Effects of Alkali (NaOH) Treatment of Banana Bunch Fiber (Musa Paradisiaca) on the Tensile Properties of Banana Bunch Fiber/Unsaturated Polyester Composites


  • M. Iqbal Pratama Universitas Mataram
  • Sugiman Sugiman Universitas Mataram
  • Agus Dwi Catur Universitas Mataram
  • Ahmad Hilton Universiti Tun Hussein Onn Malaysia




Banana bunch, Fiber, Alkali, Composites, Tensile strength


The increase in environmental awareness worldwide has driven the design of environmentally friendly materials. The detrimental environmental impact has shifted attention from synthetic fibers to natural fibers. Natural fiber composites have attracted the attention of material engineers due to their ability to decompose, abundant and sustainable availability, low density, and high specific strength. Many sources of natural fibers have been used for composite reinforcement, such as jute, kenaf, sisal, coconut fiber, pineapple fiber, and banana stem fiber. Fibre treatment is necessary to enhance the compatibility between polymer matrix and natural fibers. The most commonly used method is alkali treatment using a sodium hydroxide (NaOH) solution. This research investigates the effect of alkali concentration (NaOH) on the properties of unsaturated polyester reinforced with Kepok banana (Musa paradisiaca) bunch fiber. Banana bunch fibers were treated with alkali solutions at concentrations of 2, 4, 6, and 8% for 2 hours. The fiber content in the matrix was 40%. The tests that were conducted included Fourier Transform Infrared (FTIR) spectroscopy, X-ray diffraction (XRD), tensile testing, and scanning electron microscopy (SEM). It was found that alkali treatment improved the tensile strength and elastic modulus of unsaturated polyester/banana bunch fiber composites. The 2% alkali treatment provided the highest tensile strength and elastic modulus, increasing by 92.13% and 273%, respectively. The optimal results of the 2% alkali treatment were confirmed by FTIR, XRD, and SEM analysis.


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