Multifunctional Interphases: Percolation Behavior, Interphase Modification, and Electro-Mechanical Response of Carbon Nanotubes in Glass Fiber Polypropylene Composites

Carbon nanotube dispersions have been immersedin a maleated polypropylene film former system andapplied to insulating glass filament yarns compatible to polypropylene matrix. The percolation threshold can be reached below 0.5 wt% carbon nanotubecontent. In order to achieve a homogeneous multifunctional interphase, the average sizing thickness must be above 450 nm tailored during a coating process by varying the solid content of the sizing. The temperature and the velocity of the coating process have a great impact on the volume resistivity of the multifunctional interphase. Electro-mechanical behavior as sensors in unidirectional composites containing 50 vol% glass fiber reinforcement is monitored during tensile and compression loading. The largest electrical sensitivity is achieved for tensile loading in the axis of fibers.