Properties of polypropylene/multiwall carbon nanotube composite films prepared by microlayer extrusion

Abstract

Polypropylene/multiwall carbon nanotube composites with 1, 9, 81, and 729 layers were prepared with a novel microlayer extrusion technology. The influences of multiwall carbon nanotube dispersion and orientation on crystallization behavior, mechanical properties, and thermal stability of composites were investigated. The results indicated that homogeneous dispersion and improved multiwall carbon nanotube orientation in matrix were obtained with more layers. The tensile strength, Young’s modulus, and elongation at break of polypropylene/multiwall carbon nanotube composites with 729 layers increased by 77%, 78%, and 149%, respectively, compared with 1 layer composites. The 81 and 729 layer samples displayed obvious double yielding points on the stress–strain curves. Furthermore, thermogravimetric analysis showed that the composites with more layers exhibited better thermal stability than the 1 layer composites. These results suggest that multiwall carbon nanotube dispersion and orientation in a matrix can be effectively improved through microlayer extrusion.