Ultrasonic Characterisation of Epoxy Resin/Polyethylene Terephthalate (PET) Char Powder Composites

This study is carried out in order to determine the elastic properties of the Epoxy Resin (ER) / Polyethylene terephthalate (PET) Char Powder Composites by ultrasonic wave velocity measurement method. Plastic waste was recycled as raw material for the preparation of epoxy composite materials. The supplied chars were mixed with epoxy resin matrix at weight percentages of 10 %, 20 % and 30 % for preparing ER/PET Char Powder (PCP) composites. The effect of PET char powder on the elastic properties of ER/PCP composites were investigated by ultrasonic pulse-echo method. According to the obtained results, the composition ratio of 80:20 is the most appropriate composition ratio, which gave the highest elastic constants values for ER/PCP composites. On the other hand, the best electrical conductivity value was obtained for 70:30 composition ratio. It was observed that ultrasonic shear wave velocity correlated more perfectly than any other parameters with hardness.DOI: http://dx.doi.org/10.5755/j01.ms.22.4.12190</p

PECVD application to obtain polymer coated graphene nanoplatelets and development of new epoxy nanocomposites

In this study, graphene nanoplatelets (GNPs) were synthesized from graphite by a liquid-phase exfoliation (layer separation) method, and their surfaces were functionalized with poly(glycidyl methacrylate) (PGMA) by using the rotatingbed plasma-enhanced chemical vapor deposition (PECVD) method. Fourier-transform infrared spectroscopy (FT-IR), Raman spectroscopy, scanning electron microscopy (SEM), X-ray powder diffraction (XRD), and thermogravimetric (TGA) analyses were performed to characterize the unmodified (u-GNP) and modified GNP (PGMA-GNP). Epoxy nanocomposites were prepared with both types of GNPs at different loading levels (0.1–2% by weight). The role of the surface modification of the GNPs on the mechanical, thermal, electrical conductivity, contact angle, water sorption, and corrosion properties of the epoxy nanocomposite coatings was also investigated. Consequently, the tensile strength and Young’s modulus of the epoxy resin (ER)/PGMA-GNP nanocomposites were enhanced by 10.2–20 and 3.3–18.4%, respectively, as compared to the ER/u-GNP composites. Moreover, the nanocomposites prepared with PGMA-GNP had better water sorption and wettability properties than those prepared with u-GNP, but lower electrical conductivity. The corrosion test results showed that the addition of GNPs to epoxy effectively improved the corrosion resistance of the epoxy composites in high salinity, basic, and acidic environments

Determining the Elastic Properties of Modified Polystyrenes by Sound Velocity Measurements

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 computer-controlled 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. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 121: 3425-3432, 201