Preparation and Ultrasonic Characterization of Modified Epoxy Resin/Coconut Shell Powder Biocomposites

Abstract

A new bio-based epoxy resin (BER) is produced by the esterification reaction between sebacic acid (SAc) as bio-based acid and epichlorohydrin (ECH). The epoxy resin (ER) is modified with the BER. The biocomposites are prepared using untreated coconut shell powder (CSP), modified coconut shell powder (MCSP), and MER. The CSP and MCSP particles are mixed with MER in varied compositions (10-50 wt%) for preparation of the MER/CSP and MER/MCSP biocomposites. The influences of CSP and MCSP bio-fillers amounts on the physical properties (density, elastic constants, acoustic impedance, ultrasonic micro-hardness, and attenuation coefficient) of biocomposites are investigated using the ultrasonic pulse-echo overlap method (PEOM). It was seen that the densities, both ultrasonic longitudinal and shear waves' velocity values of obtained biocomposites were higher than those of the MER. All elastic moduli of the MER/MCSP biocomposites have higher values than of the neat MER and MER/CSP biocomposites.