An innovative method to reduce the energy loss of conductive filler/polymer composites for charge storage applications

Foam injection molding of polypropylene/stainless steel fiber composites for efficient EMI shielding

“…The percolation threshold was found to be 0.85 vol.% for SIM composites, using procedure of [37]. The percolation threshold of SIM composites is known to be much higher than that of solid compression-molded samples [18,19]. It is also reported that the conductivity of SIM samples beyond the percolation threshold is lower than that of the solid compression-molded samples at the same SSF content [18,19].…”

“…The percolation threshold of SIM composites is known to be much higher than that of solid compression-molded samples [18,19]. It is also reported that the conductivity of SIM samples beyond the percolation threshold is lower than that of the solid compression-molded samples at the same SSF content [18,19]. The major reason for these differences stems from the difference in the state of orientation in injection-molded and compression-molded samples.…”

“…Particularly, the weight reduction of CPCs is very desirable in aerospace and automotive industries. CPCs are usually processed using injection molding wherein further challenges are introduced as it results in (a) significant fiber breakage [16][17][18], (b) anisotropic electrical conductivity [16,19], and (c) higher percolation thresholds [18].…”

Electrical and dielectric properties of foam injection-molded polypropylene/multiwalled carbon nanotube composites

“…Also, TEM micrographs of solid and foam injection-molded PP-1.26 vol.% MWCNT are depicted in Figure 2b-c, respectively. It is seen that in the solid injection-molded samples, the MWCNTs were forced to partially align in the machine direction (Figure 2b) due to the applied shear stresses in the flow direction during the melt injection [11,12,14]. In the foamed injection-molded samples, the MWCNTs were confined between the adjacent cells, lying in the cell walls and struts (Figure 2c).…”

“…They reported ε'=30 and tan δ=0.07 for PP-0.34 vol.% MWCNT foams with a relative density of 0.45 prepared using a batch-type foaming process [13]. contribute to the enhancement of the dielectric properties of polystyrene/MWCNT composites [14]. Ameli et al have also shown that the physical foaming in injection molding alters the microstructure, resulting in a lowered electrical percolation threshold, and enhanced electrical conductivity of PP-carbon fiber composites [11,12].…”