Electrospinning process optimization for Nylon 6,6/Epoxy hybrid nanofibers by using Taguchi method

Abstract

In this study, Taguchi method has been exploited to optimize the electrospinning process to produce hybrid nanofibers composed from Nylon 6, 6 (NY) and Epoxy (EP) polymers. Both polymers has been dissolved, with a sequence technique, in 80:20 mixture of Formic acid (FA)/Dichloromethane (DCM) solvent to form a homogenous electrospinnable (NY/EP/solvent) polymer solutions. Naylon 6, 6 was added to epoxy with weight ratio of 1, 2, 3, 4 and 5. NY/EP/solvent solutions were prepared and design of experiment was utilized to determine the optimal factors which affect the average electrospun hybrid nanofibers diameter of Nylon 6, 6/epoxy. The effect of two main factors (NY/EP ratios and Nylon 6, 6/solvent concentration) on the electrospun hybrid fiber diameter and its morphology was investigated. An extensive study for the effect of Berry’s number on the formation of hybrid fibers has been conducted too. Taguchi method and ANOVA results indicate that the Nylon 6, 6/solvent concentration is the most significant factor exhibiting best morphology and optimum diameter for the electrospun hybrid nanofibers. The minimum hybrid nanofiber diameter and its standard deviation was found to be 180 ± 35 nm corresponds to 8 wt% Nylon 6, 6/solvent and NY/EP ratio of 5:1. Infrared spectra and Nuclear magnetic resonance spectroscopy were used to confirm the coexistence of both epoxy and Nylon 6, 6 polymers in the electrospun hybrid nanofibers. Glass transition temperature of hybrid nanofibers was measured by differential scanning calorimeter. Incorporation of the epoxy in the fibers resulted in 5% increase in glass transition temperature indicating that the addition of epoxy has confined the mobility of the polymer chains. Also, an improvement in both tensile strength and modulus of elasticity of the electrospun NY/EP hybrid nanofibers has been notified and reported.