Contact electrification of polyamides

Abstract

Charge transfer to nylon 6.6 and other polyamides is a characteristic of the material, and to a large extent independent of source and fabrication history. A variety of polyamides with a range of amide group concentrations all charge strongly positive to much the same extent, but polyolefins (equivalent to polyamides with zero concentration of amide groups) charge very much more weakly. We conclude that the positive charge transfer is attributable to the amide group but the charge transfer saturates at an amide concentration well below that of all the polyamide samples studied. For molecular weights typical of commercial nylon 6.6 the contact charge density is much closer to the concentration of amine end-groups than to the concentration of amide linkages; however, our experiments show that the charge transfer is independent of the concentration of amine ends over a wide range.