The Electrical Conductivity Study Of Conductive Polymer Composite Under Creep And Temperature Shock

Conductive polymer composites have been widely used in many fields in recent20years. It isfound that conductive properties of short stainless steel fiber filled polymer composites are betterthan those of graphite filled polymer composites, therefore, the electrical conductivity of CNT/SSF/PA6under creep and temperature shock is studied in this paper. The main contents aresummarized as the following,(1)The electrical conductivity of CNT/SSF/PA6under creep is studied. The resistance of thematerial as well as the loading and displacement under creep are measured by experiment method.Then the microstructure of the sample is observed by scanning electron microscope, and we findthat interfacial fracture takes place in the material.(2) The electrical conductivity of CNT/SSF/PA6under temperature shock is investigated. Theexperiment of temperature shock is designed as: i. Take the sample into liquid nitrogen suddenly; ii.Take the sample out of the liquid nitrogen quickly. The resistance of the material is measured byexperiment method, and we find that the resistance of the sample increases with the decrease of thetemperature. It is also found that interfacial fracture takes place in the material.(3) Study on a new criterion of interfacial fracture of particle/polymer composites. Thefracture of interface between particles and matrix is one of the dominant mechanisms leading to thefailure of particulate-reinforced composites. Owing to viscosity in polymeric matrix, the interfacialfracture is determined by the local strain at interface. The interfacial fracture of an elastic sphericalinclusion embedded in an infinite visco-elastic matrix is analyzed based on the principle of energy.Calculation is carried out on the work done by external loads, and the variation of strain energy ofmatrix and the inclusion, as well as the surface energy just before and just after interfacial fracture,and then a new interfacial strength model is proposed in terms of local critical strain. Based on thisstudy, the interfacial fracture of an elastic fibre inclusion embedded in an infinite visco-elasticmatrix is analyzed.The results obtained in the present work are valid for the study and design of conductivepolymer composites.