Study of Morphological, Mechanical and Electrical properties of Electrospun Poly(lactic acid) Nanofibers incorporated with Multiwalled Carbon Nanotubes as a Function of Thermal Bonding.

Abstract

RAMASWAMY SANGEETHA. Study of Morphological, Mechanical and Electrical properties of Electrospun Poly (lactic acid) Nanofibers incorporated with Multiwalled Carbon Nanotubes as a Function of Thermal Bonding. (Under the direction of Dr. Russell E. Gorga and Dr Laura A. Clarke).

This work aims at enhancing the properties of electrospun poly (lactic) acid (PLA) nanofibers incorporated with various loading of multiwalled carbon nanotubes (MWNT) using the process of thermal bonding. Thermal bonding of the electrospun fibers improved the fiber-fiber bonds. Tensile strength of the nano-composites increased as a function of the bonding temperature. The modulus increased at lower bonding temperatures as the mat became more coherent and reduced at higher bonding temperatures as the stiffness of the mat decreased. A cold crystallization phenomenon was seen in the PLA nanofibers when bonded near the Tm, which lead to a sharp increase in tensile strength as well as modulus. The effect of thermal bonding on the electrical properties of the nanocomposites was also studied. It was found that the electrical conductance was the highest when the fibers were bonded close to their melting point. The percolative behavior of the nanocomposite mats bonded near the melting point was compared to the as-spun ones and it was found that improvement in the fiber-fiber bonds improved the connectivity of the mat and lowered the percolation threshold and raised the overall conductivity of the mat.