Polypropylene/carbon black (PP/CB) and PP/CB/multiwalled carbon nanotube (PP/CB/MWCNT) composites were fabricated by solid and foam injection molding, with the goal of enhancing the electrical conductivity of the composites while decreasing the cost of the final product. The foaming behavior and through-plane (T-P) electrical conductivity of the composites were characterized and analyzed. Cell growth increased the interconnection of the conductive fillers, changed the filler orientation, and enhanced the T-P electrical conductivity of the composites. Under appropriate processing conditions (200°C melt temperature, 70 cm3/s injection flow rate, and 5% void fraction), the T-P electrical conductivity of the foam PP/CB composites was 5 orders of magnitude higher than that of the solid composites (from 5.877 × 10−12 S/m to 1.010 × 10−7 S/m). Moreover, the T-P electrical conductivity values of the PP/CB and PP/CB/MWCNT were compared at the same conductive fillers content (15 wt%). The results showed that the T-P electrical conductivity of the PP/CB/MWCNT composites was far higher than that of the PP/CB composites by almost five orders of magnitude because the MWCNT acted as a bridge between CB particles, and a unique geometric shape was formed in the system. The T-P electrical conductivity of the foam PP/CB/MWCNT composites with 15 wt% carbon fillers was higher than that of the solid PP/CB composites with 20 wt% carbon fillers. This study reveals that the effect of foaming and the addition of hybrid fillers can improve the T-P electrical conductivity of plastic products, which is very important for the development of lightweight conductive plastics.

中文翻译：

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具有微孔结构和混合填料的注射成型轻质高电导率复合材料

聚丙烯/炭黑（PP/CB）和PP/CB/多壁碳纳米管（PP/CB/MWCNT）复合材料通过固体和泡沫注塑成型，目的是提高复合材料的导电性，同时降低成本。最终产品。表征和分析了复合材料的发泡行为和贯穿面（TP）电导率。细胞生长增加了导电填料的互连，改变了填料的取向，增强了复合材料的 TP 电导率。在合适的加工条件下（200°C熔体温度、70 cm3/s注射流速和5%空隙率），泡沫PP/CB复合材料的TP电导率比固体复合材料高5个数量级（从 5.877 × 10−12 S/m 到 1.010 × 10−7 S/m）。而且，在相同的导电填料含量 (15 wt%) 下，比较了 PP/CB 和 PP/CB/MWCNT 的 TP 电导率值。结果表明，PP/CB/MWCNT复合材料的TP电导率远高于PP/CB复合材料近五个数量级，这是因为MWCNT充当了CB颗粒之间的桥梁，并且具有独特的几何形状。系统中形成。含15wt%碳填料的泡沫PP/CB/MWCNT复合材料的TP电导率高于含20wt%碳填料的固体PP/CB复合材料。本研究揭示了发泡作用和混合填料的加入可以提高塑料制品的TP导电性，这对轻质导电塑料的发展非常重要。