Preparation and characterization of thermally stable polyimide membranes by electrospinning for protective clothing applications

Abstract

The aim of the present study was to obtain high-performance materials for heat and flame protective clothing. Therefore, hybrid membranes were prepared using Kevlar as support and aromatic polyimide nanofibers as a protective coating. The exceptional performances of the prepared membranes were highlighted by selected indicators: high thermal stability, fire resistance and improvement in air permeability without modifying drastically the water vapor transmission rate properties. Attenuated total reflectance Fourier transform infrared and 1H nuclear magnetic resonance spectroscopy were employed to confirm polyimide formation. The ability of polyimide to form fibers was investigated by rheological measurements and scanning electron microscopy, respectively. Thermal degradation was studied using thermogravimetric analysis and a microscale combustion calorimeter. The transport properties of the materials were examined by air permeability, water vapor transmission rate and water resistance. It was shown that transport properties of the modified Kevlar membranes could be controlled by varying the spinning time of polyimide solution. Moreover, by annealing the modified Kevlar weavings at 260℃, the structural integrity and transport properties were not affected, whereas a higher resistance to water was found.