Abstract: The present invention includes a reactive elastomeric block co-oligomer; a copolymer containing a lactam, a co-catalyst/coupling agent, and the elastomeric block co-oligomer; and processes to make the block co-oligomer, and the copolymer.The reactive elastomeric block co-oligomer is the reaction product of a polycarboxylic acid, and a reactive moiety which can include a reactive polyether or a reactive polysulfide.The block co-oligomer of the present invention has been found to be useful to make a polymer containing lactam monomers, at least one coupling catalyst compound, and the block co-oligomer with the use of a catalyst.The present invention includes a process of forming the block co-oligomer of a polycarboyxlic acid and a reactive moiety. The reactive moiety can include a reactive polyether of a reactive polysulfide.The present invention further comprises a process of forming the block co-oligomer, and the process to form the lactam-block co-oligomer copolymer.