The present invention is directed to a process for preparing polymers which may be coupled (reacted) at temperatures above about 200.degree. C., the process comprising first reacting monomer(s) selected from conjugated dienes and monoalkenyl arenes with an organomonolithium initiator and then reacting the resulting polymeric arms (P-Li) with certain arylcyclobutene monomers. These arylcyclobutene monomers have the formula ##STR1## where X is an alkylene or arylene group, Z is an arylcyclobutene group, R is selected from the group consisting of aryl groups, alkyl groups, ##STR2## and H, and R.sup.1 is an aryl group or alkyl group.