Properties Study Of Thermoplastic Conductive Composites Prepared By Spacial Confining Forced Network Assembly

Polymer matrix composite is a functional material that is mixed with polymer matrix and different filler.It has electrical conductivity,thermal conductivity,or flame retardancy.Thermoplastics are the most widely used plastics in people’s daily life.It has many characteristics such as repeated melting and solidification,easy processing and easy forming.Therefore,thermoplastic composites are also characterized by corrosion resistance,light weight and reusing.It has been widely applied in the field of manufacturing antistatic,electromagnetic interference(EMI),conductive and thermal conductive products,and has attracted the attention of researchers.At present,the most commonly used method of constructing composite conductive network is self assembly.But the self assembly conductive network is not strong enough because of self assembly force,so the packing spacing is not controllable,and the mesh is not dense enough.It can make the polymer have conductivity,but its conductivity is much lower than that of the conductive filler itself,but it still can’t reach the high conductivity state.Based on the above analysis,the mechanism and method of preparing conductive composites based on SCFNA method are discussed in this paper.Thermoplastic polymer based conductive composites were prepared by experiments.The samples of single filler,two element filler,shape,concentration and thickness of different filler were prepared by experiment,and the electrical conductivity and the construction of conducting network were tested.The applicability of SCFNA method in thermoplastic matrix is demonstrated.The main research contents include:(1)The percolation concentration of carbon fiber/polypropylene composites prepared by SCFNA method is reduced to 4.2wt%.The electrical conductivity of the new composite material is greatly improved,which is 4 orders of magnitude higher than that of the conventional method.The scale graphite/polypropylene composites were prepared by the SCFNA method.The maximum electrical conductivity of the composite material was 200 times higher than that of the conventional method.The applicability of SCFNA method to thermoplastic matrix is verified.It is proved that the density of conductive network is an important factor affecting conductivity.Also studied the effect of degree of force is assembled,and the filler concentration of the microstructure of the material of the conductive composite.(2)The SCFNA method can act as a mandatory assembly for the conductive network formed by different forms of conductive fillers.However,the shape of filler will affect the number of effective contact points in conductive network,thus affecting the electrical conductivity.Fibrous fillers are more likely to form a dense network.(3)The conductive composites of two yuan packing system were prepared by SCFNA method.In the 10wt%carbon fiber/polypropylene composites,the graphene with mass fraction of 0.25wt%and 0.5wt%was added.It is found that a small amount of nano filler is added to the composite material,and the electrical conductivity can be greatly improved.Therefore,composite materials with low filling and high conductivity can be prepared.