The Effect of Internal Additives on the Electrical Conductivity and Activation Energy of Nylon Fibers

The inclusion of internal antistatic agents in nylon 6 and nylon 6,6 fibers increases their electrical conductivity to a much greater degree than does the inclusion of "normal" nonantistatic internal additives. Commercial antistatic additives generally raise the conductivity of nylon fibers by a factor of 1000 compared with standard commercial yarns and by a factor of 10000 compared with yarns made from "pure" polymers. Incorporating approximately 5% poly (ethylene oxide) adducts in the polymer melt prior to extrusion of the fibers raises their electrical conductivity to a level comparable to that of commercial antistatic nylon fibers. The use of high amounts of additives up to 20% did not significantly increase the conductivity. The conductivity versus temperature behavior of fibers at a constant moisture regain of 4.1% is dramatically influenced by the addition of internal antistatic additives. In terms of activation energies, the additives reduced this characteristic of the yarn from approximately 43 kcal/mol to approximately 16-30 kcal/mol. This reduction in activation energy was produced with 5% by weight of the additive, and no additional reduction was achieved by mixing more than that amount of additive with the polymer prior to extrusion. There is some indication that the additives normally incorporated in fibers such as delustrants and stabilizers tend to reduce this "wet" activation energy of pure nylon by as much as 10 to 15%.