IHJPAS. 36(1)2023 139 This work is licensed under a Creative Commons Attribution 4.0 International License Improving the Mechanical Properties of Epoxy by Adding Sub-micron Cantaloupe Peel Fibers . Abstract The use of bio-fruit waste has more attention in recent years because of the low cost of bio- fibers and the protection of the environment. In this study, the epoxy was reinforced with fruit residues (cantaloupe peel powder) in proportions (1%, 2%, 3%, 4%, 5%, 7.5%, and 10% by weight) as results of mechanical tests such as impact, hardness, flexural and compression. Adding sub microns particle size cantaloupe peels particles with a weight ratio of 7.5% improves the epoxy mechanical properties, like impact strength, hardness, flexural strength, and compression strength by 59.43%, 5.8%, 45.7%, and 118.2%, respectively. Using X-ray diffraction, the crystallite size ( D) of cantaloupe peel the powder was about (3 nm). In this research, Scanning electron microscopy was used to examine the morphology of the (epoxy/7.5 % cantaloupe peel powder) composite and to interpret the improvement in epoxy mechanical properties. Keywords: epoxy, impact strength, compression strength, cantaloupe peel fibers 1.Introduction The use of agricultural waste as reinforcement in polymer instead of synthetic reinforcements has been increased. This is because natural fibers are environmentally friendly, non-toxicity, and have a low cost with lighter weight [1]. Cellulose is considered one of the best cheap materials due to its natural availability, so that it can be used as an alternative to the expensive materials of petroleum origin. Cellulose can be obtained either from a vegetarian or animal source and, generally, has excellent mechanical properties, such as tensile and bending strength. There are materials other than cellulose in plants, like pectin, Lignin, hemicellulose, and ash [2- 3]. Doi.org/ 10.30526/36.1.2910 Article history: Received 26 June 2022, Accepted 21 Augest 2022, Published in January 2023. Ibn Al-Haitham Journal for Pure and Applied Sciences Journal homepage: jih.uobaghdad.edu.iq Rand B. Lutfi Department of Phesics , College of Education for Pure Sciences, Ibn Al – Haitham, University of Baghdad, Baghdad, Iraq. rand.bassem1104a@ihcoedu.uobaghdad.edu.iq Widad H. Jassim Department of Phesics , College of Education for Pure Sciences, Ibn Al – Haitham, University of Baghdad, Baghdad, Iraq. widad.h.j@ihcoedu.uobaghdad.edu.iq https://creativecommons.org/licenses/by/4.0/ mailto:rand.bassem1104a@ihcoedu.uobaghdad.edu.iq mailto:widad.h.j@ihcoedu.uobaghdad.edu.iq IHJPAS. 36(1)2023 140 In (2020), H K Hameed et al. reinforced the epoxy with orange peel fibers with percentages (5%,10%,15%, and 20 %). The results showed that adding (15 percent by weight) orange peel and carbonized orange peel particles to epoxy increased tensile strength. In comparison, the addition value (10 percent by weight) is sufficient for improving other mechanical properties [4]. In 2021, Tuan Anh Nguyen et al. utilized banana fibers that had been processed with 5% NaOH. Mechanical and thermal properties of banana fiber-reinforced epoxy resin with weight percent (10, 15, 20, and 25 %) were studied, and the improvement in both mechanical properties and thermal stability of epoxy was achieved using the weight ratio of 20% of banana fibers [5]. Melon fruit can be created in large amounts during industrial processing, posing a severe challenge in terms of environmental effects. On the other hand, these wastes are a rich source of bioactive chemicals and nutrients that have been shown to benefit human health, so (Fátima A. Miller et al.) 2021 used cantaloupe melon peel paste in packaging food additive as antibacterial material [6]. In this research, the sub-microns of cantaloupe peel fibers were used to improve the epoxy mechanical properties like (impact strength, flexural strength, hardness, and compressive strength) by adding these fibers in different weight fractions ( 1, 2, 3, 4, 5,7.5, and 10%). 2.Materials and Methods 2.1. Preparation of Composites Cantaloupe peel wastes were dried in the sun for ten days and in the oven at 60 oCfor 7 hours; then, dried cantaloupe peels were milled using the device (NQM -0.4 ball mill), as shown in figures (1). Milling took about 60 minutes to get the sub microfibers with average particle size (~ 0.3 𝜇𝑚). Figure 1: a) cantaloupe fruits b) dried cantaloupe peels c) milling deviced) cantaloupe fibers The fibers were mixed with epoxy (Sikadur-52) using the hand-Lay technique; hardener was added in a ratio of (1:2) to epoxy. The mixtures were poured into greased Silicone molds prepared to wear test. Epoxy/ sub-microns cantaloupe fibers( EP / SMCaFs) composites were prepared with different weight ratios ( 1, 2, 3, 4, 5, 7.5, and 10 % ). The composites of (EP/ sMCaFs) with different weight percentages (1, 2, 3, 4, 5, 7.5, and 10 wt. %) of cantaloupe peels were prepared. IHJPAS. 36(1)2023 141 The (EP/ sMCaFs) mixtures are poured into silicone molds with (ASTM dimensions). For easy removal of composite sheets, the mixture (EP/ sMCaFs) was allowed in molds to cure for (1-3) days at room temperature. 2.2.Mechanical Tests 2.2.1. Impact Test For the Charpy impact test, the specimens are molded according to the international system (ISO-179) with dimensions (100×10× 8 mm). 2.2.2. Hardness Test For the hardness test (Shore D), the specimens are molded according to (ASTM D 785- 08). 2.2.3. Flexural Test Flexural test performed using three-point bending factory-made by the instrument model H50 KT (Tinius Olsen/uk). The dimensions of the samples are (100×10×4mm) according to (ASTM-D790). 2.2.4.Compression Test The compressibility qualities were tested using a hydraulic press. The test was done on composite resin specimens using a universal compression test machine. The compressive strain was found by dividing the change in the length of a specimen by the original length, and stress was calculated using equation (1) [7]. Stress ( σ) = 𝐹(𝑁) 𝐴(𝑚𝑚2) (1) Where F: is the force applied on the specimen. A: is the base area. 2.2.5 X-Ray Diffraction (XRD) XRD was used to determine the crystallographic structure of a substance. This technique was developed using an X-ray diffraction device (SHIMADZU Japan) (XRD600). The X-Ray wavelength was 1.54 Ao with a range of (10 - 80 degrees). 2-2-6 Microstructure Test The microstructure of (EP/ sMCaFs) composite was checked by an electronic photography using the electronic scanning instrument (Tescan) manufactured in Britain. 3.Results 3.1 Mechanical Tests IHJPAS. 36(1)2023 142 3.1.1 Impact Results Impact strength shows the extent of the ability of the material to absorb energy before it breaks after applying impact force [10]. Figure (2) shows the impact strength of (EP/ SMCaFs) composites, where the impact strength values increase from (9.12 kJ / m2 ) for pure epoxy to a maximum value (14.54 kJ / m2) with ( 7.5% SMCaFs ) content and down to value (10.57 kJ / m2) with (10 % SMCaFs ) content. This behavior of the impact strength curve is similar to that found by (Seenaa et al.) [8]. The addition of cantaloupe fibers with particle size 0.3 microns to epoxy with concentrations (5 and 7.5 wt %) improves the impact strength of the epoxy by 43.64 % and 59.43%, respectively. These proportions of fibers act as strength centers in the epoxy matrix [10]. Figure 2.Impact strength of (EP/ SMCaFs) composites 3.1.2 Hardness Results Figure (3) shows the increase in hardness by loading epoxy with SMCaFs at weight percentages ranging (from 2-7.5 %). (EP/ SMCaFs) composites at the Percentages of addition (5% and 7.5%) have higher values of hardness (81.2 and 82), respectively, compared to the hardness of neat epoxy (77.5). This is because of the excellent dispersion of SMCaFs between the chains of the epoxy matrix at these rates of additions, but at higher rates of additions (10%), the hardness values of (the EP/ SMCaFs) composite will be reduced. This may be due to the agglomeration of pumpkin particles in the epoxy matrix. 9.12 7.9 8.3 9.32 9.1 13.1 14.54 10.57 0 2 4 6 8 10 12 14 16 0 1 2 3 4 5 7.5 10 Im p a c t k J / m 2 IHJPAS. 36(1)2023 143 Figure 3. Hardness of (EP/ SMCaFs) composites 3.1.3 Flexural Results Flexural strength indicates the material's resistance to bending when an external force is applied [10]. Figure(4) shows that the flexural strength increased from (40.1MPa) for neat epoxy, reaching higher values (51.57MPa) and (58.43 MPa ) for (EP/5%SMCaFs) and (EP/7.5% SMCaFs) respectively. It reduced to value (42.85MPa) for (EP/ 10% 2.5MPF) composite, that means (5% and 7.5% SMCaFs) be a sufficient ratio to achieve good bonding between micro cantaloupe fibers and epoxy matrix. These results agreed with [9]. Figure 4. Flexural strength of (EP/ SMCaFs) composites 3.1.4 Compression Results Table (1) illustrates the compression test results of (Epoxy/ SMCaFs) composites, where the stress and strain values of samples rise as the force applied increases; these results are consistent with [11-12]. 77.5 74 80 81 81.1 81.2 82 77.4 70 72 74 76 78 80 82 84 0 1 2 3 4 5 7.5 10 h a rd n e ss 40.1 36.65 37.44 43.36 45.19 51.57 58.43 42.85 0 10 20 30 40 50 60 70 0 1 2 3 4 5 7.5 10 fl e x u r a l (M p a ) weight fraction % IHJPAS. 36(1)2023 144 Table 1. Compression stress and strain of (epoxy/ SMCaFs) composites Epoxy Epoxy\ 1% cantaloupe peels Epoxy\ 2% cantaloupe peels Epoxy\ 3% cantaloupe peels F (N ) ∆ L (m m) (σ) N/mm 2 ε f (N ) ∆ L (mm) (σ) N/m m2 ε F( N) ∆ L (mm) (σ) N/mm 2 ε F(N ) ∆ L (mm) (σ) N/mm 2 ε 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 50 0 0.0 5 6.435 8 0.0 02 50 0 0.05 6.384 0.0 02 50 0 0.04 6.32 0.0 01 500 0.09 6.078 0.0 03 10 00 1.4 12.87 16 0.0 57 10 00 0.24 12.78 8 0.0 09 10 00 0.28 12.64 0.0 11 100 0 0.33 12.15 6 0.0 13 15 00 2.1 19.50 25 0.0 85 15 00 0.48 19.15 2 0.0 19 15 00 0.51 19.96 0.0 02 150 0 0.65 18.23 4 0.0 25 16 50 2.9 21.23 82 0.1 17 20 00 0.69 25.53 6 0.0 27 20 00 0.71 25.28 1 0.0 08 200 0 0.82 24.31 2 0.0 32 25 00 0.92 31.92 0.0 37 25 00 0.91 31.60 1 0.0 35 250 0 1 30.39 1 0.0 39 30 00 1.45 38.30 4 0.0 58 30 00 1.5 37.92 1 0.0 45 300 0 1.24 36.46 9 0.0 4 33 00 1.32 41.71 4 0.0 51 Epoxy\ 4% cantaloupe peels Epoxy\5% cantaloupe peels Epoxy\7.5% cantaloupe peels Epoxy\10% cantaloupe peels F( N) ∆ L (m m) (σ) N/mm 2 ε F( N) ∆ L (mm) (σ) N/m m2 Ε F( N) ∆ L (mm (σ) N/mm 2 ε F(N ) ∆ L (mm) (σ) N/mm 2 ε 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 50 0 0.0 5 6.031 0.0 01 50 0 0.07 7.377 0.0 02 50 0 0.08 6.262 0.0 03 500 0.11 6.457 0.0 04 10 00 0.1 7 12.06 3 0.0 06 10 00 0.21 12.75 4 0.0 08 10 00 0.21 12.52 5 0.0 08 100 0 0.37 12.92 9 0.0 14 15 00 0.4 2 18.09 5 0.0 16 15 00 0.43 19.13 1 0.0 16 15 00 0.5 18.78 8 0.0 19 150 0 0.52 19.37 2 0.0 2 20 00 0.5 8 24.12 7 0.0 22 20 00 0.66 25.50 9 0.0 25 20 00 0.84 25.05 1 0.0 33 200 0 0.85 25.82 9 0.0 33 25 00 0.7 5 30.15 9 0.0 29 25 00 0.81 31.88 6 0.0 31 25 00 1.05 31.31 4 0.0 41 260 0 1.27 30.99 5 0.0 49 30 00 0.9 8 36.19 1 0.0 38 25 50 1.07 38.26 3 0.0 41 30 00 1.35 37.57 7 0.0 53 32 00 1.1 9 38.60 4 0.0 46 35 00 1.64 43.84 0.0 64 37 00 1.85 46.34 6 0.0 72 IHJPAS. 36(1)2023 145 Figure (5) shows thatcompression strength increase from (21.23Mpa ) for epoxy to higher value (46.34 Mpa)for (epoxy/7.5 % cantaloupe fibers) , which is due to the fact that (7.5 %) of cantaloupe peel is a good ratio for joining the epoxy chains and therefore improving the bearing capacity under the applied load. Figure 5.Compression strength of (EP/ SMCaFs) composites Figure (6) shows that the maximum strain value decreases from a higher level (0.117) for neat epoxy to reach its minimum value (0.04) by adding 3% of cantaloupe fibers to epoxy and increasing up to (0.072) by adding 7.5% of cantaloupe peels waste fibers. Figure 6. Compression strength of (EP/ SMCaFs) composites 3.2 X-Ray Diffraction ( XRD) Figure (7) shows the (XRD) pattern of cantaloupe peel powder, which can use to find the highest three peaks and there (𝜃) position and intensities are summarized in Table (2). 21.2382 38.304 41.714 36.469 38.604 38.263 46.346 30.995 0 5 10 15 20 25 30 35 40 45 50 0 1 2 3 4 5 7.5 10 co m p e re ss iv e s tr e n g th N /m m 2 weigth fraction % 0.117 0.058 0.051 0.04 0.046 0.041 0.072 0.049 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0 1 2 3 4 5 7.5 10 ε weight fraction % IHJPAS. 36(1)2023 146 Figure 7. XRD of cantaloupe peel fibers Table 2. The theta position, d – space, FWHM and intensity of the highest three peaks No. peak The Peak inX-ray spectrum Theta position d- space(A°) FWHM (deg) Intensities 1 6 21.37 4.15 4.8 124 2 5 18.826 4.709 0 71 3 4 16.91 5.238 0 56 To estimate the crystallite size ( D), Scherer formula (2) is used [13]. D= 𝐾 λ 𝐵𝑐𝑜𝑠 𝜃 … … … (2) Where λ: X ray wave length. K : Scherer constant , which equals to 0.94 𝜃: is the diffraction angle B: is full width at half maximum crystallite size ( D) of cantaloupe peel powder is about (3 nm ) . 3.3 Saning Electron Microscope (SEM) Figure (8) shows the morphology of the composite (epoxy/7.5 cantaloupe fibers) at various magnifications (5000 x,1000 x, and 200x ), where the dispersion of cantaloupe particles in the epoxy is good, some agglomeration cavities can also be identified. IHJPAS. 36(1)2023 147 a) 5000x b) 1000x c) 200x Figure 8. SEM images of epoxy/ sub microns cantaloupe peel fibers with magnification 4.Conclusion 1- Adding Cantaloupe peel fibers to epoxy greatly improves its mechanical properties. 2- The best value of cantaloupe peel fibers that make epoxy can be used as natural gelcoats 7.5%. 3-From the X-ray diffraction spectrum, cantaloupe peel fibers' crystallite size (D) can be determined. 4- SEM images of (epoxy/7.5% SMCaFs)) composite shows its morphology, which supports and explains the improvement in the mechanical properties. References 1. Parbin, S.; Waghmare ;N. K., Singh ;S. K., ; Khan, S.;Mechanical properties of natural fiber reinforced epoxy composites: A review,Procedia Computer Science,2019, 152, 375- 379. 2.Kumar; A., ; Srivastava, A. Preparation and mechanical properties of jute fiber reinforced epoxy composites. Industrial Engineering and Management, 2017, 6, 1-4. 3. Niharika Mohanta; Achyarya, S.K. Mechanical and Tribological Performance of LuffacylindricaFibre-Reinforced Epoxy Composite, Science of technology,2015, 7, 1, 1- 10 4. Hameed, H. K.;Jassim, W. H. Comparison Study of Some Mechanical Properties of Epoxy Composites usinguncarbonized Orange peel and Carbonized Orange peel, : Materials Science and Engineering 2020. 5.Anh Tuan Nguyen;ThiHuong Nguyen;Banana Fiber-Reinforced Epoxy Composites: Mechanical Properties and Fire Retardancy, International Journal of Chemical Engineering 2021. 6.Fátima, A.; Miller; Joana, F. Fundo ; Ester Garcia; Cristina L. M. Silva ; Teresa R. S. Brandão , Effect of Gaseous Ozone Process on Cantaloupe Melon Peel: Assessment of Quality and Antilisterial Indicators,foods,2021. 7. Balqees M Dheyaa1 ;Widad H. Jassim; Noor A. Hameed,Evaluation of the Epoxy/Antimony Trioxide Nano composites as Flame Retardant, Journal of Physics,,2018, 1003, 15. https://www.researchgate.net/profile/Anh-Nguyen-301 https://www.researchgate.net/scientific-contributions/Thi-Huong-Nguyen-2198628754 https://www.researchgate.net/journal/International-Journal-of-Chemical-Engineering-1687-8078 IHJPAS. 36(1)2023 148 8.Seenaa I. Hussein ;Alaa M. Abd-Elnaiem;Tesleem B. Asafa;Harith I. Jaafar; Effect of incorporation of conductive fillers on mechanical properties and thermal conductivity of epoxy resin composite , Applied physics , 2018 . 9.Shatha H. Mahdi; Widad H. Jassim ,Intisar A.Hamad; Kareem A. Jasim, Epoxy/Silicone Rubber Blends for Voltage Insulators and Capacitors Applications Environment and Sustainability, Science Direct,2017, 119, 501-506. 10. Diana L; Ortiz-Barajas ; Johan A. Arévalo-Prada ; Octavio Fenollar ,;Yesid J. Rueda-Ordonez and Sergio Torres-Giner ; Torre faction of Coffee Husk Flour for the plat coffeDevelopment of Injection-Molded Green Composite Pieces of Polylactide with High Sustainability ,Applied Science ,2020, 10. 11.Watan, A. W. Possibility of Reducing the Thermal Conductivity of Ceramic Refractory Materials , Ibn AL- Haitham Journal For Pure and Applied Sciences,2012, 3, 25 , 195. 12.Widad H. Jassim ,preparation of the epoxy chicken eggshell composites to use in surface coating, Ibn AL- Haitham Journal For Pure and Applied Sciences,2017, 29 . 1. 13. Toibah, A.R.; Misran, F. ; Mustafa, Z. ; Shaaban. A. Calcium Phosphate from Waste Animal Bones: Phase Identification Analysis CALCIUM PHOSPHATE FROM WASTE ANIMAL BONES: PHASE IDENTIFICATION ANALYSIS, Journal of Advanced Manufacturing Technology,2018. https://www.researchgate.net/scientific-contributions/F-Misran-2152061068 https://www.researchgate.net/profile/Zaleha-Mustafa https://www.researchgate.net/scientific-contributions/A-Shaaban-2139815190 3. Niharika Mohanta; Achyarya, S.K. Mechanical and Tribological Performance of LuffacylindricaFibre-Reinforced Epoxy Composite, Science of technology,2015, 7, 1, 1- 10 9.Shatha H. Mahdi; Widad H. Jassim ,Intisar A.Hamad; Kareem A. Jasim, Epoxy/Silicone Rubber Blends for Voltage Insulators and Capacitors Applications Environment and Sustainability, Science Direct,2017, 119, 501-506. 13. Toibah, A.R.; Misran, F. ; Mustafa, Z. ; Shaaban. A. Calcium Phosphate from Waste Animal Bones: Phase Identification Analysis CALCIUM PHOSPHATE FROM WASTE ANIMAL BONES: PHASE IDENTIFICATION ANALYSIS, Journal of Advanced Manufacturing Technology,2018.