Polyester-based Hybrid Composites Research Articles

Effect of Water Absorption on the Tensile Characteristics of Natural/ Synthetic Fabrics Reinforced Hybrid Composites

The effect of water absorption and swelling thickness on the tensile properties of flax/sisal/carbon/glass fabrics reinforced by unsaturated polyester-based hybrid composites was evaluated. Hybrid composites reinforced with different natural and synthetic fiber configurations have been processed using the Hand lay-up (HLU) technique. Water absorption test was carried out by immersing specimens in distilled water for different lengths of time, up to 1344 hours, and showed slight enhancement of water absorption for fibers configuration [C/C/C/C/C/C] up to 1.45%, but great enhancement of water absorption for fiber configuration [S/S/S/S/S/S] up to 14%. The tensile strength of samples before and after immersion in distilled water was evaluated. This result showed that the tensile strength of fibers configuration [C/C/F/F/C/C] is approaching fibers configuration [C/C/C/C/C/C] at dry condition. Fractured cross-section morphology of composites was investigated using scanning electron microscopy (SEM) to evaluate the fibers/matrix interface before and after hydro aging. The reduction in tensile strength due to water penetrating is slight for hybrid composite with synthetic fibers at the outer layer, but huge for hybrid composite with natural fibers at outer layer.

Performance studies of polyester-based hybrid composites reinforced with palmyra-palm leaf stalk and glass fibers

The present work aimed to analyze the retrospective effects of stacking sequence on water uptake behavior and mechanical strength of PPLS/glass fiber polyester laminates. The composite laminates were fabricated with different stacking sequence and exposed to water by immersing it at a room temperature for a period of 20 days. For studying the mechanism of water transport in the laminate, the laminates were weighted in regular interval of 24 h. From the results, it is observed that irrespective of stacking sequence, the mechanism of water transport follows the law of Fickian’s diffusion. Again, reduction in mechanical properties due to water uptake was also noticed. However, a substantial recovery of properties was observed on complete removal of water particle by desiccation.

Experimental study on tribological (dry sliding wear) behaviour of polyester matrix hybrid composite reinforced with particulate wood charcoal and periwinkle shell

Polyester based hybrid composites is developed using 75 µm sized wood charcoal and periwinkle shell as particulate reinforcements in various proportions of mixture. Hardness, dry sliding wear and morphological examinations were performed on the hybrid composite samples using Brinell hardness tester, pin-on-disc tribometer and SEM-EDX techniques respectively. The results from the study revealed that all the hybrid composites have improved properties over the unreinforced polyester resin and polyester sample reinforced with only wood charcoal at 5 wt% reinforcement concentration. Optimal combination of hardness and wear properties was obtained by the hybrid composite sample reinforced with equal proportions of wood charcoal and periwinkle shell particles. Further additions of periwinkle shell particles over the content of wood charcoal powder in the 25:75 ratio, induced a sharp decrease in hardness and wear properties of the hybrid composites below that of the unreinforced polyester resin. SEM-EDX analysis revealed the presence of varying proportions of carbon, calcium, silicon, potassium, iron and aluminium as the major elements, which resulted in the observed hardness, and wear properties of the hybrid composites. Optimal reinforcement weight fraction and combination of wear parameters required for minimum wear rate and improved hardness was established using one factor RSM design.

Evaluation of some Properties of Polyester Based Hybrid Composites Produced From Luffa-Bananna Fibres

This study presents the evaluation of the mechanical, physical and dynamic mechanical properties of luffa-banana fibre reinforced polyester hybrid composites. The luffa fibre and banana fibres were extracted from luffa plant and banana stem respectively by manual stripping into strands. The luffa and banana fibres were then blended in the ratio of 50:50 for the production of the hybrid composites using hand lay-up method. Polyester-resin was used as binder and the percentages of luffa-banana fibres used were 3, 5, 6, and 9 %. The tensile strength, impact strength, flexural strength, density, water absorption, and the dynamic mechanical analysis (DMA) (storage modulus, loss modulus damping factor) of the produced luffa-banana hybrid composites were evaluated. The results of the density and water absorption obtained varied from 0.84-1.23 g/cm3 and 0 - 0.35 % respectively. The tensile and impact strengths (3.46 - 9.27 MPa and 0.66-3.26 J/cm2) of the produced hybrid composites were observed to increase with increasing fibre content from 3 - 6 % and decreased at 9 %. The results of DMA revealed that loss modulus of the hybrid composites and pure polyester were found to increase with increasing temperature up to glass transition temperature and then decreased. The damping factor was observed to increase with increasing temperature and goes at maximum level in transition region and while decreasing the in rubbery region. The properties of the produced hybrid luffa-banana composites showed that luffa and banana fibres can be used in synergy as raw materials for composites manufacture. As the properties evaluated were in agreement with standard composites used as interior design of cars.

Mechanical behavior of glass fiber polyester hybrid composite filled with natural fillers

Now-a-days, the natural fibers and fillers from renewable natural resources offer the potential to act as a reinforcing material for polymer composite material alternative to the use of synthetic fiber like as; glass, carbon and other man-made fibers. Among various natural fibers and fillers like banana, wheat straw, rice husk, wood powder, sisal, jute, hemp etc. are the most widely used natural fibers and fillers due to its advantages like easy availability, low density, low production cost and reasonable physical and mechanical properties This research work presents the effect of natural fillers loading with 5%, 10% and 15% on mechanical behavior of polyester based hybrid composites. The result of test depicted that hybrid composite has far better properties than single fibre glass reinforced composite under impact and flexural loads. However it is found that the hybrid composite have better strength as compared to single glass fibre composites.

Mechanical characterizations and development of erosive wear model for Al2O3-filled short glass fiber-reinforced polymer composites

In the present work, short glass fiber-reinforced polyester-based hybrid composites are fabricated by the incorporation of Al2O3 particulates with three different weight percentages (0 wt.%, 10 wt.% and 20 wt.%) to evaluate their physical, mechanical, and thermo-mechanical behavior. A theoretical model has been developed for erosive wear conditions and results are compared with the experimental outcomes in order to validate the model. The mechanical properties are simulated using an explicit FE code software ANSYS. In this work, erosion test is conducted by using popular evolutionary Taguchi’s (L27) orthogonal array design to optimize the experimental results. It is observed from the analysis that the peak erosion rate occurs at 75° impingement angle for Al2O3-filled composites, whereas for unfilled composites, it occurs at 60° impingement angle. The thermo-mechanical characteristics such as storage modulus (E′), loss modulus (E″), and damping properties (Tan δ) are investigated in the temperature range of 25–200 ℃. It is observed that the slope corresponding to the temperature-dependent decay of the storage modulus for 10 wt.% and 20 wt.%, Al2O3-filled composite is much higher as compared to 0 wt.% Al2O3-filled composite in the temperature range of 25–75 ℃. However, the storage modulus for 10 wt.% and 20 wt.% Al2O3-filled composites remain almost same in the range of 25–60 ℃. Finally, the surface morphology of the eroded composites is examined by using scanning electron microscope and the possible wear mechanisms are discussed.

Testing of Mechanical Properties of Hybrid Fiber Reinforced Composites

Nowadays Natural fibers such as sisal, flax, hemp, jute, bamboo, banana, etc. are widely used for environmental concern on synthetic fibers (such as glass, carbon, ceramic fibers, etc.). The natural fibers extracted by retting and manual process. Fiber reinforced polymer composites have a wide variety of applications as a class of structural materials because of their advantages such as ease of fabrication, relatively low cost of production and superior strength. There is an increasing interest in hybrid composites because of their increase in mechanical property, the property depends on many factors such as fiber content, orientation, types, length etc. In this connection the objective of the present research work is to replace the chopped method technique by the fabric weaving methods. The weaving methods on sisal and banana fiber reinforced polyester based hybrid composites are analyzed based on the mechanical behavior of hybrid composites. The main advantage of this research is to reduce the weight, cost and to increase the strength of the material.

Tamarind Fruit Fiber and Glass Fiber Reinforced Polyester Composites

Polyester-based hybrid composites were developed by combining the tamarind fruit (Tf) and glass fibers into a polyester matrix. Hardness, impact strength, frictional coefficient, and chemical resistance of hybrid composites with and without alkali treatments were studied. Variation of the aforementioned mechanical properties and chemical resistance was studied with different fiber lengths, such as 1, 2, and 3 cm. A 9 vol% of the tamarind and glass fibers was reinforced into the polyester matrix. The aforementioned mechanical properties were optimally improved at 2-cm fiber length when compared with 1- and 3-cm fiber lengths. Chemical resistance was also significantly improved for all chemicals except toluene. A 3°C rise in decomposition temperature while a 2°C rise in glass transition temperature was observed from TGA and DSC micrograms, respectively.

Preparation and Dimensional Stability of Organo-Montmorillonite (O-MMT) Treated Unsaturated Polyester Hybrid Composites Filled with Keratin Fiber

O-MMT treated unsaturated polyester based hybrid composites were prepared using keratin fiber obtained from chicken feathers. Fibers of similar dimension were selected to fabricate composites through hand lay-up method. The preparation and dimensional stability properties of keratin fiber as reinforcements in composites is outlined in this paper. Varying O-MMT contents in nancomposites is performed to investigate the effects on the dimensional stability (water absorption and thickness swelling) of the composites. Results indicated that increasing fiber content deteriorates dimensional stability of the composites and composites. However, improvements in dimensional stability of the keratin fibercomposites were observed with O-MMT. O-MMT treatment reduces the water absorption and thickness swelling, especially at 5wt% of O-MMT concentrationat all range of fiber content. At 5wt% concentration of O-MMt, 10wt% keratin fiber content marks the lowest water absorption and thickness swelling with rate of 0.65% and 1.93%, respectively. Adopting 10wt% of keratin fiber at 5wt% of O-MMT can be utilized for application requiring high dimensional stability.

Prediction of Mechanical Properties of Hybrid Fiber Reinforced Polymer Composites

This work presents a systematic approach to evaluate and study the effect of process parameters on tensile flexural and impact strength of coir and bagasse fiber reinforced polyester-based hybrid composites and also predicts the properties of random oriented hybrid composites. The composite panel was fabricated using hand lay-up method to the size of 300mmx200mmx3mm with various weight percentage of natural fibers namely coir (10, 20 and 30 wt %) and bagasse (10, 20 and 30 wt %) combined with polyester resin. The mechanical properties testing such as tensile, flexural and impact strength were carried out for the samples cut from the fabricated composite panel to the dimensions as per ASTM standard. The significant contribution of mixing of fiber was determined by analysis of variance. The second-order polynomial curve fitting equations are modelled to predict the mechanical properties such as tensile, flexural and impact strength. Also scanning electron microscopy testing was conducted on tensile test specimen to

Tensile, Flexural, and Compressive Properties of Coir/Silk Fiber-reinforced Hybrid Composites

The hybrid composites of coir/silk unsaturated polyester-based hybrid composites with different fiber lengths were prepared. Coir-silk fibers are taken in the ratio of 1 : 1, and these fibers are incorporated with unsaturated polyester resin with different fiber lengths like 1, 2, and 3 cm. The variation of mechanical properties such as tensile strength, flexural strength, and compressive strength of these composites with different fiber lengths has been studied. In the present work hand lay-up method was used for making the composites. Coir fibers are treated with NaOH and the effect of alkali treatment on the tensile, flexural, and compressive properties of the coir/silk hybrid composites has also been studied. Significant improvement in tensile, flexural, and compressive strengths of the coir/silk hybrid composites has been observed by these treatments.

Effect of moisture absorption on the mechanical properties of randomly oriented natural fibers/polyester hybrid composite

In this work, the variation of mechanical properties such as tensile, flexural, and impact strengths of roselle and sisal fibers hybrid polyester composite at dry and wet conditions were studied. The composites of roselle/sisal polyester-based hybrid composites with different weight% of fibers were prepared. Roselle and sisal fibers at a ratio of 1:1 had been incorporated in unsaturated polyester resin at various fiber lengths. When the fiber content and length of the roselle and sisal fibers were increased, the tensile and flexural strength of the composite increased. When the samples were subjected to moisture environment, decrease in tensile and flexural strength was observed. The maximum percentage of strength reductions in tensile and flexural strength were observed for the composites having the fiber length of 150 mm and 30 wt% fiber content. For impact strength, it was with the composites of 20 wt% and 150 mm at wet conditions compared to dry conditions. The percentage of strength reductions increased with fiber content and length in wet conditions. A scatter in the impact strength values was identified on both the conditions. The moisture absorption characteristics of the natural fibers are very important to produce the natural fiber hybrid composite materials with the positive hybrid effect. The experimental results are compared with theoretical and empirical or statistical results and found to be in good agreement.

Chemical Resistance Studies of Silk/Sisal Fiber-Reinforced Unsaturated Polyester-Based Hybrid Composites

The natural fiber environmental friendly composites of untreated and alkali treated silk-sisal unsaturated polyester-based hybrid composites were prepared by using hand lay-up technique. The fiber length was taken as 2 cm and the sisal fibers were treated with 2% NaOH. The chemical resistance of the treated and untreated silk/sisal hybrid composites to various acids, alkalis, and solvents was studied. The chemical resistance tests of these hybrid composites were performed in order to find out whether these composites can be used for manufacturing products that are resistant to chemicals.

Flexural, Compressive, and Interlaminar Shear Strength Properties of Kapok/Glass Composites

The unsaturated polyester-based hybrid composites were developed by combining the kapok and glass fabrics into polyester matrix. This study describes the flexural, compressive, and interlaminar shear resistance properties of kapok/glass polyester composites with and without alkali treatment of fabrics. These properties increase with increasing glass fabric content in composite. The mechanical performance of kapok/glass composites is excellent. The kapok/glass hybrid composites exhibited higher flexural and compressive values than sisal/glass and kapok/sisal composites.

Tensile, Flexural and Compressive Properties of Sisal/Silk Hybrid Composites

The natural fiber composites of sisal/silk unsaturated polyester based hybrid composites with different fiber lengths were prepared. Sisal—silk fiber at a ratio of 1 : 1 has been incorporated with unsaturated polyester resin with different fiber lengths such as 1, 2, and 3 cm. The variation of mechanical properties such as tensile, flexural, and compressive strengths of these composites with different fiber lengths has been studied. In the present work a hand lay-up method was used for making the composites. Sisal fibers are treated with NaOH and the effect of alkali treatment on the tensile, flexural, and compressive properties of the sisal/silk hybrid composites has also been studied. Significant improvement in tensile, flexural, and compressive strengths of the sisal/silk hybrid composites has been observed by these treatments.