(39a) Phase Behavior of Multblock Terpolymers
Block copolymers are well recognized as ideal compounds for generating nanoscale structures with well defined morphologies that are arranged with rotational and translational order. Most research attention and commercial applications have focused on AB diblock and ABA triblock copolymers. Over the last two decades a host of experimental and theoretical studies dealing with ABC triblock terpolymers have revealed over thirty unique ordered morphologies, with many more likely to be discovered. We have synthesized two types of architecturally asymmetric ABAC tetrablock terpolymers, SISO and CECD, from poly(isoprene) (I), poly(styrene) (S), poly(ethylene oxide) (O), poly(cyclohexylethylene) (C), poly(ethylene (E) and poly(dimethylsiloxane) (D). Phase behavior was characterized for various compositions using small-angle X-ray scattering (SAXS), transmission electron microscopy (TEM), dynamic mechanical spectroscopy (DMS) and differential scanning calorimetry. This presentation will describe how the addition of a symmetry breaking fourth block to linear ABA triblocks impacts the structure and properties of these materials.