ABSTRACTDeuterated polybutadiene and protonated polybutadiene (PBD/PBH) blends with various microstructures have been studied by the small-angle neutron scattering experiments. Correlation length, ξ, zero-wavenumber structure factor, S(q=o), and interaction parameter, Xblend have been obtained. All PBD/PBH blends exhibit UCST behavior. With the use of random copolymer theory, the interaction parameter, Xblend, has been successfully separated into X1, X2 and X3 which are interaction parameters between the same isotope labeled 1,2-unit and 1,4-unit, opposite isotope labeled 1,2-unit and 1,4- unit, and opposite isotope labeled 1,2-unit with 1,2-unit or 1,4-unit with 1,4-unit, respectively.
