Structural, mechanical, and tribological properties of electrospun poly(hexamethylene adipamide) fiber mats

Abstract

The mechanical and tribological properties of electrospun fiber mats are of paramount importance to their utility in a large number of applications. In this work, mats of electrospun fibers of poly(hexamethylene adipamide) (PA 6,6) with average fiber diameter of 238±22nm are characterized for their crystal structure as well as their mechanical and tribological properties. Post-spin thermal annealing was used to modify the fiber morphology and crystallinity within the fibers. Morphological changes, in-plane tensile response, friction coefficient and wear rate were characterized as functions of the annealing temperature. The mechanical and tribological properties of the thermally annealed PA 6,6 fiber mats exhibited significant improvements through the Brill transition temperature, comparable to the improvements observed for amorphous polyamide electrospun mats annealed near the glass transition temperature. The effective wear rate of the electrospun fiber mats is well-described by a previously proposed modification of the Ratner-Lancaster relationship that relates wear to the yield behavior of these nonwoven mats.