Ultrastrong and excellent dynamic mechanical properties of carbon nanotube composites

High performance carbon nanotube (CNT)/polyimide (PI) composites with high CNT fraction and high degree of orientation of CNTs were fabricated by infiltration-winding method by coupling PI solution with continuous horizontal aligned few walled CNT film transferred from the vertically CNT array using layer by layer assembly. Different CNT fractions of CNT/PI composites were obtained by tuning the concentration of PI solution. The static and dynamic mechanical properties of CNT/PI composites were investigated. The results show that the interaction between CNTs was greatly improved by the enhancement of contact area of CNTs through PI solution shrink the CNT film, thus the strength and modulus of CNT/PI composites were significantly enhanced up to 3.9 GPa and 182 GPa, respectively. The dynamic mechanical analysis (DMA) results showed that the glass transition temperature of PI increased over 130 °C up to 325 °C due to the nanometer interface interaction between CNT and PI resin matrix. The CNT/PI composites also demonstrated excellent structure stability. The excellent mechanical properties make the composites promising for high temperature structural and functional materials for aerospace applications.