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.

Colorful Hydrophobic Poly(Vinyl Butyral)/Cationic Dye Fibrous Membranes via a Colored Solution Electrospinning Process

“…The electrospun (e-spun) nanofibers can be collected as nanofiber membrane (NFM) and have been found in various applications such as tissue engineering scaffolds, [5, 6] drug delivery, [6, 7] wound dressing, [8, 9] high efficiency particulate air filter, [10] flexible nano-optoelectronic devices, [11, 12] nanosensors, [12, 13] protective clothing, [14, 15], and so on. However, the typical e-spun NFM usually appears white, which is the common color of polymers and mainly due to the physical phenomenon of light scattering [16, 17].…”

Physical and thermal properties of poly(ethylene terephthalate) fabric coated with electrospun polyimide fibers

“…The air permeability values decrease with increasing electrospinning times in the case of PET/PI-2 when compared with PET/PI-1 for 30 and 60 min, as observed in other studies. 29 An opposite effect can be observed for PET/PIs/15 min samples where PET/PI-2 had a higher value for air permeability when compared with PET/PI-1. Probably in the case of PET/PI-1/15 min the covering of PET substrate is denser when compared with PET/PI-2/15 min, due to the difference in the average fiber diameters of these PIs (Figure 3).…”

“…These electrospun fibers can stop or reduce the water absorption of PET woven fibers by filling the void spaces between the yarns and the existing cracks. 29 …”

Waterproof and Breathable Electrospun Nanofibrous Membranes

“…Except for commonly‐used PVDF and PS, researchers also utilized other hydrophobic polymers as raw materials for preparing W&B membranes, such as polyimide (PI), PP, PES, and so on . Serbezeanu et al . prepared thermally stable electrospun PI membranes on Kevlar weavings and annealed the hybrid membranes at 260 °C to improve the water resistance.…”