The paper presents a method of producing nanopaper from a commercial P84 NT polyimide (PI) using an electrospinning and fiber heat fusing approach. The polyimide nanofibers were made by electrospinning of 20% concentration P84 NT PI. Then the nonwoven nanofibers were vacuum heat fused at 330 degrees C to make nanopaper. The diameter of nanofibers ranged from 280 to 510 nm. The microtensile test was conducted using a special test specimen frame to measure tensile modulus and strength. The measured modulus and strength were 871 MPa and 57.1 MPa, respectively, for randomly (250 RPM) oriented fibers. These values doubled by increasing the fiber alignment (drum speed of about 2000 RPM). Furthermore, the fracture strain ranged from 15.8% to 33% depending on the fiber fusing temperature. The data in literature shows low fracture strain (5% or less) and higher modulus and strength of the nanopaper than that is in the present results. (C) 2013 Elsevier Ltd. All rights reserved.