Graphite/UPE Nanocomposite: Transport, Thermal, Mechanical and Viscoelastic Properties

2019 ◽  
Vol 23 ◽  
pp. 201-212
Author(s):  
Shivkumari Panda ◽  
Dibakar Behera ◽  
Tapan Kumar Bastia

This chapter presents the preparation and characterization of some unique properties of nanocomposites by dispersing graphite flakes in commercial unsaturated polyester (UPE) matrix. The composite was prepared by a novel method with the use of solvent swelling technique. Three different specimens of UPE/graphite nanocomposites were fabricated with addition of 1, 2 and 3 wt% of graphite flakes. Except mechanical, viscoelastic and thermo gravimetric properties, transport properties like electrical conductivity, thermal conductivity and water transport properties were studied for the first time. Graphite flakes propose enhanced properties to the composites suggesting homogeneous distribution of the nanofiller in the matrix and strong interaction with the matrix. 2wt% nanofiller loading showed superior essential characteristics and after that the properties reduced may be due to the nucleating tendency of the nanofiller particles. The XRD pattern showed the compatibility of the graphite flakes by introducing a peak around 26.550 in the nanocomposites. SEM Properties are also in agreement with the compatibility. Nanocomposite with 2wt% graphite also showed remarkable enhancement in transport, mechanical, viscoelastic and thermo gravimetric properties. So by introduction of a small quantity of graphite endow the new class of multiphase nanocomposites with inimitable structure and tremendous application.

2019 ◽  
Vol 31 (9) ◽  
pp. 1943-1948
Author(s):  
Priyabrata Mohanty ◽  
Tapan Kumar Bastia ◽  
Dibakar Behera ◽  
Shivkumari Panda

This work represents the preparation and characterization of some unique properties of vinyl ester (VE) and unsaturated polyester (UPE) blend based nanocomposites by introducing biopolymer chitosan grafted multi-walled carbon nanotubes (MWCNTs). Initially, surface grafting of MWCNTs with chitosan was performed by utilizing glutaraldehyde as a cross linking reagent through covalent deposition method and are successfully characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy(SEM). Then 50:50 wt % of vinyl ester and unsaturated polyester blend was prepared by simple sonication method. Three different specimens of VE/UPE/CS-g-MWCNTs nanocomposites were fabricated with addition of 1, 3 and 5 wt % of functionalized bionanofiller. Chitosan grafting of MWCNTs offered enhanced properties to the nanocomposites suggesting homogeneous distribution of the nanofiller in the matrix with minimum corrosion and swelling properties. 3 wt % of functionalized bionanofiller loading showed superior essential characteristics and after that the properties reduced may be due to the nucleating tendency of the nanofiller particles.


2019 ◽  
Vol 25 ◽  
pp. 22-31 ◽  
Author(s):  
Farhana Islam ◽  
M. Naimul Islam ◽  
Shahirin Shahida ◽  
Harun Ar Rashid ◽  
Nanda Karmaker ◽  
...  

Jute fabrics reinforced Unsaturated Polyester Resin (UPR)-based composites were prepared by conventional hand lay-up technique. Different proportions (5 to 50% by weight) of fibre content was used in preparation of the composite. Tensile Strength (TS), Tensile Modulus (TM), Bending Modulus (BM), Bending Strength (BS), Impact Strength (IS) of the fabricated composites were studied. Upon each addition of fiber content in the matrix, mechanical properties of the composites were increased. The Tensile Strength (TS) of the 5% and 50% fiber reinforced composites was 18 MPa and 42 MPa respectively. Scanning Electron Microscopy (SEM) showed interfacial properties of the composites and it was revealed that the bond between fiber and matrix was excellent.


2020 ◽  
Vol 57 (3) ◽  
pp. 52-60
Author(s):  
Mohamed Farsane ◽  
Abdellah Anouar ◽  
Souad Chah ◽  
Miloud Bouzziri

In this study, the composites of ceramic waste filler polyester were produced with ceramic waste as the filler and unsaturated polyester resin as the matrix. Various weight of filler loads (particle size [180 �m) were used; 0, 28.5, 41 and 50 wt% in view to better understand the effect of filler content on the mechanical, thermal properties and water absorption of the composites. Additionally, Fourier transform infrared spectroscopy was used to characterize the samples, from the findings, it is noticed an increase in the level of porcelain powder decreased the flexural strength and Hardness and increased the density. The results of water absorption have shown the composites absorbs fewer water. Thermal degradation indicates that the composite is more resistant to temperature than unsaturated polyester matrix due to the effect of porcelain powder incorporated. Moreover, the results reveal an opportunity for using the ceramic waste as filler in unsaturated polyester resin formulation.


Author(s):  
Nirmal Halder

<p><span>Characterization of tea waste, cooked waste has been done by various authors but for the first time it has been done for understanding the necessity of thermophilic digestion. And for this kind of digestion takes place in thermophilic digester for efficient biogas production. Detailed morphological analysis of feedstock has been determined. In the present study, thermo gravimetric analysis carried out For easy and fast digestion of cooked waste, a novel design of thermophilic digester is proposed and tested.</span></p>


Author(s):  
Jean-Paul K. Gomis ◽  
Patrice Berthod ◽  
Erwann Etienne

The six alloys the thermal properties of which and the tendency to oxide spallation of which were studied in the first two parts of this work, were here characterized after oxidation for 70 hours at 1250°C. The external chromia scale, and also the CrTaO4 subsurface oxide, formed for all the alloys, almost independently of the Co and Ni proportions in the base element content. But, because of the formation of more CrTaO4 for the nickel-richest alloys probably due to the higher availability of Ta in the matrix and its easier diffusion towards the neighbourhood of the oxidation front, the adherence of chromia was weakened and spallation, suggested by the thermogravimetric curves in the second part of this work, is here really observed and the denuded part of alloys clearly seen. The degradation of the subsurface, which can be in a first time summarized by the development of a carbide-free zone and a {Cr, Ta}-depleted zone, depends on the Co and Ni proportions. The microstructure of the bulk is differently affected by long exposure at elevated temperature. The changes in carbide population characteristics are stronger for the nickel-based alloys than for the cobalt-based ones. Finally, the isothermal oxidation behaviour is best for the nickel-richest alloys but the oxide spallation behaviour and the potential mechanical properties are the best for the cobalt-richest alloys.


MRS Advances ◽  
2019 ◽  
Vol 4 (46-47) ◽  
pp. 2471-2477
Author(s):  
Chaoxing Zhang ◽  
Teresa H. Wen ◽  
Khaleel A. Razak ◽  
Jiajia Lin ◽  
Edgar Villafana ◽  
...  

ABSTRACT:Neural electrodes have been widely used to monitor neural signals and/or deliver electrical stimulation in the brain. Currently, biodegradable and biocompatible materials have been actively investigated to create temporary electrodes that could degrade after serving their functions for neural recording and stimulation from days to months. The new class of biodegradable electrodes eliminate the necessity of secondary surgery for electrode removal. In this study, we created biodegradable, biocompatible, and implantable magnesium (Mg)-based microelectrodes for in vivo neural recording for the first time. Specifically, conductive poly-3,4-ethylenedioxythiophene (PEDOT) was first deposited onto Mg microwire substrates by electrochemical deposition, and a biodegradable insulating polymer was subsequently sprayed onto the surface of electrodes. The tip of electrodes was designed to be conductive for neural recording and stimulation, while the rest of electrodes was insulated with a polymer that is biocompatible with neural tissue. The impedance of Mg-based microelectrodes and their performance during neural recording in the auditory cortex of a mouse were studied. The results first demonstrated the capability of Mg-based microelectrodes for in vivo recording of multi-unit stimulus-evoked activity in the brain.


e-Polymers ◽  
2002 ◽  
Vol 2 (1) ◽  
Author(s):  
Stefano Fiori ◽  
Giulio Malucelli ◽  
Alberto Mariani ◽  
Laura Ricco ◽  
Elena Casazza

AbstractThe frontal polymerization technique has been successfully applied, for the first time, to obtain an unsaturated polyester/styrene resin. The effect of the ratio of the two aforementioned components, as well as of the type and amount of free-radical initiator on both front velocity and maximum temperature reached by the front, has been thoroughly studied. The resulting products have been characterized in terms of their thermal and dynamic-mechanical behaviour. A comparison of such products with the corresponding materials obtained by the classical batch polymerization technique has evidenced that frontal polymerization allows to reach a higher degree of crosslinking with respect to batch copolymerization and hence a better thermal and mechanical behaviour.


2014 ◽  
Vol 10 (S305) ◽  
pp. 313-318
Author(s):  
A. Cellino ◽  
S. Bagnulo

AbstractAsteroid polarimetry has taken profit in recent years of a renewed interest triggered by exciting results from observing campaigns and theoretical studies. One of the most important applications of polarimetry to asteroid studies is the derivation of the geometric albedo and of the typical sizes of the particles forming the regolith layer covering the surface. Moreover, the serendipitous discovery of a new class of asteroids displaying unusual polarimetric properties, the so-called “Barbarians”, has been followed by increasing evidence that these objects can be extremely primitive and may be interpreted as remnants of the very first generation of solid bodies accreted in the inner Solar System. In addition, some results of asteroid polarimetry are going to be interpreted, for the first time, in terms of some “ground truth” evidence, made possible by in situ observations of the surface of the asteroid (4) Vesta by the Dawn space probe. Finally, some preliminary evidence suggests that spectro-polarimetry is going to become a major tool for the physical characterization of the small bodies of the solar system.


2014 ◽  
Vol 60 (2) ◽  
pp. 411-420
Author(s):  
Asha Goel ◽  
Satbir Singh

Abstract The nature and usefulness of KC functions in topology have been well established in literature. In this paper, we introduce a new class of functions to be called inversely KC functions and emphasize its utility in characterization of functions with closed graph for the first time. We hereby study the relation between KC functions and Inversely KC functions and investigate various specific conditions under which these functions can be converted into functions having closed graph.


RSC Advances ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 3529-3538 ◽  
Author(s):  
Yue Zhang ◽  
Ting-Ting Li ◽  
Hai-Tao Ren ◽  
Fei Sun ◽  
Qi Lin ◽  
...  

In this paper, a novel bi-layered Janus fibrous electrospun membrane with robust moisture permeable, breathable and directional water transport properties is successfully fabricated and reported for the first time.


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