%0 Journal Article
%J Macromolecules
%D 1992
%T Small-angle neutron scattering from deuterated polystyrene in dioctyl phthalate solution under shear
%A Hammouda, B.
%A Nakatani, A. I.
%A Waldow, Dean
%A Han, C. C.
%P 2903-6
%V 25
%X Small-angle neutron scattering of high-mol.-wt. (1.95 x 106) polystyrene in dioctyl phthalate solns. was measured at low concn. (3% wt. fraction) under steady shear with rates ranging from the quiescent condition (0 s-1) to 1100 s-1 at room temp. (22.degree.). The scattered intensity increased dramatically beyond a characteristic shear rate (.gamma.c = 57 s-1) similar to the increase following a temp. drop from the one-phase region (ambient temp.) to the two-phase region in this upper crit. soln. temp. system. The RPA approach (the Zimm inverse scattering formula) was used along with a swollen radius of gyration in the Debye function to analyze the data and ext. a statistical segment length b and a polymer-solvent interaction parameter .CHI.ps. The segment length increased slightly, indicating a slight increase in chain vol. beyond .gamma.c, while the interaction parameter showed a dramatic increase up to the spinodal value .gamma.s = 280 s-1 where the RPA breaks down, therefore giving nonreliable values.