Oriented Poly(lactic acid)/Carbon Nanotube Composite Tapes with High Electrical Conductivity and Mechanical Properties

Oriented poly(lactic acid) (PLA)/multiwall carbon nanotube (MWNT) tapes are prepared by solid-state drawing. These tapes showed significant morphological, mechanical and electrical property changes after drawing, with polymer crystallinity, nanotube dispersion and alignment being improved. Interestingly, the presence of the MWNTs perturbed the orientation of the crystalline polymer chain domains. Drawing lowered the electrical conductivity and increased the percolation threshold of the nanocomposites, but micromechanical analysis showed that it greatly improved the reinforcing efficiency of the MWNTs. This resulted in an overall good balance with one of the best compromises in terms of high mechanical properties and electrical properties for conductive polymer composite tapes.