FRACTAL GROWTH DURING EARLY-STAGE SPINODAL DECOMPOSITION IN A HYDROGEN-BONDED POLYMER BLEND

Small-angle neutron scattering has been used to study phase separation in a polymer blend made miscible by a dilute, random distribution of hydrogen bonds between the two components. In the one-phase region, sc attering below a well-defined wave vector q(c) remains weak as the cri tical point is approached. During the early stages of spinodal decompo sition, the formation of domains of a characteristic size R(t) greater -than-or-equal-to 1/q(c) is apparent as a peak in the time-dependent s tructure factor, which scales as q-2.40 independent of quench depth, r aising interesting questions about the morphology of early-stage spino dal decomposition in these mixtures.