טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentMarat Drubetsky
SubjectElectrically Conductive Composite Materials
DepartmentDepartment of Materials Science and Engineering
Supervisor Professor Emeritus Siegmann Arnon (Deceased)


Abstract

  Electrical conductive plastics are being used for modern high-tech applications such as electromagnetic, radio frequency interference and conductive composites for parts of fuel cells.  Relatively high values of electrical conductivity (~101 S/cm) may be achieved in such systems by compounding polymers (10-12 - 10-18 S/cm) with conductive fillers, such as carbon black, carbon fibers and metal fibers (102 and 106 S/cm).

  Fillers are to be added at a level above certain critical content - “percolation threshold”, for the system to become conductive. Attempts to reduce filler content have been made by means of: selecting preferred additives shape, proper matrix polymers and application of certain processing conditions.

   Presently multi-filler systems, compounded in a co-rotating intermeshing twin extruder and then injection molded into standard ASTM mold were investigated, expecting reduction of percolation filler content and highly conductive composites. The electrical conductivity of polymer based composite systems containing both, carbon black (CB) and carbon fibers (CF) were studied. Rheology, structure, morphology and filler degradation investigations were conducted to better understand the composition - structure - property relationships for the CB/CF filled systems. Different polymer matrices were used and synergistic effects in overall conductive network formation, in spite of shadowing by the filler degradation phenomenon, were detected.