Effect of Processing on the Microstructure and Electrical Conductivity of Hot Pressed PMMA/ITO Bulk Nanocomposites

2006 ◽  
Vol 977 ◽  
Author(s):  
Charles J. Capozzi ◽  
Rosario A. Gerhardt
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
Polymer Matrix ◽  
Indium Tin Oxide ◽  
Polymer Matrix Composites ◽  
Processing Parameters ◽  
Specimen Thickness ◽  
Matrix Composites ◽  
Matrix Nanocomposites ◽  
Network Microstructure

AbstractThere are few studies that discuss the effect of the fabrication conditions and bulk thickness on the electrical conductivity of hot pressed polymer-matrix composites. For polymer-matrix composites that possess a segregated-network microstructure, the processing parameters can significantly impact the electrical properties and microstructure of the composite material. Our group has recently fabricated novel polymer-matrix nanocomposites, which possess a segregated network microstructure containing regular, polyhedral-shaped polymer matrix particles1-2. This paper investigates the effect of processing pressure and specimen thickness on the electrical properties and microstructure of hot pressed poly(methyl methacrylate) (PMMA) containing segregated networks of indium tin oxide (ITO) nanopowders.

UV Photopatternability and Electrical Properties of GnF/SU-8 Composites Controlled by GnF Concentration

2018 ◽  
Vol 765 ◽  
pp. 60-64
Author(s):  
Seung Pyo Woo ◽  
Sung Min Park ◽  
Gyung Mok Nam ◽  
Young Choi ◽  
Sang Heon Park ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
Polymer Matrix ◽  
Material Properties ◽  
Polymer Matrix Composites ◽  
Matrix Composites ◽  
Electrically Conductive ◽  
Screening Effect ◽  
Unique Material ◽  
Uv Dose

The GnF/SU-8 composites are new polymer matrix composites (PMCs) composed of graphite nanoflakes (GnFs) bound together by SU-8 photoresist. The PMCs therefore have excellent ultraviolet (UV) photopatternability and high electrical properties. In spite of the unique material properties of GnF/SU-8 composites, much still remains uncertain about their controllability in both UV photopatternability and electrical properties. Here, we investigate 7 kinds of GnF/SU-8 composites having different GnF concentrations of 5.0 to 25.0 wt.% to characterize the changes in the UV photopatternability (i.e., polymerized thickness and photopattern quality) and electrical conductivity of GnF/SU-8 composites caused by a variation in GnF concentration. The polymerized thickness of GnF/SU-8 composites is measured to be in the range of 4.06 to 23.99 μm, which is inversely proportional to GnF concentration and also directly proportional to UV dose (i.e., 345 to 3,450 mJ/cm2) because of the screening effect of GnF existed in the composites; the photopattern quality at the edge is in inverse proportion to GnF concentration. An increase in GnF concentration leads to a significant change in the electrical conductivity of GnF/SU-8 composites in a proportional way (up to 25.34 S/m). The GnF/SU-8 composites are expected to be widely used as UV photopatternable and electrically conductive PMCs for diverse engineering applications.

Effects of the Mould Pressure and Mould Pressing Time on the Properties of Graphite/Phenolic Resin Composites

2013 ◽  
Vol 706-708 ◽  
pp. 95-98
Author(s):  
Mi Dan Li ◽  
Dong Mei Liu ◽  
Lu Lu Feng ◽  
Huan Niu ◽  
Yao Lu
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Flexural Strength ◽  
Polymer Matrix ◽  
Phenolic Resin ◽  
Polymer Matrix Composites ◽  
Resin Composites ◽  
Matrix Composites ◽  
Natural Graphite ◽  
Pressing Time

Polymer matrix composites made from phenolic resin are filled with natural graphite powders. They are fabricated by compression molding technique. The density, electrical conductivity and flexural strength of composite are analyzed to determine the influences of mould pressure and mould pressing time on the physical, electrical and mechanical properties of composite. It is found that the density, electrical conductivity and flexural strength of composites increased with increasing mould pressure. Under pressure of 40 MPa for 60 min, the density, electrical conductivity and flexural strength of composites were 1.85 g/cm3, 4.35  103 S/cm and 70 MPa, respectively. The decreased gaps could be the main reason for the increasing of density, electrical conductivity and flexural strength as mould pressure increases. The results also show that the density of composites increased with increasing mould pressing time.

Percolation and Electrical Conductivity Modeling of Novel Microstructured Insulator-Conductor Nanocomposites Fabricated from PMMA and ATO

2014 ◽  
Vol 1692 ◽  
Author(s):  
Youngho Jin ◽  
Rosario A. Gerhardt
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
Percolation Threshold ◽  
Polymer Matrix ◽  
Polymer Matrix Composites ◽  
Conductive Filler ◽  
Molding Pressure ◽  
Shape Transformation ◽  
Element Analysis ◽  
3D Network

ABSTRACTThe electrical conductivity of insulating polymer matrix composites undergoes radical increase at a certain concentration of conductive filler, which is known as the percolation threshold. Polymer matrix conductive nanocomposites were fabricated by compression molding the mechanically mixed poly (methyl methacrylate) (PMMA) and antimony tin oxide (ATO) nanoparticles, as has been done with other polymer composites before. The electrical conductivity of PMMA/ATO nanocomposites increased by several orders of magnitude at a small concentration of ATO (∼ 0.27 vol %). The continuous 3D network like distribution of ATO nanoparticles contributed to this percolation at subcritical filler concentrations. The effects of processing parameters on these unique microstructures and electrical properties were investigated. The tetrakaidecahedron-like microstructure was observed by scanning electron microscopy (SEM) and was found to be affected by the molding pressure, temperature and amount of nanoparticles. The viscoelastic flow of matrix under the optimum processing conditions allowed the shape transformation of PMMA into space filling polyhedra and an ordered distribution of ATO nanoparticles along the sharp edges of the PMMA. Parametric finite element analysis was performed to model this unique microstructure-driven percolation. The 2D simplified model was generated in AC/DC frequency domain mode in COMSOL Multiphysics® to solve the effects of ordered distribution of conductive nanoparticles on the electrical properties of the composite. There was excellent agreement between experimental and simulated values of electrical conductivity and percolation concentration. This model can be used to predict percolation threshold and electrical properties for any types of composite systems containing insulating matrix and conductive fillers that can form this unique microstructure.

Phase transformation effects on the wear properties of alumina gel–polymer matrix nanocomposites

2001 ◽  
Vol 16 (6) ◽  
pp. 1680-1685 ◽  
Author(s):  
Jiazhong Luo ◽  
John Lannutti ◽  
Robert Seghi
Keyword(s):  
Phase Transformation ◽  
Polymer Matrix ◽  
Polymer Matrix Composites ◽  
Growth Patterns ◽  
Matrix Composites ◽  
Wear Properties ◽  
Wear Rates ◽  
Alumina Gel ◽  
Matrix Nanocomposites ◽  
Polymer Matrix Nanocomposites

A phase transformation in an alumina gel provided an elegant means of isolating the effect of filler properties on the wear resistance of particle-reinforced thermosetting polymer–matrix composites. This transformation was useful because it takes place without significantly altering filler porosity. This produced a wear surface apparently reflecting the vermicular growth patterns in the γ-alumina in the δ-aluminum monohydrate matrix. Nucleation of γ-alumina in the gel matrix produced wear rates comparable to commercial composites.

scholarly journals Review of Polymer Composites with Diverse Nanofillers for Electromagnetic Interference Shielding

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 541 ◽  
Author(s):  
Dimuthu Wanasinghe ◽  
Farhad Aslani ◽  
Guowei Ma ◽  
Daryoush Habibi
Keyword(s):  
Electrical Conductivity ◽  
Polymer Composites ◽  
Polymer Matrix ◽  
Electromagnetic Interference ◽  
Polymer Matrix Composites ◽  
Morphological Properties ◽  
Matrix Composites ◽  
Emi Shielding ◽  
Alternative Materials ◽  
Metallic Panels

Polymer matrix composites have generated a great deal of attention in recent decades in various fields due to numerous advantages polymer offer. The advancement of technology has led to stringent requirements in shielding materials as more and more electronic devices are known to cause electromagnetic interference (EMI) in other devices. The drive to fabricate alternative materials is generated by the shortcomings of the existing metallic panels. While polymers are more economical, easy to fabricate, and corrosion resistant, they are known to be inherent electrical insulators. Since high electrical conductivity is a sought after property of EMI shielding materials, polymers with fillers to increase their electrical conductivity are commonly investigated for EMI shielding. Recently, composites with nanofillers also have attracted attention due to the superior properties they provide compared to their micro counterparts. In this review polymer composites with various types of fillers have been analysed to assess the EMI shielding properties generated by each. Apart from the properties, the manufacturing processes and morphological properties of composites have been analysed in this review to find the best polymer matrix composites for EMI shielding.

Polymer Matrix Composites with Particles of TiC Obtained by a Sol-Gel Method

2005 ◽  
Vol 106 ◽  
pp. 141-144 ◽  
Author(s):  
K. Konopka ◽  
Anna Biedunkiewicz ◽  
Anna Boczkowska ◽  
Zbigniew. Rosłaniec ◽  
Krzysztof Jan Kurzydlowski
Keyword(s):  
Polymer Matrix ◽  
Polymer Matrix Composites ◽  
Sol Gel ◽  
Matrix Composites ◽  
Gel Method ◽  
Sol Gel Method ◽  
Force Microscopy ◽  
Tic Nanoparticles ◽  
Matrix Nanocomposites ◽  
Polymer Matrix Nanocomposites

Nanoparticles of carbides, nitrides and carbonitrides can be used to reinforce polymer matrix nanocomposites to obtain the required strength, hardness, corrosion and wear resistance. In order to efficiently achieve the desirable properties the polymer matrix and nanoparticles must be optimised. This paper reports on studies undertaken on TiC reinforced polymer matrix nanocomposites. The TiC nanoparticles were produced by sol-gel method and nanocomposites were obtained in situ, via the reaction and synthesizing of polyether-ester copolymer (PEE). TiC nanoparticles were characterised with a scanning electron microscopy (SEM) and the microstructure of the composites was examined by SEM and atomic force microscopy (AFM). Tensile properties were determined. For comparison, samples of polymer were also studied and composites with submicron size of TiC particles. The results, which are discussed in terms of size of the TiC particles, showed that the particles incorporated in the polymer matrix, influence the strength of the composites.

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