Viscoelastic behavior of C-60-end-capped linear polybutadiene and C60-end-capped poly(butadiene-co-styrene) with molecular weight (M-n) ranging from 30 to 130 kg/mol and with polydispersity index (M-w/M-n) ranging from 1.02 to 1.08 was investigated. These polymers were synthesized through anionic polymerization of butadiene and styrene in hexane, in which the living ends were capped with the C-60 via an alcoholate bridging. Rheological measurements showed that the polymer dynamics in the terminal zone were profoundly affected by the presence of fullerene, while the dynamics in the entanglement-plateau and at the terminal relaxation were nearly unaffected. (c) 2006 Elsevier Ltd. All rights reserved.