Synthesis, hydrogenation, and rheology of 1,2-polybutadiene star polymers

A series of symmetric star polymer melts were synthesized with arm molecular weights varying between 10 000 and 80 000 g mol(-1). Each sample had a three-arm architecture and was predominately made up of 1,2 enchained polybutadiene repeat units, A portion of each sample was hydrogenated to give the corresponding poly(l-butene) material. Mechanical analysis was carried out on both the parents and saturated analogues. Results obtained from these rheological investigations were compared to theoretical predictions calculated using the Milner-McLeish theory and found to agree well over the frequency range employed, for both "parent" and "daughter" products.