AVS 49th International Symposium
    Nanotubes: Science and Applications Topical Conference Tuesday Sessions
       Session NT-TuA

Paper NT-TuA3
Carbon Nanotube/ Polymer Composite: Mechanical and Electrical Properties

Tuesday, November 5, 2002, 2:40 pm, Room C-209

Session: Nanotubes: Mechanical Properties, NEMS
Presenter: H.Z. Geng, University of North Carolina at Chapel Hill
Authors: H.Z. Geng, University of North Carolina at Chapel Hill
B. Zheng, Duke University
H. Shimoda, University of North Carolina at Chapel Hill
J.L. Liu, Duke University
O. Zhou, University of North Carolina at Chapel Hill
Correspondent: Click to Email
Carbon Nanotubes with elastic modulus ~1Tpa, and fracture strain ~5~10%, is interesting as filler for mechanical enhancement. Due to the poor dispersion and poor interfacial bonding between nanotube and polymer matrix, expected enhancement in mechanical properties by adding nanotube to polymer has by and large not been demonstrated. In this talk we present our results by using fluorinated nanotubes (F-SWNT). Differential scanning calorimetry (DSC) results show that our composite is macroscopically uniform. Tensile stress-strain curve and dynamic mechanical analysis (DMA) results show a significant enhancement of mechanical properties by adding only a few percentage of F-SWNTs. Carbon black particle and carbon fiber filled polymer composites attract a lot of interest due to their Positive Temperature Coefficient (PTC) effect at percolation and therefore their potential application as temperature or current sensors. With large aspect ratio Carbon Nanotubes may offer some advantages over carbon black and carbon fiber, because percolation threshold is believed to be inverse of aspect ratio. In this talk we present our recent results on the dependence of percolation threshold on average length of nanotubes in CNT/polymer composites. Temperature effects on conductivities of composites at their percolations will also be presented.