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1.
The mechanical and thermal behavior of compression molded jute/polypropylene (PP) composites were studied by evaluating tensile strength (TS), bending strength (BS), tensile modulus (TM), bending modulus (BM), impact strength (IS), thermogravimetric (TG/DTG) and differential thermal analysis (DTA). A chemical modification was made to jute fabrics using N,N-Dimethylaniline (DMA) in order to improve the interfacial adhesion between the fabrics and matrix. It was found that jute fabrics on treatment with N,N-Dimethylaniline (DMA) significantly improved the mechanical properties of the composites. Thermal analytical data of PP, both treated and untreated jute fabrics as well as composites revealed that DMA treatment increased the thermal stability of the fabrics and composite. DMA treatment also reduced the hydrophilic nature of the composite. DMA treated jute composite was found less degradable than control composite under water, soil and simulated weathering conditions.  相似文献   

2.
Castor oil was converted to maleated castor oil (MACO) without any catalyst. MACO was characterized with FTIR, NMR, molecular weight and viscosity measurement. Tung oil (20 wt%) was added to MACO as reactive diluent. Non-woven jute felts were used as reinforcing material. The MACO was polymerized and crosslinked in situ during composite fabrication. The curing behavior of MACO with free radical catalyst was investigated by differential scanning calorimetry (DSC). The MACO/jute composites were tested for their flexural properties, impact strength and dynamic mechanical properties and compared with similar unsaturated polyester resin/jute composites. The flexural moduli of both the composites were nearly similar. The impact strength of MACO/jute composites was 42% higher than that of UPE/jute composites. The damping property of the MACO/jute composites was higher than that of UPE/jute composites over a wide range of temperature.  相似文献   

3.
Jute fabrics reinforced thermoset composites were prepared with different formulations using urethane acrylate oligomer, methanol, and benzyl peroxide. Jute fabrics were soaked in the prepared formulations and fiber content in the composites was optimized with the extent of mechanical properties. Among all the resulting composites, 55 wt% jute content at oligomer:methanol:benzyl peroxide=75:24.5:0.5 (w/w/w) ratio showed best mechanical properties. The optimized jute fabrics were cured under UV radiation at different intensities and their mechanical properties were measured. Jute fabrics were treated with potassium permanganate (KMnO4) solution of different concentrations (0.01, 0.02, 0.03, and 0.05 wt%) for different soaking times (1–5 min) before the composite fabrication. Optimized jute fabrics (jute fabrics treated with 0.02 wt% KMnO4 for 2 min soaking time) were soaked in the optimized formulation and cured under UV radiation at different intensities and measured their mechanical properties. Scanning electron microscopic investigation showed that surface modification improves fiber/matrix adhesion. Water uptake and soil degradation test of the treated and untreated composite samples were also performed.  相似文献   

4.
Composites were prepared with 13, 23 30 and 40 % fiber and evaluated the mechanical performance in tensile, flexural and impact. The mechanical properties of these composites were also evaluated function of time at 110 °C thermal exposure. Caroa fibers were characterized by techniques such as thermal gravimetric analysis (TGA), X-ray diffraction (XRD) and scanning electron microscopy (SEM). It was found that the best mechanical properties were achieved for composites containing 23 to 30 % fiber. The incorporation of 23 % fiber caroa increased both the modulus of elasticity in the tensile test as the flexural strength and impact, the composite with 30 % fiber caroa showed higher tensile strength. The results show that the tensile and flexural strength of the composite decreased with time of thermal exposure. The thermal aging at 110 °C caused a decrease in tensile properties of the composites.  相似文献   

5.
Chemical treatment is an often-followed route to improve the physical and mechanical properties of natural fiber reinforced polymer matrix composites. In this study, the effect of chemical treatment on physical and mechanical properties of jute fiber reinforced polypropylene (PP) biocomposites with different fiber loading (5, 10, 15, and 20 wt%) were investigated. Before being manufactured jute fiber/PP composite, raw jute fiber was chemically treated with succinic anhydride for the chemical reaction with cellulose hydroxyl group of fiber and to increase adhesion and compatibility to the polymer matrix. Jute fiber/PP composites were fabricated using high voltage hot compression technique. Fourier Transform Infrared spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) tests were employed to evaluate the morphological properties of composite. Succinic anhydride underwent a chemical reaction with raw jute fiber which was confirmed through FTIR results. SEM micrographs of the fractured surface area were taken to study the fiber/matrix interface adhesion and compatibility. Reduced fiber agglomeration and improved interfacial bonding was observed under SEM in the case of treated jute fiber/PP composites. The mechanical properties of jute/PP composite in terms of Tensile strength and Young’s modulus was found to be increased with fiber loading up to 15 wt% and decreased at 20 wt%. Conversely, flexural strength and flexural modulus increased with fiber loading up to 10 wt% and start decreasing at 15 wt%. The treated jute/PP composite samples had higher hardness (Rockwell) and lower water absorption value compared to that of the untreated ones.  相似文献   

6.
In this paper, the effects of heat treated parameters on the properties of bamboo fiber (BF) / polypropylene (PP) composites were investigated. The crystallization properties of BF/PP composites after heat treatment were characterized by differential scanning calorimetry (DSC), and the mechanical properties were measured. The results showed that the crystallinities of the heat treated composite were enhanced compared with that of the untreated. When the heat treated time was 30 mins, the crystallinities became almost unchanged. However, the crystallinity decreased after 12 h heat treatment. In addition, when the heat treated temperature was above 90 °C, the higher the temperature was, the higher the crystallinities became. Moreover, the tensile strengths of BF/PP composites increased and then decreased with increasing heat treated time, while the impact strengths had a decreasing trend. In the meanwhile, the tensile strengths increased but the impact strengths decreased as the heat temperature increased.  相似文献   

7.
Denim, a twilled cotton fabric, was used to enhance the mechanical and thermal properties of poly(lactic acid) (PLA). The denim fabric reinforced composites with different numbers of denim layers were fabricated by using a hand layup method. The impact, tensile, and dynamic mechanical properties of the composites were observed with increasing denim layers to examine the reinforcing effect of denim fabrics. Numerical analysis was carried out to model the elastic modulus of the composite by using a commercial software. Three-dimensional geometry of the denim fabric reinforced PLA composite was generated through a CAD program, and the elastic modulus was calculated by applying uniform deformation on one surface. The impact strength, tensile strength, and thermal properties of the composites were improved by piling denim fabrics. The denim fabric reinforced composites exhibited outstanding impact strength due to the retarded crack propagation as well as large energy dissipation. The 3 layer denim reinforced composite showed best results among all specimens, and its impact strength, tensile strength, and tensile modulus were measured to be 82 J/m, 75.76 MPa, and 4.65 GPa, respectively. The PLA/denim composites have good mechanical properties and can substitute traditional composites such as glass fiber or carbon fiber reinforced composites.  相似文献   

8.
This study aims to investigate the effects of two types of wood flour; oil palm mesocarp flour (OMF) and rubberwood flour (RWF), and their particle sizes on mechanical, physical, and thermal properties of wood flour reinforced recycled polypropylene (rPP) composites. The composite materials were manufactured into panels by using a twin-screw extruder. The rPP composites based on RWF significantly showed higher flexural, tensile, and compressive properties (both strength and modulus) as well as hardness and thermal stability than those composites based on OMF for the same particle sizes. However, distribution of RWF in the rPP matrix was less homogeneous than that of the rPP/OMF composites. Furthermore, a decrease of the particle sizes of filler for the rPP/OMF or RWF composites increased the flexural, tensile, compressive, and hardness properties. Likewise, the thermal stability of both OMF and RWF composites were insignificantly affected by the particle sizes.  相似文献   

9.
Jute fabric reinforced polypropylene composites were fabricated by compression molding technique. Fiber content in the composites was optimized at 45 % by weight of fiber by evaluating the mechanical parameters such as tensile strength, tensile modulus, bending strength, bending modulus. Surface treatment of jute fabrics was carried out by mercerizing jute fabrics with aqueous solutions of NaOH (5, 10 and 20 %) at different soaking times (30, 60 and 90 mins) and temperatures (0, 30 and 70 °C). The effect of mercerization on weight and dimension of jute fabrics was studied. Mechanical properties of mercerized jute-PP composites were measured and found highest at 20 % NaOH at 0 °C for 60 min soaking time. Thermal analytical data from thermogravimetric and differential thermal analysis showed that mercerized jute-PP composite achieved higher thermal stability compared to PP, jute fabrics and control composite. Degradation characteristics of the composites were studied in soil, water and simulated weathering conditions. Water uptake of the composites was also investigated.  相似文献   

10.
Natural fiber composite replaces the conventional and synthetic materials in many fields especially in light weight applications. The randomly oriented short snake grass fiber reinforced isophthallic polyester composites are prepared by hand lay-up technique and finally compression molded. The various length and weight fraction of fiber are used in composite fabrication. The mechanical properties and water absorption under various climatic conditions are examined according to the prescribed standard. SEM image revealing the fiber pullout and breakage of the tensile and impact fractured composite specimens has been analysed and compared with control through scanning electron microscope. The result shows that the mechanical properties increase with increase in fiber length and weight fraction of the composites. The rate of water absorption increases with increase in temperature and time. Obtained experimental tensile strength of the composite is compared with various theoretical models such as Series, Hirsch’s, Halpin-Tsai, Modified Halpin-Tsai and Modified Bowyer & Brader’s and the obtained inferences are discussed.  相似文献   

11.
Sugar palm fiber is one of the most abundant natural fibers used in biocomposites. However, prediction of the mechanical properties of such natural fiber reinforced composites is still challenging. Most of the theoretical modelings are based the micromechanical method. There have been little studies involving statistical approach for prediction of mechanical properties of natural fiber reinforced composites. In this study, the tensile properties of short sugar palm fiber-reinforced high impact polystyrene (SPF-HIPS) composites obtained by means of statistical approach were investigated and compared with the experimental observations and with micromechanical models available in the literature. Statistical approach was used to predict the performance of the composite part with different fiber loadings. A two-parameter Weibull distribution function was used to model the fiber length distribution in the composite. For the experimental validation, the composites were prepared by hot compression technique for different fiber loadings (10 %, 20 %, 30 %, 40 % and 50 % by weight). Tensile testing of the composites was carried out according to ASTM D638 to obtain the composites tensile strength and modulus of elasticity. Experimental results showed that the tensile strength of the composite reduced due to the addition of sugar palm fibers, whereas the elastic modulus increased by a factor of up to 1.34. The current statistical model predicted the tensile properties of SPF-HIPS composite close to the experimental values. It was found that statistical approach with standard micromechanical models can be used to predict the mechanical properties of sugar palm fiber reinforced HIPS composites. Hence, this study could assist in decisions regarding the design of natural fiber reinforced composite products.  相似文献   

12.
We investigated the surface modification of jute fiber by oxygen plasma treatments. Jute fibers were treated in different plasma reactors (radio frequency “RF” and low frequency “LF” plasma reactors) using O2 for different plasma powers to increase the interface adhesion between jute fiber and polyester matrix. The influence of various plasma reactors on mechanical properties of jute fiber-reinforced polyester composites was reported. Tensile, flexure, short beam shear tests were used to determine the mechanical properties of the composites. The interlaminar shear strength increased from 11.5 MPa for the untreated jute fiber/polyester composite to 19.8 and 26.3 MPa for LF and RF oxygen plasma treated jute fiber/polyester composites, respectively. O2 plasma treatment also improved the tensile and flexural strengths of jute fiber/ polyester composites for both plasma systems. It is clear that O2 plasma treatment of jute fibers by using RF plasma system instead of using LF plasma system brings about greater improvement on the mechanical properties of jute/polyester composites.  相似文献   

13.
The chemical and morphological properties of ramie fibers treated by chemical surface modification were examined with Fourier transform infrared (FT-IR) spectroscopy. The mechanical and thermal decomposition properties were evaluated with respect to tensile strength, tensile modulus and thermogravimetric analysis (TGA). Surface morphological changes were investigated with scanning electron microscopy (SEM). Finally, the capabilities of composites reinforced with various chemically treated fibers were analyzed by investigating tensile and impact strengths. Additionally, the thermal mechanical properties of the composites were investigated with thermal mechanical analysis (TMA). Based on the results of these analyses, we concluded that pectin, lignin and hemicellulose were removed and thermal stability was increased with chemical treatments. The composites reinforced with ramie fiber showed better properties compared with pure PLA matrix with respect to tensile and impact strengths. The peroxide-treated fiber composite had the smallest thermal expansion.  相似文献   

14.
Natural fibers are largely divided into two categories depending on their origin: plant based and animal based. Plant based natural jute fiber reinforced polypropylene (PP) matrix composites (20 wt% fiber) were fabricated by compression molding. Bending strength (BS), bending modulus (BM), tensile strength (TS), Young’s modulus (YM), and impact strength (IS) of the composites were found 44.2 MPa, 2200 MPa, 41.3 MPa, 750 MPa and 12 kJ/m2, respectively. Animal based natural B. mori silk fiber reinforced polypropylene (PP) matrix composites (20 wt% fiber) were fabricated in the same way and the mechanical properties were compared over the silk based composites. TS, YM, BS, BM, IS of silk fiber reinforced polypropylene composites were found 55.6 MPa, 760 MPa, 57.1 MPa, 3320 MPa and 17 kJ/m2 respectively. Degradation of composites in soil was measured upto twelve weeks. It was found that plant based jute fiber/PP composite losses its strength more than animal based silk fiber/PP composite for the same period of time. The comparative study makes it clear that mechanical properties of silk/PP composites are greater than those values of jute/PP composites. But jute/PP composites are more degradable than silk/PP composites i.e., silk/PP composites retain their strength for a longer period than jute/PP composites.  相似文献   

15.
Although the pineapple leaf fibers (PALF) are long known as domestic threading material in Malaysia, they are currently of little use despite being mechanically and environmentally sound. This study evaluated some selected properties of Josapine PALF and PALF-vinyl ester composites as well as the effects of simple abrasive combing and pretreatments on fiber and composite properties. Using PALF vascular bundles extracted from different parts of the leaves did not significantly affect PALF-vinyl ester composite mechanical properties. At low weight fraction and consolidating pressure, PALF fibers regardless of diameters and locations performed equally well in enhancing composite flexural properties under static loading. Finer bundles enhanced PALF-vinyl ester composite toughness indicated by tests at higher speeds. Abrasive combing produces cleaner and finer bundles suitable for reinforcing composites for applications not requiring high toughness.  相似文献   

16.
Intra-layer and inter-layer hybrid composite laminates were made with epoxy resin and compositions were varied in six different proportions. In-plane compressive mechanical properties were studied using finite element analysis and experiments, and the results found were in good agreement. Properties of intra-layer and inter-layer hybrids were compared with plain carbon/epoxy and plain glass/epoxy composites, and a comparison among themselves was also made. It was found that intra-layer hybrids to some extent exhibit better compressive properties compared to inter-layer hybrids. Percentage enhancement in compressive failure strain was noticed. Negative hybrid effects on compressive strength was noticed for both intra-layer and inter-layer hybrid configurations. It was found that proportion of carbon fiber content plays a key role in determining the compressive properties. According to macro-scale observation all composite laminates failed catastrophically under compressive loading. SEM observation depicted that under compressive loading carbon fibers break first followed by glass fiber.  相似文献   

17.
Multi-walled carbon nanotubes (MWCNTs) were functionalized with hyperbranched aromatic polyamide (HAP) by in situ polymerization and by the AB 2 approach to enhance the mechanical properties of poly(methylmethacrylate) (PMMA) composites. Various concentrations of HAP-functionalized MWCNTs (HAP-f-MWCNTs) were used to prepare HAP-f-MWCNT-reinforced PMMA composite films. The covalent attachment of HAP to the MWCNTs, as achieved by in situ functionalization, resulted in effective dispersion of the MWCNTs in the PMMA matrix, thus enhancing the mechanical and thermal properties of the composite films. The breaking stress of the composites increased largely with the HAP-f-MWCNT loading.  相似文献   

18.
Composites based on pure Basalt and Basalt/Jute fabrics were fabricated. The mechanical properties of the composites such as flexural modulus, tensile modulus and impact strength were measured depending upon weave, fiber contents and resin. Dynamic mechanical analysis of all composites were done. From the results it is found that pure basalt fiber combination maintains higher values in all mechanical tests. Thermo-gravimetric (TG/DTG) composites showed that thermal degradation temperatures of composites shifted to higher temperature regions compared to pure jute fabrics. Addition of basalt fiber improved the thermal stability of the composite considerably. Scanning electron microscopic images of tensile fractured composite samples illustrated that better fiber-matrix interfacial interaction occurred in hybrid composites. The thermal conductivity of composites are also investigated and thermal model is used to check their correlation.  相似文献   

19.
Enhancement of the mechanical and vibrational properties of glass/polyester composites was aimed via matrix modification technique. To achieve this, unsaturated polyester was modified by incorporation of oligomeric siloxane in the concentration range of 1–3 wt%. Modified matrix composites reinforced with woven roving glass fabric were compared with untreated glass/polyester in terms of mechanical and interlaminar properties by conducting tensile, flexure, and short-beam shear tests. It was found that after incorporation of 3 % oligomeric siloxane into the polyester matrix, the tensile, flexural, and interlaminar shear strength (ILSS) values of the resulting composite increased by 16, 15, and 75 %, respectively. The increases in ILSS as well as in tensile and flexural properties were considered to be an indication of better fiber/matrix interaction as confirmed by SEM fractography images. Furthermore, the effect of oligomeric siloxane incorporation on the vibrational properties of the composites was investigated by experimental modal testing and the natural frequencies of the composites were found to increase with increasing siloxane concentration.  相似文献   

20.
Present research investigates the mechanical properties of jute-coir fiber reinforced hybrid polypropylene (PP) composite with fiber loading variation and observes the effect of chemical treatment of fiber on property enhancement of the composites. Composites were manufactured using hot press machine at four levels of fiber loading (5, 10, 15 and 20 wt%). Fiber ratio’s were varied (jute:coir=1:1, 3:1 and 1:3) for 20 % fiber loaded composites. Both jute and coir fiber was treated using 5 % and 10 % NaOH solutions. Composites were also prepared using treated fiber with jute-coir fiber ratio of 3:1. Tensile, flexural, impact and hardness tests and Fourier transform infrared spectroscopic analysis were conducted for characterization of the composites. Tensile test of composite showed a decreasing trend of tensile strength and increasing trend of the Young’s modulus with increase in fiber loading. During flexural, impact and hardness tests, the flexural strength, flexural modulus, impact strength and hardness values were found to be increased with increase in fiber loading. All these properties enhanced with the enhancement of jute content except impact strength. 5 % NaOH treatment provided an improving trend of properties whereas, 10 % NaOH treatment showed the reverse one. The FTIR analysis of the composites indicated decrease of hemicelluloses and lignin content with alkali treatment.  相似文献   

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