PSI - Issue 27

Sakuri Sakuri et al. / Procedia Structural Integrity 27 (2020) 85–92 Sakuri et al. / Structural Integrity Procedia 00 (2019) 000 – 000

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3.3. Interfacial shear strength (IFSS) testing Interfacial shear strength testing (IFSS) was conducted by attaching 60 mm cantala fiber to an unsaturated polyester mixture, microcrystalline cellulose, and Methyl Ethyl Ketone Peroxide (MEKPO) catalyst. Cantala fibers were glued to cardboard with a hole in the middle and dried for 120 minutes. The clamping distance was 50 mm with a pull speed of 250 mm/minute, and 30 repetitions are performed. Paper from both sides was cut to get a maximum pull. The fiber is pulled until the bond between UPRs + MCC breaks (see illustration in Fig. 3). The calculation of the test was based on the release of fibers from the matrix. Fiber diameter was measured on the top, middle, and bottom sides. Experiments are performed using the Tenso Model 300 type 168 E Newton Unit textile pulling machine at the Textile Laboratory of the Islamic University of Indonesia (Yogyakarta, Indonesia). The IFSS test results are shown in Fig. 4.

Fiber

UPRs + MCC

Hole

Fig. 3. Specimen design for interfacial share strength test.

3.67

3.19

2.94

2.92 2.82

2.49

Shear strength (MPa)

UE AI 3 AI 6 AI 9 AI 12 AI 15

Fig. 4. Results of the interfacial bonding CF.

The results of this study are based more on the strength of the fiber to escape the bonding of UPRs matrix and microcrystalline cellulose reinforcement mixture. Increased adhesion due to increased surface roughness on CF. Fibers undergoing alkali treatment show fibers that are cleaner and an increase in surface roughness, which indicates fibers have more bonding with the matrix. UE fibers show an interfacial bonding value of 2.49 MPa slightly higher than the results of the previous study (Raharjo et al., 2017) of 2.45 MPa. Fiber with an alkaline AI 3 treatment showed an increase in interfacial bonding by 2.94 MPa. The highest shear strength was obtained by immersion treatment up to 6 h (AI 6) of 3.67 MPa. On the other hand, more extended treatment of alkali fibers breaks down hydroxyl bonds, thus showing a decrease in the bond between the fiber face and the matrix.