Preparation and properties of polyimide/carbon nanotube composite films with electromagnetic wave absorption performance

Abstract The polyimide (PI)/carbon nanotube (CNT) films including 3,3′,4,4′‐biphenyl tetracarboxylic dianhydride (BPDA), p ‐phenylenediamine ( p ‐PDA), and CNTs were prepared, which have prominent electromagnetic (EM) wave absorption performance. Experimental analyses of the mechanical properties, thermal stabilities, coefficient of thermal expansion (CTE), the glass transition temperature (T g ), and EM parameter revealed the beneficial effects of the CNTs on the resulting composite films. In particular, when the content of CNTs is 6 wt%, the film shows the highest EM wave absorption performance, which exhibits the effective absorption bandwidth of 2.72 GHz with the matching thickness of only 2.0 mm. These results indicate that PI‐based films have a certain potential application in the area of EM wave‐absorbing materials.