The Effect of Epoxy-Polyester Matrix Mixture on Prasok Leaf Fiber-Reinforced Composites on Bending Strength and Morphology.

Abstract

This study aims to evaluate the effect of the composition of the epoxy-polyester matrix mixture with praksok leaf fiber
reinforcement (Cordyline australis) in biocomposites on the bending strength and morphology ofbiocomposites. Experimental
methods were used to make biocomposites. Praksok leaf fibers thathad been soaked in 5% NaOH for 2 hours and a mixture of
epoxy-polyester resin were used as reinforcing materials in making composites with a mixture of epoxy and hardener 2:1.
Variation of the volume composition of the matrix and fiber (85% matrix: 15% fiber). The specimens were molded using acrylic
molds with the hand lay-up technique. The size of the specimens is based on ASTM D790 -03 for bending strength tests,
morphology tests using (Scanning Electron Microscope) SEM. The bending test data shows that the highest bending stress is
found in the composite specimen with a mixture of 95% epoxy: 5% polyester with an average stress value of 76.8114 Mpa, in
the variation of 90% epoxy: 10% polyester the average value is 56.18562 Mpa, while the smallest is in the variation of 85%
epoxy: 15% polyester with an average value of 24.944 Mpa, The largest strain occurs in the specimen with a mixture of 85%
epoxy: 15% polyester of 10.0444, andthe smallest occurs in the variation of 95% epoxy: 5% polyester of 5.1238. For the large st
modulus of elasticity comes from the variation of the mixture of 95% epoxy: 5% polyester, which is 1.4964 Gpa, while the
smallest is in the variation of 85% epoxy: 15 polyester with a value of 0.2706 Gpa. In the test that has been carried out, the
variation of 95% epoxy: 5% polyester has the highest bending strength, this is due to the creation of better cross -linking
between the matrix mixture and fibers that have been soaked in NaOH, where this is also supported by morphological tests
using SEM (Scanning Electron Microscopy) which shows the bonds in the composite