Claudio Scarponi
Abstract
The purpose of the paper is the description of the main applications of the so-called “Green Composites”, composed by natural fibers, such as hemp and flax, embedded by bio-polymers and the contribution of such materials to the reduction of the environmental pollution. Since the Kyoto Conference ...
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The purpose of the paper is the description of the main applications of the so-called “Green Composites”, composed by natural fibers, such as hemp and flax, embedded by bio-polymers and the contribution of such materials to the reduction of the environmental pollution. Since the Kyoto Conference at the end of 90’s of the last century, there is higher and higher attention to the concepts of sustainability. The market of composite materials based on synthetic resins and synthetic fibers, such as glass and carbon fibers, is huge. Billions of tons worldwide are used in the fields of civil constructions, marine constructions, sport goods, automotive, aerospace constructions. After a short description of the most interesting bio-polymers and natural fibers of interest worldwide, the paper describes the products developed nowadays and future possibilities for more applications, with care to future applications in aeronautical constructions.
Richa Sharma; N. C. Mehra; R. P. Tandon
Abstract
In the present work, the composite series (1-x) Ba0.94Ca0.06TiO3 - (x) Ni0.7Co0.1Zn0.2Fe2O4 (where x = 0.1, 0.2, 0.3 and 0.4 wt. fraction) was synthesized by solid state reaction method followed by conventional sintering. The structure and morphology of prepared samples were examined using X-ray diffractometer ...
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In the present work, the composite series (1-x) Ba0.94Ca0.06TiO3 - (x) Ni0.7Co0.1Zn0.2Fe2O4 (where x = 0.1, 0.2, 0.3 and 0.4 wt. fraction) was synthesized by solid state reaction method followed by conventional sintering. The structure and morphology of prepared samples were examined using X-ray diffractometer (XRD) and scanning electron microscopy (SEM), respectively. In addition, dielectric constant (ε΄) and loss tangent (tan δ) of prepared samples were measured as a function of frequency and temperature. The room temperature values of dielectric constant (ε΄) of composite samples are found to decrease from 529.29 to 159.52 as ferrite content increased from x = 0.1 to x = 0.4 at 1 kHz frequency. Moreover, in the dielectric constant vs. temperature plots of the composite samples, ferroelectric to paraelectric phase transition of pure Ba0.94Ca0.06TiO3 is observed. Furthermore, ferroelectric and magnetic properties of the composite samples were studied at room temperature. With increasing addition of the ferrite content in the composites, the ferroelectric properties get weakened and the magnetic behavior of the composite samples improved. The maximum values of saturation magnetization ( ) and remanant magnetization ( ) are 22.52 emu/gm and 3.39 emu/gm, respectively, for composite sample containing 0.4 wt. fraction Ni0.7Co0.1Zn0.2Fe2O4. Copyright © 2017 VBRI Press.
