Kevin M. Kit and Sudhakar Jagannathan
Department of Material Science and Engineering
University of Tennessee, Knoxville

12th TANDEC International Nonwovens Conference, November 19-21, 2002, Knoxville, TN

Abstract

Electrospinning is a process by which fibers with diameters as small as 10 nanometers are produced when a polymer solution is accelerated from a capillary towards a grounded target by an electric field. When two different polymers are spun from a common solvent using this method, a nano-size fiber of the blend results whose final morphology is determined by the processing conditions and the properties of individual polymers. Hence this method is suitable to produce a homogenous phase for almost any polymer pair that is melt immiscible but soluble in a common solvent.

This electrospinning process has been used to spin nylon 6 and nylon 66 fibers and their blend from a solution of formic acid. The solution concentration of the polymer and the composition of the individual polymers are varied and its effect on the structure, morphology and properties are studied using the Scanning Electron Microscopy and Dynamic Mechanical Analyzer. The solution concentration is found to strongly affect the fiber size, with 5% solution of nylon 66 produced fibers as small as 15nm, which increased to size greater than 100nm as the concentration increases to 20%. The neat nylon 66 polymer produced fibers with structure more like non-woven fabric where as the nylon 6 polymer yielded a structure like a membrane. The blend with equal concentration of nylon 6 and nylon 66 polymers showed a combination of these morphologies.

The effects of composition, solution concentration, spinning voltage, target distance, polarity, and viscosity on the morphology and mechanical properties of the spun blends will be presented.