Modified molecular weight of polylactams

A molecular weight modified nylon, comprising:

• anionically polymerized lactam monomers having the formula ##EQU3## wherein n is 5 to 12, and containing from about 0.001 to about 30 mole percent based upon the lactam of a hydrocarbon compound selected from the class consisting of fluorene, 9-phenylpropene, acetylene, phenylacetylene, indene, cyclopentadiene and 1,3,3-triphenylpropene.

A molecular weight modified nylon, comprising;

• anionically polymerized lactam monomers having the formula ##EQU4## wherein n is from 2 to 15, from about 0.01 to about 20 mole percent of an anionic initiator based on said lactam monomers, from 0.1 to about 20 equivalents based upon said initiator of a hydrocarbon compound lacking any active hydrogen attached to an atom selected from the group consisting of nitrogen, oxygen and sulfur, and having a Mc-Ewen-Streitwieser-Applequist-Dessy scale pk.sub.a of from about 15 to about 29, so that the modified molecular weight is similar to the expected calculated molecular weight.

A method for the preparation of nylons having modified molecular weights which comprises anionically polymerized lactams having the formula ##EQU5## wherein n is from 2 to 15, and carrying said polymerization out in the presence of from 0.001 to about 30 mole percent based upon the lactam of a hydrocarbon compound having a McEwen-Streitwieser-Applequist-Dessy scale pK.sub.a of from about 15 to about 29.

A method for the preparation of nylons having modified molecular weights which comprises an anionically polymerizing lactams having the formula ##EQU6## where n is from 5 to 12, and containing from 0.001 to about 30 mole percent of the hydrocarbon compound selected from the class consisting of fluorene, 9-phenylfluorene, acetylene, phenylacetylene, indene, cyclopentadiene and 1,3,3-triphenylpropene.

A method for the preparation of nylons having modified molecular weights which comprises anionically polymerized lactams having the formula ##EQU7## wherein n is from 2 to 15, adding from about 0.01 to about 20 mole percent of anionic initiators based on said lactam monomers, adding from about 0.1 to about 20 equivalents based upon said initiator of a hydrocarbon compound lacking any active hydrogen attached to an atom selected from the group of nitrogen, oxygen and sulfur and having a McEwen-Streitwieser-Applequist-Dessy scale pK.sub.a of from about 15 to about 29, so that the modified molecular weight is similar to the expected calculated molecular weight.