In this study, the composites of diglycidyl ether of bisphenol A (DGEBA) epoxy resin that have been formed by mixing epoxy resin with allyl glycidyl ether (AGE) and 2,3-epoxypropyl methacrylate [glycidyl methacrylate (GMA)] were prepared in weight % ratios of 90 : 10, 80 : 20, and 70 : 30. A computer controlled analyzer with 35 MHz and a digital oscilloscope with 60 MHz were used for measuring the velocities of ultrasonic wave. The measurement of ultrasonic velocity carried out by pulse echo method at frequencies of 2.25 and 3.5 MHz at room temperature. The values of acoustic impedance (Z), Poisson ratio (l), and coefficients of elasticity (L, G, K, E) of composites were calculated by values of densities and velocities that obtained. Thus, the effect of modificating epoxy resin (DGEBA) by AGE and GMA on mechanical properties of DGEBA was investigated using the ultrasonic method. Atomic force microscopy has been used for determining the microstructure of composites. By the results obtained from the investigation, it have been established that the longitudinal and shear ultrasonic wave velocities, and the values of all the elasticity constants of DGEBA were increased by modification with AGE and GMA. Also the most suitable combination ratio for the compound of DGEBA : AGE and DGEBA : GMA has been found as 80 : 20.

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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.

The effect of the binding of various polyfunctional groups to polystyrene's (PS's) aromatic ring on the elastic properties of the PS were investigated by an ultrasonic method. Various sets of samples were prepared by chemical modification of pure PSs having different molecular weights with SA, maleic anhydride, and phthalic anhydride. The ultrasonic wave velocities of modified PSs were measured with the pulse-echo method at room temperature by a computercontrolled analyzer and a digital oscilloscope. The values of the acoustic impedance, Poisson's ratio, and elasticity constants of the samples were calculated by the measured values of the densities and sound velocities. The longitudinal and shear wave velocities and the values of all elastic constants increased with chemical modification of the pure PS.

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Non‐destructive techniques are suitable alternatives for characterization of composites. The aim of this study is to analyze the composites of epoxy resin (ER)/marble waste powder (MWP) by ultrasonic method. The effects of marble powder, coagulant type, and dosage on the ultrasonic properties of ER/MWP composites were investigated. The ultrasonic wave velocities of composites were measured with the pulse–echo method at room temperature by a flaw detector. The values of the acoustic impedance, Poisson's ratio, and elastic constants of the samples were calculated by the measured values of the densities and both longitudinal and shear ultrasonic wave velocities. According to the results, the ER/MWP composite using sepiolite coagulant in dosages of 4 g/500 mL has showed the highest values of elastic constants. POLYM. COMPOS. 36:584–590, 2015. © 2014 Society of Plastics Engineers

This study is carried out in order to determine the elastic properties of Epoxy Resin (ER) Composites reinforced with various mixtures of China Poplar Char (CPC) and Pine Cone Char (PCC) as biochars by ultrasonic wave velocity measurement method. The prepared chars are mixed with epoxy resin matrix at weight percentages of 10%, 20%, and 30% for preparing the ER/Biochars (BC) composites. The effect of biochar amounts on the elastic properties of the ER/ BC composites are investigated by ultrasonic pulse echo overlap method. The morphologies of the samples are investigated by scanning electron microscopy. Based on the findings obtained from the present study, forming of the ER/CPC composites gives better values of elastic properties compared to forming of the ER/ PCC composites. According to the obtained results, the composition ratio of 70:30 is the most appropriate composition ratio for both of the ER/CPC and the ER/ PCC composites.

In this study, first the pure polystyrenes (PS) with different molecular weights (350 Â 10 3 and 500 Â 10 3 ) have been modified by the chemical modification with succinic anhydride (SA), maleic anhydride (MA), and phthalic anhydride (PhA) and then the polystyrene based composites (CPS) prepared by addition of modified polystyrenes (MPS) into pure PS (with the molecular weight of 230 Â 10 3 ) in weight % ratios of 90 : 10, 80 : 20, and 70 : 30. Ultrasonic measurements were performed on PS/MPS blends of different weight percent of MPSs by use of pulse echo method with 5-MHz frequency at room temperature. Elastic properties namely; longitudinal modulus (L), Young's modulus (E), bulk modulus (K) and shear modulus (G), Poisson's ratio (l), and acoustic impedance (Z) were calculated from the ultrasonic velocities values measured and densities values obtained experimentally. Atomic force microscopy (AFM) has been used for determining the microstructure of composites. The variations of these parameters with increasing MPSs weight percentage content in PS/MPS from 10 to 30 have been discussed.