Ultrastrong carbon nanotube/ bismaleimide composite film with super-aligned and tightly packing structure

An ultra strong bismaleimide (BMI)/carbon nanotube (CNT) composite film with super-aligned and tightly compacted structure was prepared from CNT array by combining the techniques of polymer spraying, stretching and hot pressing. The BMI curing process was optimized and the obtained stretched-BMI/CNT film exhibited a tensile strength and modulus up to 4.50 and 275 GPa, respectively, with a CNT load reaching up to 65.5wt% and an electrical conductivity of 2.45 × 104 S/m. It was demonstrated that the super-aligned and tightly packing structure of CNT film, mainly resulting from the straightened long double-walled CNT structure, good wetting property of BMI solution with CNT film, and high CNT alignment degree. Based on the experimental characterizations for CNT films, a polymer-CNT interpenetrating network mode was proposed to illustrate the unique properties and microstructure of this BMI/CNT film.