Chemical degradation and stability of oxygen plasma-treated poly(hexamethylene adiamide) fabric meshes
Résumé
Poly(hexamethylene adiamide) or nylon 6,6 fabrics with different mesh sizes were exposed to oxygen plasma ignited in a reactive ion etching (RIE) configuration to achieve surface nanostructures and nanoporosity and improved wettability for textile and filtration applications [1]. The effects of plasma power and irradiation time on the samples were observed by performing experiments using constant irradiation time in varying power and using constant power in varying irradiation times. The surface modification was determined by employing characterizations such as contact angle measurements, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). Results showed improved wettability of nylon 6,6 fabrics after the plasma treatment. The FTIR spectra of all the treated samples exhibited decreased transmittance of the amide and carboxylic acid groups due to surface etching and surface nanostructures that were observed for the plasma-treated samples on the SEM data. The etching of the surfaces was enhanced for higher power plasma treatments. DSC data showed that the plasma treatment decreased the samples' crystallinity and in consequence increased the amorphous phase of the samples. Surface chemistry showed that the effects of the plasma treatment on the samples have no significant difference for all the mesh sizes. However, surface morphology showed that the porosity was the same for all the mesh sizes but samples with larger mesh sizes exhibited enhanced etching as compared to the samples with smaller mesh sizes. The plasma-modified nylon 6,6 samples were then subjected to degradation and stability studies by exposing them to different liquids such as deionized water, alkali, acid, ionic, and organic solvents. The stability tests adapted this the study was a modified protocol defined by Malavasi et al. [2]. The degradation and stability of the material were evaluated by contact angle measurements and FTIR for a specified period of time. Results showed that the fabric exhibited a general increase in chemical resistance to most of the solvents. However, the degradation of the material varies depending on the solvent used.