Method for the preparation of polymers of lactams having an enhanced electric conductivity

The invention relates to a method for the preparation of polyamides with enhanced electric conductivity (specific resistance below 109 OMEGA .cm) by the anionic polymerization of lactams with 7 to 13 atoms in the ring using the usual basic polymerization initiators and accelerating activators. The polymerization is carried out in the presence of 2-20 wt. parts of plasticizers, e.g. N,N-dialkoxy or N,N-dialkylacrylamides or methacrylamides or their polymers, polyethyleneoxide, polyamides or lactams of higher concentration of amide groups than has the principal lactam, and 1-50 wt. parts of a very finely ground graphite and/or conductive black per 100 wt. parts of anhydrous principal lactam or mixture of lactams.The polymerization is performed in a mold to give directly the required article or in continuous reactors to various profiles or to form granulates. The semiconductive polyamide, which is the product of this invention, is suitable, for instance, for use as machine parts operating under conditions where the formation of electrostatic charges should be eliminated (e.g. in mines, chemical plants, etc.) or for articles where the conductivity is usefully employed (e.g. low temperature heating elements).