PSI - Issue 27

Sakuri Sakuri et al. / Procedia Structural Integrity 27 (2020) 85–92 Sakuri et al. / Structural Integrity Procedia 00 (2020) 000 – 000

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1. Introduction Demand for an alternative material to be used as engineering structures leads scholars to investigate the potential of natural resource as a component of advanced material with goals to reduce the implementation of steel in various structures (Cao et al., 2016; Bae et al., 2016; Prabowo et al., 2017; 2018; 2019). The growth rate and durability of cantala is better in dry or marginal environments. Agave cantala was widely planted in the regions of Java and Sulawesi (Indonesia) and obtained its fiber by mechanical retting. The advantages of natural fibers were cheap, renewable, biodegradable, low density, and harmless. Cantala fiber (CF) has a low density, was non-abrasive during processing, and has cellulose, which can be used as a composite (Palungan et al., 2017). The high polar characteristics on natural fiber included CF to make it less compatible with weak or non-polar polar polymers (Xie et al., 2010). Various types of chemical treatments were offered to improve fiber characteristics such as alkaline, silane, peroxide, permanganate treatment (William et al., 2011; John et al., 2008). Alkaline treatments were able to make changes to the structure of the fiber by removing lignin and wax from fibrils. So naturally, there was damage to the regulation of fibrils (Aydin et al., 2010). But treatment with lye provides more effective results compared to the three treatments above (William et al., 2011). Fiber morphology methods provide information on changes in chemical topography on the fiber surface. SEM morphological analysis on the surface of the fiber provides essential information on the shape of the fiber surface due to alkali treatment. The thermal analysis method on fiber (TGA) was a technique for measuring changes in a weight loss of a sample that experiences a steady increase in temperature so that it can gauge reactions involving gases and emissions. TGA has offered more precise heating control, temperature range, and accurate variable heating rate of the observed fiber, and only a few samples were investigated. Degradation of natural fibers by thermogravimetric analysis has been widely investigated in previous studies (Rennekar et al., 2004). TGA involves heating the material to exceed the temperature of thermal degradation at a controlled level and monitoring weight loss during the heating process. Micromechanical transfer and interfacial shear strength play an important role in material characterization because the better the ability to transfer stress will produce a high shear interface (Khalil et al., 2001). Many approaches have been taken to improve the adhesion properties between matrices and fibers in composites. Surface modification of the fiber increased the surface energy and bonding of the fiber interface, thus obtaining better mechanical properties (Zazwa et al., 2013). Also, the breaking of hydrogen bonds in network structures (Li et al., 2007) increases surface roughness. It will be able to increase the interface shear strength between the matrix and the fiber, consequently increasing the matrix transfer and fiber stress. In terms of the design process, making composites and adding microcrystalline cellulose are usually conducted to increase the mechanical strength of the material. The addition of microcrystalline cellulose in composites can improve material properties and characteristics (Kiziltas et al., 2014), e.g., increase the modulus of elasticity, reduce thermal expansion, and creep strength. (Rigotti et al., 2015). The current research was still very relevant to assessing CF treatment and adding advanced material microcrystalline cellulose to the composite. 2. Experiment preparation 2.1. Material resources CF was obtained from CV Rami Jaya Kulonprogo Yogyakarta, extracted by mechanical retting, dried at room temperature. Sodium hydroxide (NaOH) of 98% purity, aquades, and ethylene glycol from PT Merck (Jakarta, Indonesia). Unsaturated Polyester (UPRs Yucalac BTQN 157 and Methyl Ethyl Ketone Peroxide from PT Justus Kimia Raya (Semarang, Indonesia). Microcrystalline cellulose with a size of 2 0 μm and a density of 1.56 gr /cm 3 from Sigma Aldrich Agent (Jakarta Indonesia). CF was soaked with sodium hydroxide (NaOH) concentration of 6% wt for 0 h (EU), 3 h (AI 3), 6 h (AI 6), 9 h (AI 9), 12 h (AI 12), and 15 h (AI 15) at room temperature. The fiber was rinsed with tap water to clean off the lye, until a pH ∽ 7 was reached. The fibers were dried at room temperature for 24 h and heated in an oven at 60 °C for 10 h.