Teh Pei Leng
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Preferred name
Teh Pei Leng
Official Name
Teh. Pei Leng
Alternative Name
Leng, T. Pei
Leng, T. P.
Teh, P. L.
Leng, Teh Pei
Main Affiliation
Scopus Author ID
6701800182

Research Output
Now showing 1 - 10 of 14
  • Publication
    Mechanical and electrical performances of different silicone rubber content in polyurethane elastomer/silicone rubber/graphene nano-platelets conductive material
    ( 2021-07-21)
    Heng C.W.
    ;
    Teh Pei Leng
    ;
    Nor Azura Abdul Rahim
    ;
    Yeoh Cheow Keat
    Immiscible polyurethane elastomer (PUE)/silicone rubber/graphene nano-platelets blend composites filled with different PUE/silicone rubber blend ratio were synthesised by using solution casting technique. In this work, two different types of silicone rubber: liquid silicone rubber (LSR) and powdered silicone rubber (PSR) were used as secondary matrix based on double percolation concept to construct an immiscible blend that has a balance electrical conductivity and mechanical properties. The electrical conductivity has increased gradually, but the mechanical properties of the composites shows a remarkable decline when silicone rubber loading increases up to 20 vol% for both blend systems. The well balance of electrical conductivity and performance is achieved at 15 vol.% of silicone rubber loading. Overall, PUE/PSR/GnPs at 15 vol. % of silicone rubber content has higher electrical conductivity and mechanical strength as compared to PUE/LSR/GnPs blend system.
  • Publication
    Effect of printing parameters on tensile, dynamic mechanical, and thermoelectric properties of FDM 3D printed CABS/ZnO composites
    ( 2018-03-22)
    Yah Yun Aw
    ;
    Yeoh Cheow Keat
    ;
    Mohd Asri Idris
    ;
    Teh Pei Leng
    ;
    Khairul Amali Hamzah
    ;
    Shulizawati Aqzna Sazali
    Fused deposition modelling (FDM) has been widely used in medical appliances, automobile, aircraft and aerospace, household appliances, toys, and many other fields. The ease of processing, low cost and high flexibility of FDM technique are strong advantages compared to other techniques for thermoelectric polymer composite fabrication. This research work focuses on the effect of two crucial printing parameters (infill density and printing pattern) on the tensile, dynamic mechanical, and thermoelectric properties of conductive acrylonitrile butadiene styrene/zinc oxide (CABS/ZnO composites fabricated by FDM technique. Results revealed significant improvement in tensile strength and Young's modulus, with a decrease in elongation at break with infill density. Improvement in dynamic storage modulus was observed when infill density changed from 50% to 100%. However, the loss modulus and damping factor reduced gradually. The increase of thermal conductivity was relatively smaller compared to the improvement of electrical conductivity and Seebeck coefficient, therefore, the calculated figure of merit (ZT) value increased with infill density. Line pattern performed better than rectilinear, especially in tensile properties and electrical conductivity. From the results obtained, FDM-fabricated CABS/ZnO showed much potential as a promising candidate for thermoelectric application.
  • Publication
    Effect of silicone rubber on the properties of epoxy/recovered carbon black (rCB) conductive materials
    ( 2024-04)
    Pei Chee Leow
    ;
    Teh Pei Leng
    ;
    Yeoh Cheow Keat
    ;
    Wee Chun Wong
    ;
    Chong Hooi Yew
    ;
    Xue Yi Lim
    ;
    Kai Kheng Yeoh
    ;
    Nor Azura Abdul Rahim
    ;
    Voon Chun Hong
    The primary focus of this study is to investigate the effect of silicone rubber (SR) content on the mechanical, thermal, electrical conductivity, and morphological properties of epoxy/recovered carbon black (rCB) conductive material. The conductive material is used to produce the electrostatic discharge (ESD) tray for the electronic packaging industry. This study investigated the effect of silicone rubber content (0, 5, 10, 15, and 20 vol.%) on the properties of epoxy/SR/rCB conductive materials, with the rCB content fixed at 15 vol.% for its optimum electrical conductivity. The silicone rubber acts as a toughening agent for epoxy. Through the fracture toughness result, it can be identified that silicone rubber plays a role in improving the toughness properties of the epoxy/SR/rCB conductive material. The optimum results for mechanical properties were recorded at 5 vol.% SR. The addition of SR to the epoxy matrix enhances the electrical properties of the epoxy/SR/rCB conductive material. The effect of thermal aging on epoxy/SR/rCB conductive materials was also studied to determine the properties of the conductive material materials at high temperatures for a long period of time. After thermal aging, the mechanical, thermal, electrical conductivity, and morphological properties of the epoxy/SR/rCB conductive material were slightly reduced.
  • Publication
    The effect of the GNP-SDS loadings on the properties of the NRL/GNP-SDS composites
    ( 2020-07-09)
    Che W.M.
    ;
    Teh Pei Leng
    ;
    Jalilah Abd Jalil
    ;
    Yeoh Cheow Keat
    Stretchable conductive polymer composites (CPC) are fabricated by incorporating the conductive particles into the polymer matrix. In this paper, CPC was fabricated by incorporating the sodium dodecyl sulfate (SDS) modified graphene nanoplatelet (GNP) into natural rubber latex (NRL) by varying loading from 0phr to 9phr using a simple mechanical stirring method. The effect of the GNP-SDS loadings on the properties of the composites were study by investigated the crosslink density, tensile properties, morphology of the tensile fracture surface and electrical conductivity. The crosslink density of the composites shows a decreased trend. Then, due to the well dispersed GNP-SDS, the tensile strength increased but decreased at high filler loading caused by the agglomeration issue. The tensile modulus also increased with increasing filler loading due to the intrinsic high modulus of GNP and the reduction of chain mobility. However, the electrical properties of the composites improved as GNP-SDS loading increased and achieved a percolation threshold at 7phr.
  • Publication
    A comparative study of microwave welding using multiwalled carbon nanotubes and silicon carbide nanowhiskers as microwave susceptors
    ( 2024-10)
    Phey Yee Foong
    ;
    Voon Chun Hong
    ;
    Lim Bee Ying
    ;
    Teh Pei Leng
    ;
    Yeoh Cheow Keat
    ;
    Mohd Afendi Rojan
    ;
    Nor Azizah Parmin
    ;
    Subash Chandra Bose Gopinath
    ;
    Foo Wah Low
    ;
    Muhammad Kashif
    ;
    Nor Azura Abdul Rahman
    ;
    Sam Sung Ting
    ;
    Veeradasan Perumal
    Recently, microwave welding has arisen as an advanced joining method due to its versatility and rapid heating capabilities. Among others, microwave susceptors play a crucial role in microwave welding, as different classes of microwave susceptors have distinct microwave heating mechanisms. In this work, polypropylene (PP) was utilized as a thermoplastic substrate and two types of microwaves susceptors, namely multiwalled carbon nanotubes (MWCNTs) and silicon carbide nanowhiskers (SiC NWs), were studied for microwave welding. The susceptor was first dispersed in acetone to form susceptor suspension. Next, the susceptor suspension was deposited onto the targeted area on substrate and paired with another bare PP substrate. The paired sample was then exposed to 800 W microwave radiation in a microwave oven. Afterward, the welded joint was evaluated using a tensile test and scanning electron microscopy to determine its joint strength and cross-section microstructure. The results showed that the joint strength increased as the heating duration increased. The welded joint formed using MWCNTs achieved a maximum strength of 2.26 MPa when 10 s was used, while the SiC NWs-formed welded joint achieved a maximum strength of 2.25 MPa at 15 s. This difference in duration in forming a complete welded joint can be attributed to the higher microwave heating rates and thermal conductivity of MWCNTs. However, increasing the heating duration to 20 s caused severe deformation at the welded joint and resulted in low joint strength. Overall, this study highlights the significance of understanding the microwave heating mechanism of different susceptors and provides essential insight into the selection of a microwave susceptor for microwave welding.
  • Publication
    Comparison study: The effect of unmodified and modified graphene nano-platelets (GNP) on the mechanical, thermal, and electrical performance of different types of GNP-filled materials
    ( 2021-09-01)
    Ka Wei K.
    ;
    Teh Pei Leng
    ;
    Yeoh Cheow Keat
    ;
    Hakimah Osman
    ;
    Sullivan M.
    ;
    Voon Chun Hong
    ;
    Lim Bee Ying
    ;
    Mohamad Syahmie Mohamad Rasidi
    Graphene nano-platelet (GNP) nano-fillers were successfully covalently functionalized with carboxylic and epoxide groups as proven by Fourier-transform infrared spectroscopy. This paper reports the effect of unmodified and modified GNP nano-fillers on the mechanical, thermal, and electrical performance of GNP-filled materials. The results show that the mechanical properties of GNP-filled materials were enhanced with a modified GNP nano-filler. Among the GNP-filled materials, the modified epoxy/NR/GNP compatibilized material shows higher flexural and toughness properties. The modified GNP nano-filler has reduced the thermal stability of the modified compatibilized material. This is because the oxygen-containing groups (C–O–C and –COOH) on the surfaces of modified GNP nano-fillers have lower thermal stability; which accelerates the thermal decomposition of the modified material. Modified compatibilized material shows higher electrical conductivity than the unmodified compatibilized material. X-ray diffraction results proved that d-spacing of modified GNP nano-fillers in modified compatibilized material was shortest when compared to unmodified GNP nano-fillers in unmodified compatibilized material, thus, allowing more electrons to travel at a faster rate through the conductive pathways.
  • Publication
    Dielectric and mechanical properties of PLA-carbon composites
    ( 2024-04)
    Mathanesh Thangarajan
    ;
    Yeoh Cheow Keat
    ;
    Teh Pei Leng
    ;
    Wee Chun Wong
    ;
    Chong Hui Yew
    ;
    Kang Zheng Khor
    ;
    Nor Azura Abdul Rahim
    ;
    Voon Chun Hong
    This study focuses on the development and characterization of Carbon-based Polylactide (PLA) composites for 3D printer filaments. The aim is to enhance the electrical and mechanical properties of PLA by incorporating recovered carbon black (RCB) in different mesh sizes (500, 1000, 1500, and 2000 mesh). Electrical impedance spectroscopy and dielectric constant measurements were performed to investigate the electrical properties of the composites. Results showed that the addition of RCB increased the dielectric constant, with values ranging from 2.5 to 7.1, indicating improved electrical performance. Scanning electron microscopy (SEM) analysis revealed the dispersion of carbon particles within the composites, enhancing their electrical conductivity. The effect of RCB particle size on electrical properties was also explored, with smaller particle sizes (2000 mesh) resulting in the highest conductivity of 6.2 S/m. Tensile testing demonstrated that the addition of RCB increases the tensile strength of PLA, with values ranging from 28.6 MPa to 47.2 MPa, and the elastic modulus, ranging from 832 MPa to 1.56 GPa, depending on the mesh size. The optimal combination of RCB content and mesh size resulted in a composite with a tensile strength of 43.8 MPa. Overall, this research provides insights into the development of Carbon-based PLA composites with improved electrical and mechanical properties.
  • Publication
    Comparison between natural rubber, liquid natural rubber, and recycled natural rubber as secondary matrix in epoxy/natural rubber/graphene nano-platelet system
    (Springer International Publishing, 2023)
    K. W. Kam
    ;
    Teh Pei Leng
    ;
    Yeoh Cheow Keat
    A comparison is made between the effects of natural rubber (NR), liquid natural rubber (LNR), and recycled natural rubber (rNR) in the filled epoxy systems on the physical, mechanical, thermal, and electrical performances of filled epoxy systems. The results show that flexural strength and modulus values were improved. The toughness properties of the filled epoxy system were enhanced with NR phases (72 MPa, 2317 MPa, 4.2 MPa. m1/2), as compared to those with LNR (55 MPa, 2100 MPa, 3.2 MPa. m1/2) and rNR (52 MPa, 2000 MPa, 2.3 MPa. m1/2) at 5 vol.%. Scanning electron micrograph (SEM) analysis revealed that the particle sizes of NR phases dispersed within the epoxy matrix were smaller and more uniform (0.29-1.65 μm) as compared to those with LNR (0.64-3.57 μm) and rNR (≥250 μm) phases. The incorporation of NR, LNR, and rNR phases improved the thermal stability of the filled system. This is attributed to more heat energy being needed to overcome good interfacial bonding between epoxy matrices and the small NR phases. X-ray diffraction analysis results showed that the filled epoxy/NR/GNP system has higher 2θ values, indicating that d-spacing in GNP nano-fillers has the closer distance. Electrical bulk conductivity values of filled epoxy/NR/GNP systems were the highest, 4.50 x 10-3 1/Ω. cm at 20 vol.%. Small NR phases acted as elastomer spacers, which provided better GNP packing efficiency and realigned the GNP nano-fillers to form more effective conductive pathways for electron transport.
  • Publication
    Comparison study between recovered carbon black and commercial carbon black filled epoxy conductive materials
    ( 2024-01-01)
    Ooi H.M.
    ;
    Teh Pei Leng
    ;
    Yeoh Cheow Keat
    ;
    Wong W.C.
    ;
    Yew C.H.
    ;
    Lim X.Y.
    ;
    Yeoh K.K.
    ;
    Nor Azura Abdul Rahim
    ;
    Voon Chun Hong
    Waste tire management and recycling have grown to be significant issues because they bring up a global environmental concern. Thus, turning recycled waste tires into useful products may help tackle the environmental issue. This research aims to study and compare the effect of recycled carbon black (rCB) and commercial carbon black (CB) at certain 15 vol. % of filler loading on the mechanical, thermal, morphology and electrical properties of epoxy/CB composites. For this project, epoxy resin, diethyltoluenediamine (DETDA), recovered carbon black (rCB) and commercial carbon black (CB) graded N330, N550, N660 and N774 were mixed and compared accordingly to the formulation determined. The CB content was dispersed in the epoxy matrix using the mechanical mixing technique. The distribution and dispersion of CB in the epoxy matrix affect the characteristics of the conductive composites. rCB content at 15 vol% was selected at fixed content for comparison purposes due to the optimum value in electrical conductivity results. The flexural strength results followed the sequence of rCB>N774>N660>N550>N330. As for electrical conductivity results, epoxy/N330 exhibited the highest conductivity value, while the others achieved a magnitude of X10-3 due to the highest external surface area of N330. In terms of thermal stability, epoxy/N330 and epoxy/N774 were slightly more stable than epoxy/rCB.
      1
  • Publication
    Microwave welding of thermoplastic using silicon carbide nanowhiskers as susceptor effect of heating duration
    ( 2024-06)
    Phey Yee Foong
    ;
    Voon Chun Hong
    ;
    Lim Bee Ying
    ;
    Teh Pei Leng
    ;
    Yeoh Cheow Keat
    ;
    Mohd Afendi Rojan
    ;
    Nor Azizah Parmin
    ;
    Subash Chandra Bose Gopinath
    ;
    Foo Wah Low
    ;
    Muhammad Kashif
    ;
    Nor Azura Abdul Rahman
    ;
    Sam Sung Ting
    ;
    Veeradasan Perumal
    Microwave welding is becoming more popular than conventional joining methods due to its advantages such as rapid and localised heating as well as applicable to components with complicated geometry. Previously reported susceptor, such as carbonaceous materials and conductive polymers, are toxic and the welding process involving these susceptors is time-consuming. Because of its exceptional microwave absorption and biocompatibility, silicon carbide nanowhiskers (SiCNWs) was employed as the microwave susceptor for microwave welding. Microwave welding in this study comprises of only three simple steps: SiCNWs suspension preparation, SiCNWs application and microwave heating. The weld strength of welded joint was then characterised using tensile test and energy dispersive x-ray spectroscopy equipped scanning electron microscopy (EDS-SEM) to study its mechanical properties and cross-section microstructure. The influence of microwave irradiation time was studied in this study, and it is found that the weld strength rose with the extension of microwave irradiation time, until a maximum weld strength of 1.61 MPa was achieved by 17 s welded joint. The development of SiCNWs reinforced PP nanocomposite welded joint layer is responsible for the enhanced weld strength. Prolonged heating duration may also result in flaws such as void formation at the welded joint, which subsequently lowered the weld strength to 0.60 MPa when the heating duration was extended to 20 s. In sum, a strengthen welded joint can be formed with rapid microwave heating under the proper control of heating duration.
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