Abstract: Five 4-arm-and four 7-arm-star shaped polystyrene samples different in molecular weight have been prepared and examined by GPC combined viscosimetry. A theoretical treatment method is proposed to obtain the factor g'θ(=[η]b,θ/[η]l.θ.)from viscosity in good solvent. The difference between the factor g(=[η]b/[η]l) and g'θ,as well as the ∈-value in the relationship between g'θ, and gθ( =S²_b,θ/S²_i,θ), (g'θ=g_θ^ε) have been discussed.The results verified that the ∈-value not only depends on the type of branching, but also depends on the degree of branching, ∈=1.487 and 1.14 for 4-arm and 7-arm star polystyrene, respectively. The difference between g' and g'θ is smaller for 4-arm star polystyrene, but is larger for 7-arm star polystyrene.

Key words: star-shaped branched polystyrene, GPC-viscometry, solution property