Block copolymers near the microphase separation transition 1. Preparation and physical characterization of a model system.
01 January 1984
A model set of 1,4-1,2 polybutadiene diblock copolymers have been prepared and molecularly characterized. Physical characterization by differential scanning calorimetry (DSC) and qualitative identification of the flow behavior (liquid versus solid-like) over a period of several days has established the critical degree of polymerization for this system as, N(c) =1.1 (+-0. 06)x10(3). Below the microphase separation transition the blends exhibit a single broad glass transition as measured by DSC, which has been attributed to local segment density fluctuations. This effect was found to be dependent on the degree of polymerization, as predicted from theory.