Research On Conductive Properties Of Carbon Black/Plant Fiber Filled PP Composites

Conductive polymer compositeshavebecome ahotspot inrecent studies ofelectromagnetic shielding composites for its low cost and excellentprocessing performance.As the conductive carbon black (CB) with respect to a lower percolation threshold，so itiswidely used in the experiments and actual production.In this article I study the conductivityof carbon black/sisal fiber (SF) firstly and then discussetheconductivity properties of SF/CB/PPternary composites.Then, the paper studies the electromagnetic shielding properties ofmetal mesh laminated PP composites,drawn just build internal conductive network in thecomposite material, the material can be achieved electromagnetic shielding characteristics.Accordingly designed two ways to build conductive networks: First, by changing the shape ofsisal fiber filler, such as the use of powder,fiber,mesh construct different internal conductiveframe,the second is by changing the particle size of the substrate and thus PP change the sizeof the conductive mesh construct different conductive networks.The results showes that:CB in PP percolation threshold of15%, adding sisal can effectively reduce thepercolation threshold to about10%. When the total content of CB and40%SF, the time tochange the content of CB, CB mass fraction increases as the shielding performance of thecomposite material has increased significantly, decreased resistance, and when the CBcontent of30%Shielding Composites basically to achieve shielding effectiveness of30dBvalue in each band. Also with increasing CB mass fraction, the resistivity drop impactstrength of the composites and materials have the same trend,but are gradually increasingflexural and tensile strength.Contrast to fiber was not added,was added lignin,4mmSF and60#jute theelectromagnetic shielding performance of each10%composites obtained,60#jute shieldingeffectiveness of the material added to increase the maximum,increased about8dB, lignin wasby about6dB, followed by adding SF, increased by about4dB,without added plant fibercomposite shielding effectiveness was worst. Description CB in the composite mesh structureappears to be able to maximize the shielding properties of composites.With the variationof PP particle size,electromagnetic shielding properties of thecomposites increased with the diced speed first and then decreased.When pelletizer ratereached25r/min, the electromagnetic shielding properties of this composites was worst,whenthe rate reached40r/min pelletizer shielding properties of composite materials was best. Theelectromagnetic shielding performance in each bandof10%CB is up to20dB or more.