Electrospun polyamide 4.6 nanofibrous nonwovens: Parameter study and characterization

Abstract

The aliphatic polyamide 4.6 (PA 4.6) has unique properties compared to the commonly used polyamides 6 (PA 6) and 6.6 (PA 6.6). The purpose of this paper is to produce uniform and reproducible nanofibrous PA 4.6 structures. Therefore, a mixture of the solvent formic acid and the nonsolvent acetic acid is used to dissolve and electrospin the PA 4.6. First the steady-state behaviour of the process and the boundary limits of the solution parameters needed for steady-state electrospinning are investigated. Subsequently, the effect of several solution and process parameters on the fibre morphology is examined, using microscopic techniques and thermal analysis. The polyamide concentration is found to be the dominant parameter affecting the fibre diameter and morphology. Furthermore, tensile tests are performed on upscaled nanofibrous structures and electrospun under optimised steady-state conditions. It is shown that the PA 4.6 nanofibrous structures, compared to nanofibrous nonwovens of PA 6 and PA 6.6, have a higher stress and strain at break. Copyright © 2012 Bert De Schoenmaker et al.