Small-angle neutron scattering studies on phase behavior of block copolymers

Miscibility and phase behavior of a deuterated polybutadiene-block-polyisop rene diblock copolymer (DPB-HPI) were investigated by means of small-angle neutron scattering as a function of temperature and pressure. This copolyme r exhibited lower critical ordering transition-type phase behavior. In a wi de temperature range below the order-disorder transition, the inverse scatt ered intensity maximum of the first-order peak linearly increases with the inverse absolute temperature, in agreement with the predictions of the mean -field theory. We found anomalously large pressure dependence of the spinod al temperature estimated from the temperature dependence of the susceptibil ity. (C) 1999 Elsevier Science Ltd. All rights reserved.