerospace. In the present work, one of the biowaste fillers were synthesized from Limonia acidissima shells via a top-down approach (pulverizing) and the surfaces were chemically modified using sodium hydroxide (NaOH) before they were used as fillers in vinyl ester polymer composites by different weight percentage (0, 5, 10, 15, and 20 wt%). The prepared particulate composites were characterized by mechanical properties, moisture absorption behavior, and morphology. At different filler loading the tensile strength, tensile modulus, flexural strength, flexural modulus, impact strength, hardness, density, and moisture intake tests were performed. The results reveal that the properties increased for composites filled with alkaline treated fillers for the same filler loading and found to be higher at filler loading of 15 wt%. The morphological analysis confirms the better interfacial bonding between alkali-treated particles and matrix due to the removal of non-cellulose materials from the surface of the particles.  相似文献   

2.
A potential application for conductive resins is in bipolar plates for use in fuel cells. The addition of carbon filler can increase the electrical and thermal conductivities of the polymer matrix but will also have an effect on the tensile and flexural properties, important for bipolar plates. In this research, three different types of carbon (carbon black, synthetic graphite, and carbon nanotubes) were added to polypropylene and the effects of these single fillers on the flexural and tensile properties were measured. All three carbon fillers caused an increase in the tensile and flexural modulus of the composite. The ultimate tensile and flexural strengths decreased with the addition of carbon black and synthetic graphite, but increased for carbon nanotubes/polypropylene composites due to the difference in the aspect ratio of this filler compared to carbon black and synthetic graphite. Finally, it was found that the Nielsen model gave the best prediction of the tensile modulus for the polypropylene based composites. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   

3.
One emerging market for thermally and electrically conductive resins is bipolar plates for use in fuel cells. Adding carbon fillers to thermoplastic resins increases the composite thermal and electrical conductivity. These fillers have an effect on the composite tensile and flexural properties, which are also important for bipolar plates. In this study, various amounts of three different types of carbon (carbon black, synthetic graphite particles, and carbon fibers) were added to Vectra A950RX liquid‐crystal polymer. In addition, composites containing combinations of fillers were also investigated via a factorial design. The tensile and flexural properties of the resulting composites were then measured. The objective of this study was to determine the effects and interactions of each filler with respect to the tensile and flexural properties. The addition of carbon black caused the tensile and flexural properties to decrease. Adding synthetic graphite particles caused the tensile and flexural modulus to increase. The addition of carbon fiber caused the tensile and flexural modulus and ultimate flexural strength to increase. In many cases, combining two different fillers caused a statistically significant effect on composite tensile and flexural properties at the 95% confidence level. For example, when 40 wt % synthetic graphite particles and 4 wt % carbon black were combined, the composite ultimate tensile and flexural strength increased more than what would be expected from the individual additive effect of each single filler. It is possible that linkages were formed between the carbon black and synthetic graphite particles that resulted in improved ultimate tensile and flexural strength. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008  相似文献   

4.
An investigation on the effect of filler geometry/shape on the dynamic mechanical properties of polymers was conducted. The viscoelastic damping matrix chosen was SBR and the fillers chosen were graphite, aramid, and carbon short fibers. The study was conducted by taking a control base compound of 20 parts N330 carbon black‐filled styrene butadiene rubber (SBR). Dynamic mechanical thermal analyzer was used to investigate the viscoelastic damping of the rubber composites at low dynamic strain levels. Compressive hysterisis at moderate degree of strain were evaluated for all the composite samples to probe into their high strain static damping properties. SEM was used to investigate the matrix‐fiber interaction and distribution of the fillers. Investigations demonstrated that the matrix‐filler interface plays a major role in energy dissipation. The amount of interface was analyzed by considering the half height width of tan δ peak. Fiber matrix interaction parameter was calculated from the tan δmax values for matrix and composite. It was observed the interaction parameter and the low strain tensile stress values register similar trend. Aramid short fibers were most effective in more energy dissipation than other fillers under consideration. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009  相似文献   

5.
Electrical and magnetic properties of composite materials prepared by incorporating various nickel-based fillers of different shapes into polyethylene were investigated. The fillers used were nickel powders, nickel filamentary powders, nickel flakes, and nickel-coated graphite fibers. The particle-size distributions of the fillers were determined both before and after the processing of the composite samples. A wide range of filler volume fractions were used. In some cases, the volume fraction approached the maximum packing fraction of the solid phase to significantly exceed the percolation threshold. The composite samples were characterized in terms of their volume resistivity, dielectric constant, and magnetic permeability values. Filler particles of asymmetric shapes were very effective in terms of altering the electrical properties of the composite samples. At the highest loading levels of the nickel fillers, the volume resistivity values of the composites decreased by more than 17 orders of magnitude. At such high filler concentrations, the dielectric constant values of the composite samples increased considerably, to values that were greater than 1000. The permeability values of the samples increased linearly with the volume fraction of the nickel filler and were insensitive to the shape of the fillers. The highest relative permeability value measured was 5.8 for composites with 67% by volume of nickel powder. © 1993 John Wiley & Sons, Inc.  相似文献   

6.
Polypropylene/(wood flour)/(kenaf fiber) hybrid composites were prepared in an internal mixer. Kenaf was considered as a fibrous filler and wood flour as a particulate filler. The lignocellulosic loading used was 50%. Dynamic mechanical thermal analysis properties such as storage modulus (E′), loss modulus (E″), damping factor (tan δ), and adhesion factor were evaluated. It was found that the adhesion factor could interpret the interfacial adhesion between lignocellulosic fillers and the plastic matrix macroscopically. This factor was affected by the type of filler used and the coupling agent concentration. The variation of storage modulus was affected more by the shape of the filler and the coupling agent concentration at higher temperatures than at temperatures below the glass transition. Owing to a higher probability of agglomeration in a sample containing 50 wt% of wood flour, the storage modulus and complex viscosity of this sample were higher than those of other samples. Cole‐Cole diagrams showed that the homogeneity of samples containing a higher amount of coupling agent was higher than that of samples with a lower concentration. J. VINYL ADDIT. TECHNOL., 2009. © 2009 Society of Plastics Engineers  相似文献   

7.
Studies of the effect of particulate fillers on specific mechanical properties of vinyl ester epoxy (VE) reinforced with woven glass fiber composites were carried out with different filler types and particulate filler contents (1%, 3%, and 5% by weight). Two types of particulate filler were used, i.e., calcium carbonate (CC) and phenolic hollow microspheres (PHMS). The composites were prepared by using a hand lay‐up and vacuum bagging method. Woven glass fabric composites filled with particulate PHMS were observed to have better specific flexural strength and specific impact strength, as well as lower density, than those filled with particulate CC. Morphological features determined by scanning electron microscope (SEM) proved that the PHMS filler experienced good bonding in the VE matrix, a feature which contributed to the improvement in the properties of the composites. The incorporation of particulate fillers into the composites also influenced the storage modulus with a minimal effect on Tg. J. VINYL ADDIT. TECHNOL., 2010. © 2010 Society of Plastics Engineers  相似文献   

8.
Hybrid composites based on poly(ether‐ether‐ketone) (PEEK) were fabricated with fly ash and mica. Nearly 5, 10, and 15 wt% of fly ash were replaced by mica of the optimized fly ash reinforced composites and were subjected to dynamical mechanical analysis to determine the dynamic properties as a function of temperature. The storage modulus E′ was found to decrease with the increase of weight fraction of mica. Loss modulus was also found to decrease with loading while the damping property was found to increase marginally. Peak height of tan δ for hybrid composites were decreased by varying combinations of fly ash with mica. It is probably due to improved crystallinity of PEEK and strong interaction between the fillers and PEEK matrix. Cole–Cole analysis was made to understand the phase behavior of the composite samples. Kubat parameter was calculated to study the adhesion between matrix and filler of the fabricated composites. Without surface modification for inorganic fillers, the distribution of two different shape filler particles appears to be reasonably uniform. The use and limitation of various theoretical equations to predict the tan δ and storage modulus of filler reinforced composites have been discussed. Addition of both fillers opens up new opportunities for development of high‐performance multifunctional materials suitable for industrial applications. Scanning electron micrographs of tensile fracture surfaces of composites demonstrated filler–matrix bonding. POLYM. COMPOS., 35:68–78, 2014. © 2013 Society of Plastics Engineers  相似文献   

9.
Ritesh Kaundal 《SILICON》2018,10(6):2439-2452
The present work was carried out for the utilization of major quantities of flyash as filler material in the short fiber reinforced polyester resin composites in various engineering and structural applications. The incorporation of flyash modifies the hardness, tensile, flexural, impact and damping behavior of the composites. It is observed that hardness, flexural modulus and impact strength of flyash filled composites increases with increase in the flyash filler contents. Whereas, with the addition of flyash contents it is observed that there is decrease in tensile strength and flexural strength. But beyond the 10 wt.-% flyash filler addition in the composite the flexural strength increases. At the end, the erosion wear behavior of all the composites has been studied by Taguchi experimental design. It is found that unfilled glass polyester composite suffers greater erosion loss as compare to particulate filled glass polyester composites. The eroded surface morphology is examined by SEM and the related erosion wear mechanism is discussed in detail.  相似文献   

10.
In this study, natural sawdust fillers from acacia were mixed with unsaturated polyester resin (UPR), which was prepared by recycling of polyethylene terephthalate (PET) waste bottles to prepare sawdust/UPR composite. PET wastes were recycled through glycolysis and depolymerized to produce a formulation for the resin. The effects of alkali treatment, filler content, and filler size on the tensile, flexural, hardness, and water absorption of the composites were investigated. The results show that the modulus of both tensile and flexural increased with increasing filler contents, but the tensile and flexural strength of composites decreased. The size of sawdust also played a significant role in the mechanical properties, with smaller size sawdust producing higher strength and modulus. This is due to the greater surface area for filler–matrix interaction. The results also show that alkali treatment causes a better adhesion between sawdust and UPR matrix and improves the mechanical properties of the composites. Furthermore, surface treatment reduced the water absorption of composites. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008  相似文献   

11.
Electrically and thermally conductive resins can be produced by adding carbon fillers. Mechanical properties such as tensile modulus, ultimate tensile strength, and strain at ultimate tensile strength are vital to the composite performance in fuel cell bipolar plate applications. This research focused on performing compounding runs followed by injection molding and tensile testing of carbon filled Vectra A950RX liquid crystal polymer composites. The four carbon fillers investigated included an electrically conductive carbon black, thermocarb synthetic graphite particles, and two carbon fibers (Fortafil 243 and Panex 30). For each different filler type, resins were produced and tested that contained varying amounts of these single carbon fillers. The carbon fiber samples exhibited superior tensile properties, with a large increase in tensile modulus over the base polymer, and very low drop in the ultimate tensile strength as the filler volume fraction was increased. The strain at the ultimate tensile strength was least affected by the addition of the Panex carbon fiber but was significantly affected by the Fortafil carbon fiber. In general, composites containing synthetic graphite did not perform as well as carbon fiber composites. Carbon black composites exhibited poor tensile properties. POLYM. COMPOS., 29:15–21, 2008. © 2007 Society of Plastics Engineers  相似文献   

12.
Dynamic modulus of elasticity (MoE) and shear modulus of wood‐filled polypropylene composite at various filler contents ranging from 10% to 50% was determined from the vibration frequencies of disc‐shaped specimens. Wood filler was used in both fiber form (pulp) and powder form (wood flour). A novel compatibilizer, m‐isopropenyl‐α,α‐dimethylbenzyl‐isocyanate(m‐TMI) grafted polypropylene with isocyanate functional group was used to prepare the composites. A linear increase in dynamic MoE, shear modulus, and density of the composite was observed with the increasing filler content. Between the two fillers, wood fiber filled composites exhibited slightly better properties. At 50% filler loading, dynamic MoE of the wood fiber filled composite was 97% higher than that of unfilled polypropylene. Halpin‐Tsai model equation was used to describe the changes in the composite modulus with the increasing filler content. The continuous improvement in elastic properties of the composites with the increasing wood filler is attributed to the effective reinforcement of low‐modulus polypropylene matrix with the high‐modulus wood filler. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1706–1711, 2006  相似文献   

13.
Two nanosized carbonaceous fillers, vapor grown carbon nanofibers and exfoliated graphite nanoplatelets, were used to prepare poly(lactide acid) composites at various concentrations from 0 up to 20 wt.%. The two fillers were also combined in order to explore possible synergistic actions. Two compounding processes, melt mixing and polymer dissolution, and two forming methods, injection and compression molding, were used to manufacture the composites. The flexural properties, impact strength, storage and loss modulus, Vicat softening temperature, and electrical conductivity of neat matrix and composites were determined as a function of the filler type and content, and of the processing method used. The filler dispersion within the polymer matrix, the presence of agglomerates and the existence of voids were studied using field-emission scanning electron microscopy. It is concluded that compounding by polymer dissolution followed by compression molding leads to composites with the lowest percolation threshold and surface conductivity and highest storage modulus whereas extrusion injection molding results in composites with the highest mechanical properties. The results can be used to engineer biodegradable composites with specific properties for targeted applications.  相似文献   

14.
The linearity of the modulus of elasticity of a randomly reinforced composite as a function of the volume content of fibre filler is experimentally established. The basic factors that determine the modulus of elasticity of the thermoplastic composite are determined: the modulus of elasticity, shape, and volume content of filler. The modulus of elasticity of the composite is not a function of the adhesion of the fibre filler to the matrix. Realization of the strength of fibre fillers in randomly reinforced composites should obey the mechanisms that hold for unidirectional, continuously reinforced composites with consideration of the effect of the filler and process parameters on the rheology and morphology of the binder.  相似文献   

15.
Recycled high‐density polyethylene (RHDPE)/coir fiber (CF)‐reinforced biocomposites were fabricated using melt blending technique in a twin‐screw extruder and the test specimens were prepared in an automatic injection molding machine. Variation in mechanical properties, crystallization behavior, water absorption, and thermal stability with the addition of fly ash cenospheres (FACS) in RHDPE/CF composites were investigated. It was observed that the tensile modulus, flexural strength, flexural modulus, and hardness properties of RHDPE increase with an increase in fiber loading from 10 to 30 wt %. Composites prepared using 30 wt % CF and 1 wt % MA‐g‐HDPE exhibited optimum mechanical performance with an increase in tensile modulus to 217%, flexural strength to 30%, flexural modulus to 97%, and hardness to 27% when compared with the RHDPE matrix. Addition of FACS results in a significant increase in the flexural modulus and hardness of the RHDPE/CF composites. Dynamic mechanical analysis tests of the RHDPE/CF/FACS biocomposites in presence of MA‐g‐HDPE revealed an increase in storage (E′) and loss (E″) modulus with reduction in damping factor (tan δ), confirming a strong influence between the fiber/FACS and MA‐g‐HDPE in the RHDPE matrix. Differential scanning calorimetry, thermogravimetric analysis thermograms also showed improved thermal properties in the composites when compared with RHDPE matrix. The main motivation of this study was to prepare a value added and low‐cost composite material with optimum properties from consumer and industrial wastes as matrix and filler. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42237.  相似文献   

16.
《Polymer Composites》2017,38(5):870-876
Thermally conductive fillers are usually employed in the preparation of rubber composites to enhance thermal conductivity. In this work, ethylene‐propylene‐diene monomer rubber (EPDM)/expanded graphite (EG) and EPDM/graphite composites with up to 100 phr filler loading were prepared. Compared to EPDM/graphite compounds with the same filler loading, stronger filler network was demonstrated for EPDM/EG compounds. Thermal conductivity and mechanical properties of EPDM/graphite and EPDM/EG composites were compared and systematically investigated as a function of the filler loading. The thermal conductivity of both EPDM/graphite and EPDM/EG composites increased with increasing volume fraction of fillers, and could be well fitted by Geometric Mean Model. The thermal conductivity as high as 0.910 W · m−1 · K−1 was achieved for the EPDM/EG composite with 25.8 vol% EG, which was ∼4.5 times that of unfilled EPDM. Compared to EPDM/graphite composites, EPDM/EG composites exhibited much more significant improvement in thermal conductivity and mechanical properties, which could be well correlated with the better filler‐matrix interfacial compatibility and denser structure in EPDM/EG composites, as revealed in the SEM images of tensile fracture surfaces. POLYM. COMPOS., 38:870–876, 2017. © 2015 Society of Plastics Engineers  相似文献   

17.
The damping coefficient (tanδ) of wood flour filled polypropylene composites, having varying filler concentrations were measured using the free vibration decay of disk‐shaped specimen, vibrating in flexural vibration mode. The damping coefficients decreased with the increase of filler load in composites. There was no significant difference in damping behavior of composites with and without compatiblizer at low filler level (upto 30%). At higher filler loading (>30%), composites with compatiblizer had lower damping coefficient suggesting improved interfacial adhesion between wood and polypropylene. The damping in composite is attributed to the damping because of the composite constituents and damping at the interface. The damping because of interface was estimated using a model and was found to increase with the increase in filler loading. At higher filler content, damping due to interface in composites with compatiblizer was significantly lower than in composites without compatiblizer suggesting a better interfacial adhesion between the wood filler and polypropylene matrix with compatiblizer. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009  相似文献   

18.
The objective of this research article is to compare the mechanical and tribological properties of jute‐glass‐fiber‐reinforced epoxy (J‐G‐E) hybrid composites with and without fly ash particulate filler. A dry hand lay‐up technique is used to fabricate all the laminates. The properties including flexural strength, tensile strength, flexural modulus, and erosion behavior of all the composites are evaluated as per American Society for Testing and Materials (ASTM) standards. The fly ash particulate‐filled hybrid composite shows a better mechanical and tribological property. The maximum flexural strength and flexural modulus are obtained for GJGJ+ 5 wt% fly ash filler epoxy composites. Whereas the maximum tensile strength is obtained for GJJG+ 10 wt% fly ash filler epoxy composites. Scanning Electron Microscopy (SEM) analysis also has been carried out to categorize mechanical and tribological behavior of composites. POLYM. COMPOS. 37:658–665, 2016. © 2014 Society of Plastics Engineers  相似文献   

19.
The application of dynamic mechanical analysis (DMA) for quantifying interfacial interactions in composites is briefly reviewed. Carbon fiber/epoxy composites with fiber volume fractions of 12, 17, 38 and 61 vol% were subjected to flexural deformation on a Dupont DMA 983 instrument. The dependencies of dynamic mechanical properties of the composites on experimental parameters such as oscillation mode, amplitude, frequency, and temperature were investigate. As opposed to the storage modulus, the loss modulus is found to be sensitive to all parameters. In a fixed multiple frequency mode, the loss modulus of the composites increases with oscillation amplitude and decreases with frequency and the number of tests. The information produced in the resonant mode is more reproducible. An additional damping at the interfaces, apart from those of the constituents, suggests a poor interface adhesion in these composites. A linear relationship between the excess damping at the interfaces and the fiber volume fraction shows a similar interface quality for these composites having different fiber volume fractions. The detection of interfacial properities was found to be more sensitive in the flexural deformation mode than in the torsional mode. At temperatures higher than the glass transition temperature of the matrix, the effective volume fraction of the matrix is reduced. Such a reduction can be interpreted from the mismatch of thermal expansion of the matrix and the fibers.  相似文献   

20.
Mechanical strengths of a banana pseudo-stem (BPS) fiber and unplasticized polyvinyl chloride (UPVC) composite were evaluated to assess the possibility of using it as a new material in engineering applications. Samples were fabricated by the compression molding process with reference to the effect of filler loading. The samples were submitted to mechanical tests to measure tensile, flexural, and impact properties of the composites. The nature of adhesion between the matrix and the reinforcement and information relating the structure of mechanical properties can be obtained by scanning electron microscopy (SEM) assessment of the composite fracture surface. The mechanical properties show that the composites did not have good adhesion between filler and matrix; on the other hand, the filler insertion improved the flexural modulus and the material rigidity.  相似文献   

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