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.

Determination of mechanical and damping properties of hazelnut shell powder reinforced biocomposites by ultrasonic method

“…A remarkable increase was obtained in densities about 4.26%, 4.73%, and 4.74% for BC‐5, BC‐10 , and BC‐15 biocomposites, respectively, compared to the neat BER matrix. These results agree well with the density results of related literature 2,17 …”

“…A novel synthesized bio‐based epoxy resin (BER) 2 was used as the matrix material. Also, the 2,4,6‐tris (dimethyl aminomethyl) phenol, and the aromatic m‐xylene diamine (MXDA) were used as accelerator and hardener, respectively.…”

“…BER was synthesized by the esterification reaction using bio‐based sebacic acid and epichlorohydrin. The detailed information about synthesis and characterization was given in the previous study of authors 2 …”

“…Especially, bio‐filler reinforced polymer matrix is an interesting area of research. Consequently, many types of research have been conducted to fabricate biocomposites 1–3 . The bio‐fillers used in eco‐friendly biocomposites are plentiful, inexpensive, light, and have high specific modulus 4 .…”

“…Instead of these DTs, ultrasonic testing (UT) method, which is both more economical and more sensitive, has been developed. UT method has been proven in isotropic material characterization 2,22,23 . Recently, different biocomposites have been investigated using UT methods 2,17,24 .…”