Effect of Borax Decahydrate on Thermal Properties of Electrospun Nylon 6,6 Nanofibers

Abstract

Recent progress in polymeric material engineering, especially in the processing of materials in nanoscale, has constituted promising opportunities for generating nanostructured materials having various functionalities. Nano or micro sized inclusions incorporated into polymers improve their multifunctional properties such as flame retardancy, UV protection, self-cleaning, antistatic, mechanical strength and antimicrobial activities. Nanofiber technology (fiber diameter less than 1 micrometer) is under development for the preparation of novel materials in nano-scale with multifunctional properties. Electrospinning is an elegant method for producing nanofibers with high porosity and high spesicific surface area (Beachley, 2009). The electrospun nanofibers with superior properties can be obtained controlling the diameter and distribution of the fibers (Huang, 2011). Attempts have been made to incorporate inclusions into fibers to develop their flammability and thermal properties (Agwuncha, 2017). Polymers, for example, polyurethane, polyvinyl alcohol, polyacrylonitrile and polyamide, and their composites had been fabricated to develop the thermal stabilities of industrial products. Nylon 6,6 is one of the best-known polymers used in textile or other industries due to its high mechanical, physical and thermal properties. Nylon 6 and Nylon 6,6 are polyamides, which means they are molecules whose repeating units are linked by amide bonds. Some polyamides, such as silk, can be found naturally, but nylons are made in a lab. Nylon 6,6 is synthesized by polycondensation of hexamethylenediamine and adipic acid. Nylon 6,6 is flammable and also has dripping problem that limits its use in a wide range of applications. The aim of the present work is to improve the thermal properties of Nylon 6,6 (Polyamide PA66) electrospun nanofibers. Nylon 6,6 nanofibers were fabricated using electrospinning method via incorporation of Borax decahydrate (Na2B4O7.10H2O) into the polymer matrix. There have been no studies using this combination to fabricate a nanofibrous polymer. The surface morphology and thermal properties of the nanofibers were characterized by Scanning Electron Microscopy (SEM) and Thermal Gravimetric Analysis (TGA), respectively. Additionally, FT-IR analysis was performed to evaluate the functional groups of the samples.