TENSILE PROPERTIES AND INTERFACE SHEAR STRESS OF IMPERATA CYLINDRICA (L) BEAUV FIBER EXPOSED TO ULTRA VIOLET RAY

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1 International Journal of Mechanical Engineering and Technology (IJMET) Volume 9, Issue 9, September 2018, pp , Article ID: IJMET_09_09_126 Available online at ISSN Print: and ISSN Online: IAEME Publication Scopus Indexed TENSILE PROPERTIES AND INTERFACE SHEAR STRESS OF IMPERATA CYLINDRICA (L) BEAUV FIBER EXPOSED TO ULTRA VIOLET RAY Benyamin Tangaran Mechanical Engineering Department, Paulus Christian University of Indonesia Rudy Soenoko, Yudy Surya Irawan and Anindito Purnowidodo Brawijaya University, Mechanical Engineering Department, Engineering Faculty, 65145, Malang Indonesia ABSTRACT This study reveals the tensile strength and IFSS of a single fiber Imperata cylindrica (L) Beauv treated by a ultraviolet light exposure process. This plant is a wild plant and rapidly proliferating plant. It has been traditionally used by people for house roofs and goods binder. This study aims to determine the tensile strength and IFSS of the material in accordance with the desired application. The fiber was treated by given an ultraviolet ray exposure for 20 hours, 50 hours and 100 hours. From the test results it is obtained a single fiber tensile strength of MPa for a fiber treated with UV ray for 50 hours. The IFSS and shear stress on fiber with 50 hours ultraviolet ray exposure is N / mm 2. Keywords: Imperata cylindrica, Ultraviolet ray, Single fiber. Cite this Article: Benyamin Tangaran, Rudy Soenoko, Yudy Surya Irawan and Anindito Purnowidodo, Tensile Properties and Interface Shear Stress of Imperata Cylindrica (L) Beauv Fiber Exposed to Ultra Violet Ray, International Journal of Mechanical Engineering and Technology, 9(9), 2018, pp INTRODUCTION With the rapid technology advances today, the research was also developed in all fields, whether it is a new discovery or a development of existing ones. One of them is the fiberbased composites, both for binder matrix variations or fiber as a reinforcing material. For example a mat type for the basic matrix and fiber materials. Research has also evolved with the use of natural fibers for some variations of synthetic and natural matrices. Natural fiber composites are increasingly being developed in relation to its use in various fields of life and demanding the use of inexpensive, easily available, light weight, strong mechanical editor@iaeme.com

2 Tensile Properties and Interface Shear Stress of Imperata Cylindrica (L) Beauv Fiber Exposed to Ultra Violet Ray properties, corrosion resistance and environmentally friendly material. So it can become an alternative material other than metal. [1-3]. A research on the analysis of the mechanical properties of the epoxy composite with palm tree fiber as the strengthener resulted from an indication that the random angular orientation affects the composite tensile strength and impact resistance value. Another research about hemp natural fiber (Boehmeria nivea) found that a surface treatment would influence the fiber wettability and the epoxy resin matrix adhesion ability. Based on the previous research done above, it is necessary to examine the use of fiber Imperata cylindrica (L) Beauv treated exposed by ultraviolet (UV) as reinforcement in composite epoxy. The research would emphasize to determine the Imperata cylindrica (L) Beauv fiber exposed to UV ray tensile strength so that it can be used in accordance with the desired application. Composites are defined as structures in the macro or micro scale which is made from different materials, the material character was still carried away after the component is fully formed. The reason for choosing natural fibers as reinforcement composite according to some researchers, among others: (1) natural fiber composites are environmentally friendly, have excellent mechanical properties (can compete with synthetic fibers), relatively cheap; (2) the natural fibers density are smaller in the range of 1.25 to 1.5 g/cm 3 compared to E- glass (2.54 g/cm 3 ) and Carbon fiber (1.8 to 2.1 g/cm 3 ), [5]. Therefore, according [5], the natural fiber is much lighter so that the energy consumption to produce this kind of composite is smaller. Besides the natural fibers are renewable and is always available. These reasons are encouraging the development of engineering research in the composite materials field, both existing and new. To form a composite, there are three main requirements that must be met, the first requirement is that a composite should consist of two materials or more that have different properties. Second, have a strong bond between the matrix and fiber. Third, merging the different materials would generate a new material that has a different property from the base materials. Imperata cylindrica (L) Beauv is a wild plant that would be an agriculture annoyed because it is easy and quick to breed. Imperata cylindrica (L) Beauv, has been used as house roofs and use as goods binders. That is why, one of the efforts to increase the Imperata cylindrica (L) Beauv utility, is through this research that is utilizing fiber Imperata cylindrica (L) Beauv as the composite raw material. It is expected to be used in various fields of application. Some reasons to choose Imperata cylindrica (L) Beauv fiber as a composite material is economically valuable, easily obtained in large quantities, an unused material, environmentally friendly and is a non-corrosive material. The Imperata cylindrica (L) Beauv were composed of lignin, cellulose, and hemicellulose. Lignin is associated with cellulose in providing cell stiffness. Lignin serves as an adhesive to bind one cell to another. Hemicellulose, cellulose, and pectin are a number of carbohydrate compounds contained in holocellulose [3-5]. A big size holocellulose would give better fiber strength. The Imperata Cylindrica as a new natural fiber was introduced by Srinivasababu. The fiber was extracted with a breaking method. The fiber was inserted in polyester as the matrix reinforcement. The composite was produced by using a lay-up technique to make a tensile specimen, bending specimen, impact specimen according to ASTM procedures. The highest tensile strength value is MPa, with a modulus elasticity of MPa was observed for Cylindrica Imperata fiber reinforced on polyester composite at a maximum volume fraction with fiber chemically treated. At a 14.75%, 35.89% Imperata Cylindrica fiber volume fraction composite it is shown that the bending strength is about MPa, and modulus elasticity of 4.81 GPa. The impact strength of kj/m 2 was obtained for composites reinforced with 34.73% Imperata Cylindrica fiber on a volume fraction [6] editor@iaeme.com

3 Benyamin Tangaran, Rudy Soenoko, Yudy Surya Irawan and Anindito Purnowidodo Ultraviolet is a part of the electromagnetic spectrum and does not need a medium to propagate. Ultraviolet has a wavelength range between nm which is located between the spectrum of X-rays and visible light (EPA, 1999). In general, ultraviolet sources can be obtained for natural and artificial with the sun as the main source of ultraviolet in nature. Artificial ultraviolet sources usually came from a special fluorescent lamp, such as lowpressure mercury lamp and medium pressure mercury lamp. Medium pressure mercury lamp is able to produce ultraviolet radiation output which is greater than the low-pressure mercury lamp. However, the low-pressure mercury lamp is more efficient in power consumption compared to a medium pressure mercury lamp. Low-pressure mercury lamps produce a maximum radiation at a wavelength of nm which is lethal for microorganisms, protozoa, viruses and algae. While the medium pressure mercury lamp radiation is emitted at a wavelength of nm [7, 8, 9, 10]. Research conducted by Ramli [4] is trying to find out a fundamental understanding of the UV exposure effects on fiber. The effects of UV exposure on fiber physical and mechanical properties for the application of manufacturing bulletproof vest, which discusses the ability of UV light to turn material to be hardened. In this study UV light exposure is used to determine the physical fiber composite material behavior with a certain exposure that could increase the fiber strength. The ultraviolet light exposure followed by cooling on the strengthening of carbon fiber composites with epoxy would cause a degradation that can reduce the physical properties of quantum mechanics on a special exposure to the carbon fiber composite material [11]. In the use of natural fibers for composites many factors could influence the composite quality, such as the environmental conditions, temperature, ultraviolet radiation and mechanical fatigue. Imperata cylindrical lignin consists of 31.27%, 40.22% alpha cellulose, 18.40% hemicellulose and 9.09% pectin [12]. Ultraviolet radiation and visible light is absorbed by the aromatic organic molecules, which is the molecules containing the π- conjugated electron and atom-containing electron-n. This condition would cause the transition of electrons in the outer orbital exited electron energy levels to be higher. The amount of radiation absorbed is proportional to the amount of analytic molecules that absorb, so it can be used for quantitative analysis. Ultraviolet light absorption molecules containing other elements that lead to the degradation of lignin element which is partially lifted and the fiber surface becomes rougher [13]. Based on this description, the ultraviolet rays will be used for the fiber treatment process to determine the effect of ultraviolet light exposure. 2. EXPERIMENTAL SETUP The material used in this study is the fiber Imperata cylindrica (L) Beauv which grew out of the Tana Toraja area. Fiber Imperata cylindrica (L) Beauv dried naturally under the sun ray heat. The fiber was cut into 10 cm pieces long and was further placed between two fluorescent tube lamps which emit the light purple (ultraviolet) in a certain box. The fiber amount exposure with ultraviolet ray is about 400 grams. The fiber treatment duration time is 20 hours, 50 hours and 100 hours. Every fiber treated was taken as much as 130 grams for each test sample. The treated single fiber Imperata cylindrica (L) Beauv, was then test to determine the fiber tensile strength. The tensile test was done using a single fiber pull LR10K testing machine with a capacity of 10 kn under an ASTM standard. The tensile test specimen sample is 30 mm long and the fiber diameter was measured using a digital microscope. Three specimens was taken from every test set to be measured and the tensile strength of each specimen is recorded and can be seen visually on the screen monitor. The SEM-EDS testing is to observe the fiber surface topography, fiber composition (an element constituent fiber mixture) and the fibers morphology editor@iaeme.com

4 Tensile Properties and Interface Shear Stress of Imperata Cylindrica (L) Beauv Fiber Exposed to Ultra Violet Ray From the single fiber pull-out test it is expected an information about the direct interaction between the fiber-matrix interface areas that could indicate the composite transfer stress, where the higher the value it will generate the high interface shear strength [7,8]. Figure 1 shows the pull out test procedure of a single fiber embedded in the matrix with a depth of lo and subjected to an axial load of P. Load P is expected to repeal of the fibers which is embedded in the matrix and assumed that the shear stress along the fiber surface is uniform and an equilibrium force occurs. The shear stress that occurs between fiber and matrix is shown in Figure 1. Figure 1 Single fiber pull out mechanism 3. RESULTS AND DISCUSSIONS Figure 2 shows the single fiber tensile test result. The single fiber tensile strength rises until the highest value which is under the 50 hours UV treatment time with a tensile strength of Mpa. Based on the research conducted by Renreng [16] about Akaa fibers with turmeric water immersion for one hour, it can increase the Si, Al and Na elements percentage that absolutely increase the fiber strength. From the EDS testing, as shown in Figure 3, there is a silicon element (SiO 2 ) but there is no significant change and an increased of Aluminum element (Al2O 3 ) under the 50 hours ultraviolet exposure treatment. This is the indication that the fiber strength could increase with the increase of aluminum elements. On the untreated single fiber specimen, the tensile strength is about MPa as seen in Figure 2. The test result of the observations is as follows: Figure 2 Single Fiber Tensile Strength editor@iaeme.com

5 Benyamin Tangaran, Rudy Soenoko, Yudy Surya Irawan and Anindito Purnowidodo Figure 3 Element on the imperata cylindrica (L.) Beauv fiber, EDS result Figure 4 Shear Stress Figure 4 shows the pull-out test results. This result is the shear stress obtained for each treatment. On the 20 hours UV ray exposure treatment there is a shear stress decline compared with the pull out shear stress for the untreated fiber. The highest shear stress is obtained in the 50 hours UV rays exposure, amounted to N/mm 2 and on the 100 hours UV exposure treatment the shear stress result is as big as N/mm2. The shear strength increased occurs due to the fiber rough surface and grooved which causes the fiber epoxy matrix shear transfer efficiency to be better [17]. The test results showed an increase in surface roughness of 1.47 μm on 50 hours UV treatment, shown in Fig editor@iaeme.com

6 Tensile Properties and Interface Shear Stress of Imperata Cylindrica (L) Beauv Fiber Exposed to Ultra Violet Ray Figure 5 Surface Roughness In Fig 6 consecutive pull-out test of a single fiber up to taken off by observing the different epoxy matrix surface conditions. Figure 6a is a result for fiber with the UV treatment and Figure 6b - d is the fiber with UV treatment under a different duration time. From Figure 5a it is seen that the fiber surface looks smooth and in Figure 6b - d it is seen that the fiber surface began to disintegrate, irregular and rough. Figure 6 The matrix and fiber interface SEM result (a) Fiber without treatment, (b) Fiber with 20 hours UV treatment, (c) Fiber with 20 hours UV treatment (d) Fiber with 100 hours UV treatment editor@iaeme.com

7 Benyamin Tangaran, Rudy Soenoko, Yudy Surya Irawan and Anindito Purnowidodo Figure 7 Imperata Cylindrica fiber and epoxy matrix interface interlocking SEM result (a) Without treatment, (b) 20 hours UV treatment, (c) 50 hours UV treatment, (d) 100 hours UV treatment. Figure 7 shows the gap between epoxy matrix (arrow one) and fibers Imperata Cylindrica (arrow two). The matrix surface associated with the Imperata cylindrica fiber interface interlock with the epoxy matrix seen has a large gap (arrow three) as shown that the interlocking is not quit well. Because there is still lignin elements that make the fiber surface become smooth[18]. Fiber treated for 20 hours duration time exposure to ultraviolet rays is seen in figure 6b (arrow four). It is clearly showing that the gap between the matrix and fiber is smaller, so that the fiber surface starts to be a bit rougher which result a better interlock. Figure 6c (arrow five) shows a perfect interlock as a result of fiber exposed to ultraviolet rays that would damage the lignin on the fiber surface and would increase a perfect adhesion. A large fiber surface damage due to ultraviolet light exposure is shown in Figure 6d (arrow six) which would lower the pull out shear stress. Figure 7 shows the gap between epoxy matrix (arrow one) and fibers Imperata Cylindrica (arrow two). The matrix surface associated with the Imperata cylindrica fiber interface interlock with the epoxy matrix seen has a large gap (arrow three) as shown that the interlocking is not quit well. Because there is still lignin elements that make the fiber surface become smooth[18]. Fiber treated for 20 hours duration time exposure to ultraviolet rays is seen in figure 6b (arrow four). It is clearly showing that the gap between the matrix and fiber is smaller, so that the fiber surface starts to be a bit rougher which result a better interlock. Figure 6c (arrow five) shows a perfect interlock as a result of fiber exposed to ultraviolet rays that would damage the lignin on the fiber surface and would increase a perfect adhesion. A large fiber surface damage due to ultraviolet light exposure is shown in Figure 6d (arrow six) which would lower the pull out shear stress editor@iaeme.com

8 Tensile Properties and Interface Shear Stress of Imperata Cylindrica (L) Beauv Fiber Exposed to Ultra Violet Ray 4. CONCLUSION Based on the research that has been done, it can be concluded that the fiber Imperata Cylindrica (L.) Beauv treated with ultraviolet can be used as reinforcement in composites: 1. Ultraviolet could change the Imperata cylindrica (L.) Beauv, the fiber surface morphology shape is being rougher and pores are formed on the fiber surface to be filled by the resin. 2. Fiber Imperata Cylindrica (L.) Beauv., which is treated with ultraviolet rays with a 50 hours duration time increase their tensile strength. 3. The shear stress between the matrix and the fibers exposed to ultraviolet light. 4. From the SEM testing result it could be seen, that there are changes on the fiber surface that would allow the resin get into the fiber pores which is formed due to the ultraviolet treatment. REFERENCES [1] MN Belgacem, A Gandini, The Surface Modification of Cellulose fibers for Use as Reinforcing in Composite materials, Composite interfaces; 2005; [2] JM Berthelot, Composite Materials: Mechanical Behavior and Structural Analysis, pen Springer-Verlag, New York; [3] B Kurnatowski, A Matzenmiler, Coupled Twoscale Analysis of-fiber Reinforced composite Structures with microscopic damage evolution, International Journal of Solids and Structures; [4] J Ramli, Effects of Photoinitiator Addition to the Mechanical and Physical Properties of the Epoxy and Vinyl Ester Fiber Glass Laminated Composites, International journal of Applied Science and Technology; 2011; 3: [5] Mallick, Fiber Reinforced Composites Materials Manufacturing and Design 3rd Ed; [6] N Srinivasababu, Imperata Clylindrica/sacrad grass long fiber reinforced polyester composites An Experimental determination of properties, Applied mechanics and materials; 2014; 612: [7] A Andre, Fibers for strengthening of timber structures, Technical report, Lulea University of Technology, Swedia. 2006; [8] LT Drzal, Chemical, Physical and Mechanical Methods of Fiber-Matrix Adhesion and Interphase Characterization in Composite, Electron Beam Curing Workshop, Oak Ridge; [9] H Alamri, IM Low, Mechanical properties and water absorption behavior of recycled cellulose fibre reinforced epoxy composites; [10] H. Alamri, IM Low, Mechanical properties and water absorption behavior of recycled cellulose fiber reinforced epoxy composites; [11] Bhavesh G Kumar, Degradation of carbon fiber-reinforced epoxy composites by ultraviolet radiation and condensation, Journal of composite materials; 2002: [12] Budi Setiya. Chemical Ingredients and Properties of Fiber Imperata Cylindrica As Raw Material Overview Pulp and Paper; 2012:8-19 [13] Emad Yousif,. Photodegradation and photostabilization of polymers especially polystyrene : review, SpringerPlus journal; [14] Drzal, L., T. ASM Handbook: composite interface, Interfaces and Interphases, FB; [15] Rider, A. Surface Properties Influencing the Fracture Toughness of aluminium-efoxy joint, Disertasi, University of New South Wales; editor@iaeme.com

9 Benyamin Tangaran, Rudy Soenoko, Yudy Surya Irawan and Anindito Purnowidodo [16] Renreng Ilyas et al. Effect of Turmeric (Curcuma) Treatment Toward the Singel Fiber Akaa (Corypha) Tensile Strength, International Journal of Applied Engginering Reseach; 2015: [17] Musa Bondaris Palungan et al. The Effect of Fumigation Toward the Engagement Ability of King Pineapple Leaf Fibre (Agave Cantula Roxb) with Epoxy Matrix; 2016; [18] Arsyad Muhammad et al. The morphology coconut fiber surface under chemical treatment; 2015;