Highly filled multilayer thermoplastic/graphene conducting composite structures with high strength and thermal stability for electromagnetic interference shielding applications

Abstract

Polyvinyl chloride (PVC)/graphene and poly(methyl methacrylate) (PMMA)/graphene nanocomposites were made by solution casting technique with graphene weight fractions of 1, 5, 10, 15, and 20%. Multilayer structures of the composites were made by hot compression technique to study their electromagnetic interference shielding effectiveness (EMI SE). Tensile strength, hardness, and storage modulus of the nanocomposites were studied in relation with graphene weight fraction. There has been a substantial increase in the electrical conductivity and EMI SE of the composites with 15-20% filler loading. Differential thermal analysis of the composites shows improved thermal stability with an increase in graphene loading. PMMA/graphene composites have better thermal stability, whereas PVC/graphene composites have superior mechanical properties. About 2 mm thick multilayer structures of PMMA/graphene and PVC/graphene composites show a maximum EMI SE of 21 dB and 31 dB, respectively, in the X band at 20 wt % graphene loading. Figure 6. SEM images of the tensile fractured surface of (a) PMMA/20 wt % graphene composite, (b) PVC/20 wt % graphene composite, (c) ultimate tensile strength of polymer/graphene composites, (d) Young's modulus of polymer/graphene composites. [Color figure can be viewed at wileyonlinelibrary.com] ARTICLE WILEYONLINELIBRARY.COM/APP

Significantly enhanced the properties of PE/GO composites with segregated structures via two‐step compound

“…21 By virtue of the segregated structure formed in LLDPE matrix, the MGO can effectively enhance electrical property of LLDPE matrix without additional reduction as shown in Figure 5a. Firstly, the volume resistance of the HDPE-MGO gradually decreased with the increasing of the MGO loadings due to the high contract area and conductivity, 24 the volume resistance is 6.23 ± 0.32 E, 4 2.65 ± 0.34 E, 3 3.84 ± 0.46 E 2 and 1.25 ± 0.09 E 2 ΩÁm at the adding loadings of MGO in 5, 10, 15, and 20 wt%, respectively. After diluting 10 times in LLDPE by meltmixed method and forming the segregated structure, the electrical property of LLDPE/HDPE-MGO reaches the antistatic level (volume resistance: 2.61 ± 0.15 E 7 ΩÁm) with the loading of 2 wt% MGO.…”

“…Electrically conductive polymer composites (CPCs) have attracted considerable academic and industrial attentions due to the easy processing, adjustable electrical properties, and low cost 1 . It has been widely employed in anti‐static materials, 2 electromagnetic interface, 3,4 sensor, 5 and conductors 6,7 . Actually, most of the ordinary host polymers are essentially insulating, after incorporating the conductive filler, the composites will exhibit an insulator/conductor transition when the conductive filler reach a critical value (percolation threshold: φ c ), where the conductive network get constructed.…”

Ionic liquids as dispersing agents of graphene nanoplatelets in poly(methyl methacrylate) composites with microwave absorbing properties

“…It was reported that multilayered structures constituted by absorbing composite layers can provide better EM radiation attenuation (decrease of RL) with outstanding broad bandwidth, which is attributed to the increase of multi‐reflection and scattering of the radiation between conductive layers 62,63 . These structures can be arranged as stacked layers with similar composition 22 or different compositions with different conductivity values 64 . The arrangement of the different layers also contributes for broadening the frequency range with improved EM attenuation 15 .…”

“…21 Joseph et al reported a conductivity of 10 −5 S m −1 and EMI SE of around 13 dB for the PMMA/ GNP composites containing 10 wt% of GNP and prepared by solution blending. 22,23 Zhang et al achieved EMI SE of around 3.5 dB with the addition of 2 wt% of GNP in PMMA by solution process. 24 Zakiyan et al also reported an EMI SE of around 3 dB with the presence of 3 wt% of GNP in the PMMA composite.…”

“…The conductivity increased four orders of magnitude when PS/PMMA blend was used as the matrix 21 . Joseph et al reported a conductivity of 10 −5 S m −1 and EMI SE of around 13 dB for the PMMA/GNP composites containing 10 wt% of GNP and prepared by solution blending 22,23 . Zhang et al achieved EMI SE of around 3.5 dB with the addition of 2 wt% of GNP in PMMA by solution process 24 .…”