Dielectric Behavior of OPEFB Reinforced Polycaprolactone Composites at X-Band Frequency

Abstract

Short fibres are often used as reinforcing materials with thermoplastic polymers to improve the dielectric properties of the composites. In this work, the effects of oil palm empty fruit bunch (OPEFB)-fibre loading on polycaprolactone (PCL) polymer were extensively studied. The synthesis of OPEFBPCL composites were prepared via melt blend method. Theoretical and experimental analysis of electromagnetic (EMI) propagation, absorption and shielding effectiveness (SE) properties of the composite were also studied. The magnitudes of Sparameters for OPEFB fiber-reinforced PCL composites with different percentages of filler were measured by a rectangular waveguide connected with a microwave vector network analyzer (VNA) at (8-12) GHz frequency. Whilst the dielectric properties were studied using an open ended coaxial probe. The morphological characterization of the OPEFBPCL composite was carried out using X-ray diffraction and scanning electron microscopy (SEM). This work showed that XRD profile patterns slightly changed duo to the filler loading increment which result a reduction in both dielectric constant and loss factor. However, the relative permittivity of pure oil palm fibre and PCL was measured as (1.8-j*0.08) and (2.929j*0.3242) respectively. In addition, the composition of 12.5 wt% filler gave the highest dielectric constant and loss factor values. However, the reflection loss increases to filler content increments at the maximum frequency of 12 GHz-The excellent behavior of these polymer composites makes them superior nominees for microwave low absorption materials.

Effect of untreated fiber loading on the thermal, mechanical, dielectric, and microwave absorption properties of polycaprolactone reinforced with oil palm empty fruit bunch biocomposites

“…Meanwhile, the lowest dielectric constants were obtained at high frequencies (12 GHz) and high filler content (63.8%). The dielectric constant decreased with fiber loading at all frequencies . In particular, the dielectric constants in all composites decreased at increased frequency because of the polarizability of their molecules .…”

Computational and Experimental Approaches for Determining Scattering Parameters of OPEFB/PLA Composites to Calculate the Absorption and Attenuation Values at Microwave Frequencies

“…The OPEFB fiber was washed by soaking in distilled water for one day to remove the wax and other impurities. The fiber was rinsed with hot water and acetone before drying at 80 °C for 12 h in an oven [ 19 ]. Figure 3 a,b shows the procedure for the preparation of the fiber powders and OPEFB/PLA composite substructure preparation, respectively.…”

“…These effect types help indicate the material’s electrical properties involved in relative permittivity. Complex permittivity ( ) measures the effect of the material on the electric field [ 19 ]. The mathematical expression of complex permittivity is given by the following equation: where represent the real part of permittivity and is the imaginary part of permittivity.…”

Microwave Absorption Properties of Unripe Plantain Husk, Polycaprolactone and Charcoal Powder Hybrid Nanocomposites Using Numerical Simulation at X-Band Frequency

“…The flexibility and complex permittivity of polycaprolactone (PCL) makes it one of the choice polymer in fabrication EM absorber to any desired shape. Most researchers have reported the use of ferrites with fibers of oil palm and other materials [4]. Agricultural residue that are biodegradable, eco-friendly and cost effective can be used to fabricate microwave absorbers [5].…”