PENGARUH JENIS MATRIKS TERHADAP SIFAT MEKANIS DAN FISIS KOMPOSIT HIBRID BERPENGUAT KENAF/SiO2
Abstract
The composite fiber-reinforced kenaf (Hibiscus Cannabinus) has been developed mainly in the automotive industry. Kenaf fiber has better mechanical properties than most other natural fibers such as sisal, cotton, jute, and flax. However, composites with natural fibers as reinforcement tend to have lower mechanical properties than composites reinforced with synthetic fibers. So it is necessary to modify natural fiber composites such as by adding particles and selecting the right matrix to improve mechanical properties. The purpose of this study was to determine the effect of matrix types on the mechanical and physical properties of kenaf/SiO2 hybrid composites.
In this study, the fiber used was kenaf fiber with an alkaline treatment of 6% NaOH for 36 hours. The fiber length used is ± 5 mm, and the volume fraction matrix/kenaf/SiO2 is 70:28:2. Variations in the types of matrices used were epoxy, polyester 157, and polyester 268, which were fabricated using the hot press molding method at a temperature of 100ºC for 25-50 minutes. Mechanical tests carried out are impact and bending tests, each of which refers to ASTM D6110 and ASTM D790. While the physical tests carried out are water absorption, which refers to ASTM D570 with 216 hours of immersion and measurements are carried out every 12 hours. The fracture results of impact testing were characterized using optical microscopy and scanning electron microscopy (SEM). The results showed the highest impact toughness was obtained from kenaf/SiO2/epoxy hybrid composite being 7.49 kJ/m2. The highest flexural strength and modulus were shown in hybrid kenaf/SiO2 composites with a polyester 157 matrix of 79.08 MPa and 6.24 GPa, respectively. Kenaf/SiO2 hybrid composites with polyester matrix 157 have the lowest water absorption, namely weight gain of 7.36%.