Physical and electrical properties of PLA-carbon composites

Kang Z. Khor,Cheow K. Yeoh,Pei L. Teh,Thangarajan Mathanesh,Wee C. Wong Techno-Press 2024 Advances in materials research Vol.13 No.3

Polylactic acid or polylactide (PLA) is a biodegradable thermoplastic that can be produced from renewable material to create various components for industrial purposes. In 3D printing technology, PLA is used due to its good mechanical, electrical, printing properties, environmentally friendly and non-toxic properties. However, the physical properties and excellent electrical insulation properties of PLA have limited its application. In this study, with the carbon black (CB) as filler added into PLA, the lattice spacing and morphology were investigated by using X-ray diffraction (XRD) and scanning electron microscope (SEM), respectively. The physical properties of PLA-carbon composite were evaluated by using tensile test, shore D hardness test and density and voids measurement. Impedance test was conducted to investigate the electrical properties of PLA-Carbon composites. The results demonstrate that the inclusion of carbon black as filler enhances the physical properties of the PLA-carbon composites, including tensile properties, hardness, and density. The addition of carbon black also leads to improved electrical conductivity of the composites. Better enhancement toward the electrical properties of PLA-carbon composites is observed with 1wt% of carbon black in N774 grade. The N550 grade with 2wt% of carbon black shows better improvement in the physical properties of PLA-carbon composites, achieving 10.686 MPa in tensile testing, 43.330 in shore D hardness test, and a density of 1.200 g/cm3 in density measurement. The findings suggest that PLA-carbon composites have the potential for enhanced performance in various industrial applications, particularly in sectors requiring improved physical and electrical properties.

Visualization of Magnetic Domains in Electrical Steel Using High-Resolution Dark-Field Imaging

김영주,김종열,Daniel Seth Hussey,Oh Youl Kwon,이승욱 대한금속·재료학회 2019 대한금속·재료학회지 Vol.57 No.6

Electrical steel is a soft magnetic steel material used in electric devices such as transformers and motors. The performance of these electric devices is primarily related to the magnetic properties of electrical steel, and the assessment of the magnetic properties of electrical steel has been considered an important topic. We use neutron grating interferometry, which is an imaging technique for visualizing the magnetic domain of electrical steel as the evaluation of magnetic properties. The dark-field image provided by neutron grating interferometry shows a sensitive contrast with respect to the magnetic domain of electrical steel due to the small angle neutron scattering generated at the domain wall. The Talbot-Lau interferometer was installed, and the feasibility test of high-resolution dark-field imaging was conducted at cold neutron imaging beamline of the NIST Center for Neutron Research. The dark-field image of electrical steel was compared with the magnetic domain image observed by the Bitter pattern based on the magnetic powder method to prove the validity of neutron grating interferometry. The dark-field image visualizes the magnetic domains of electrical steel, more detailed domain walls regardless of laser-irradiated lines than Bitter pattern result.

Bottom Ash의 전기적 특성과 일축압축강도

김태완,손영환,박재성,노수각,봉태호,Kim, Tae-Wan,Son, Young-Hwan,Park, Jae-Sung,Noh, Soo-Kack,Bong, Tae-Ho 한국농공학회 2014 한국농공학회논문집 Vol.56 No.1

The objective of this study is to find the electrical properties of Bottom ash from thermoelectric power plants in Korea. By using Parallel Plate Method, the electrical resistivity and dielectric constant were measured at the frequency from 20 Hz to 10 MHz. Also, unconfined strength test, XRF and sieve analysis were performed for finding the relationship between strength, physiochemical properties and electrical properties. In the result, the change of electrical resistivity and dielectric constant of bottom ash against frequency was similar to that of general soil. The proportion of fine grain in bottom ash had the positive correlation with dielectric constant and negative correlation with electrical resistivity. Chloride and sulfur trioxide were proportional to dielectric constant and the more bottom ash had chloride content, the lower electrical resistivity appeared in bottom ash. Unconfined strength of bottom ashes had a range from 200 kPa to 780 kPa and strength was inverse proportional to electrical resistivity.

Synthesis and Characterization of Graphene Based Unsaturated Polyester Resin Composites

Sarojini Swain 한국전기전자재료학회 2013 Transactions on Electrical and Electronic Material Vol.14 No.2

Graphene-based polymer nanocomposites are very promising candidates for new high-performance materials that offer improved mechanical, barrier, thermal and electrical properties. Herein, an approach is presented to improve the mechanical, thermal and electrical properties of unsaturated polyester resin (UPR) by using graphene nano sheets (GNS).The extent of dispersion of GNS into the polymer matrix was also observed by using the scanning electron microscopy (SEM) which indicated homogeneous dispersion of GNS through the UPR matrix and strong interfacial adhesion between the GNS and UPR matrix were achieved in the UPR composite, which enhanced the mechanical properties. The tensile strength of the nanocomposites improved at a tune of 52% at a GNS concentration of 0.05%. Again the flexural strength also increased around 92% at a GNS concentration of 0.05%. Similarly the thermal properties and the electrical properties for the nanocomposites were also improved as evidenced from the differential scanning caloriemetry (DSC) and dielectric strength measurement.

Improving the electrical properties of graphene layers by chemical doping

Khan, Muhammad Farooq,Iqbal, Muhammad Zahir,Iqbal, Muhammad Waqas,Eom, Jonghwa TaylorFrancis 2014 SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS Vol.15 No.5

<P>Although the electronic properties of graphene layers can be modulated by various doping techniques, most of doping methods cost degradation of structural uniqueness or electrical mobility. It is matter of huge concern to develop a technique to improve the electrical properties of graphene while sustaining its superior properties. Here, we report the modification of electrical properties of single- bi- and trilayer graphene by chemical reaction with potassium nitrate (KNO<SUB>3</SUB>) solution. Raman spectroscopy and electrical transport measurements showed the n-doping effect of graphene by KNO<SUB>3</SUB>. The effect was most dominant in single layer graphene, and the mobility of single layer graphene was improved by the factor of more than 3. The chemical doping by using KNO<SUB>3</SUB> provides a facile approach to improve the electrical properties of graphene layers sustaining their unique characteristics.</P>

Synthesis and Characterization of Graphene Based Unsaturated Polyester Resin Composites

Swain, Sarojini The Korean Institute of Electrical and Electronic 2013 Transactions on Electrical and Electronic Material Vol.14 No.2

Graphene-based polymer nanocomposites are very promising candidates for new high-performance materials that offer improved mechanical, barrier, thermal and electrical properties. Herein, an approach is presented to improve the mechanical, thermal and electrical properties of unsaturated polyester resin (UPR) by using graphene nano sheets (GNS). The extent of dispersion of GNS into the polymer matrix was also observed by using the scanning electron microscopy (SEM) which indicated homogeneous dispersion of GNS through the UPR matrix and strong interfacial adhesion between the GNS and UPR matrix were achieved in the UPR composite, which enhanced the mechanical properties. The tensile strength of the nanocomposites improved at a tune of 52% at a GNS concentration of 0.05%. Again the flexural strength also increased around 92% at a GNS concentration of 0.05%. Similarly the thermal properties and the electrical properties for the nanocomposites were also improved as evidenced from the differential scanning caloriemetry (DSC) and dielectric strength measurement.

A basic research on correlation analysis of electrical-chemical-mechanical characteristics for estimating mechanical properties

Yong-Seok Lee(이용석) 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.11

The materials properties are very important not only for research but also for industries that use various materials. Many industries and researchers have tried to measure materials properties. However, most of the research on materials properties have been conducted by focusing on only one characteristic. In hence, it is difficult to discover the correlation between each characteristic of the material. The electrical-chemical-mechanical properties of materials appear characteristics based on the atomic structure of materials. If the atomic structure is changed, the electrical, chemical, and mechanical properties will be effected and are expected to correlation among them. Therefore, we propose basic experiments that can analyze the correlation among electrical-chemical-mechanical properties for predicting mechanical properties of new materials in this research.

Improved Mechanical and Electrical Properties of Carbon Nanotube Yarns by Wet Impregnation and Multi-ply Twisting

이유리,박준범,정영진,박종승 한국섬유공학회 2018 Fibers and polymers Vol.19 No.12

Carbon nanotube (CNT) fibers, composed entirely of CNT bundles, have inferior mechanical properties as adjacent CNTs slide past each other when an external force is applied. Numerous surface coatings have been tried, but all these approaches have caused severe damage to the electrical properties of the resulting fibers. As a measure to address these problems, we present an effective method for the enhanced mechanical and electrical properties of CNT yarns by wet impregnation with a poly(vinylidene fluoride)/ionic liquid (PVDF/IL) composite and subsequent multiply twisting. Single twisting of three-ply yarns showed a superior electrical conductivity of up to 1500 S/cm, while braided twisting of pretwisted yarns exhibited excellent tensile performances, with a load capacity of 3.2 N, tensile strength of 12.7 g/de, and tensile strain of 35.2 %. The polarized Raman measurements confirmed the elevated CNT quality and high alignment of CNT bundles. The proposed approach of impregnated and twisted CNT yarns will lead to a variety of potential applications in sensors/actuators, e-textile devices, and fiber-shaped electrodes, which simultaneously requires ultra-light weight and good electrical and tensile properties.

Effect of filler type on electrical and mechanical properties of conductive fillers/thermoplastic polymer composites

진영철,최웅기,정용식,서민강 한국공업화학회 2015 한국공업화학회 연구논문 초록집 Vol.2015 No.1

Most of thermoplastic polymers can become conductive materials when added with some kinds of conducting particles, such as carbon blacks (CBs), carbon fibers (CFs), then the composites have the electrical and mechanical properties. In this work, the effect of filler type on electrical and mechanical properties of conductive filler/thermoplastic polymer composites were investigated. The thermoplastic polymers were high density polyethylene (HDPE) and the conductive fillers were carbon blacks and milled-carbon fibers. Conductive fillers content was added up to 30 wt.% in composites. Electrical and mechanical properties of the composites were studied by resistivity on temperature, tensile strength, and impact strength measurements. Morphologies of the composites were measured by SEM.

Electrical Properties of a High Tc Superconductor for Renewed Electric Power Energy

Lee Sang-Heon The Korean Institute of Electrical Engineers 2006 Journal of Electrical Engineering & Technology Vol.1 No.3

Effects of $Ag_2O$ doping on the electromagnetic properties in the BiSrCaCuO superconductor. The electromagnetic properties of doped and undoped $Ag_2O$ in the BiSrCaCuO superconductor were evaluated to investigate the contribution of the pinning centers. It was confirmed experimentally that a larger amount of magnetic flux was trapped in the $Ag_2O$ doped sample than in the undoped one, indicating that the pinning centers of magnetic flux are related closely to the occurrence of the magnetic effect. We have fabricated superconductor ceramics by the chemical process. A high Tc superconductor with a nominal composition of $Bi_2Sr_2Ca_2Cu_3O_y$ was prepared by the organic metal salts method. Experimental results suggest that the intermediate phase formed before the formation of the superconductor phase may be the most important factor. The relation between electromagnetic properties of Bi HTS and the external applied magnetic field was studied. The electrical resistance of the superconductor was increased by the application of the external magnetic field. But the increase in the electrical resistance continues even after the removal of the magnetic field. The reason is as follows; the magnetic flux due to the external magnetic field penetrates through the superconductor and the penetrated magnetic flux is trapped after the removal of the magnetic flux. During the sintering, doped $Ag_2O$ was converted to Ag particles that were finely dispersed in superconductor samples. It is considered that the area where normal conduction takes place increases by adding $Ag_2O$ and the magnetic flux penetrating through the sample increases. The results suggested that $Ag_2O$ acts to amplify pinning centers of magnetic flux, contributing to the occurrence of the electromagnetic properties.