Thermal and Bulk Properties of Triblock Terpolymers and Modified Derivatives towards Novel Polymer Brushes.

We report the synthesis of three (3) linear triblock terpolymers, two (2) of the ABC type and one (1) of the BAC type, where A, B and C correspond to three chemically incompatible blocks such as polystyrene (PS), poly(butadiene) of exclusively (~100% vinyl-type) -1,2 microstructure (PB) and poly(dimethylsiloxane) (PDMS) respectively. Living anionic polymerization enabled the synthesis of narrowly dispersed terpolymers with low average molecular weights and different composition ratios, as verified by multiple molecular characterization techniques. To evaluate their self-assembly behavior, transmission electron microscopy and small-angle X-ray scattering experiments were conducted, indicating the effect of asymmetric compositions and interactions as well as inversed segment sequence on the adopted morphologies.

Molecular and Structure-Properties Comparison of an Anionically Synthesized Diblock Copolymer of the PS--PI Sequence and Its Hydrogenated or Sulfonated Derivatives.

An approach to obtaining various nanostructures utilizing a well-studied polystyrene--poly(isoprene) or PS--PI diblock copolymer system through chemical modification reactions is reported. The complete hydrogenation and partial sulfonation to the susceptible carbon double bonds of the PI segment led to the preparation of [polystyrene--poly(ethylene--propylene)] as well as [polystyrene--poly(sulfonated isoprene--isoprene)], respectively. The hydrogenation of the polyisoprene block results in enhanced segmental immiscibility, whereas the relative sulfonation induces an amphiphilic character in the final modified material.

Self-Assembly of Low-Molecular-Weight Asymmetric Linear Triblock Terpolymers: How Low Can We Go?

The synthesis of two (2) novel triblock terpolymers of the ABC type and one (1) of the BAC type, where A, B and C are chemically different segments, such as polystyrene (PS), poly(butadiene) (PB) and poly(dimethylsiloxane) (PDMS), is reported; moreover, their corresponding molecular and bulk characterizations were performed. Very low dimensions are evident from the characterization in bulk from transmission electron microscopy studies, verified by small-angle X-ray data, since sub-16 nm domains are evident in all three cases. The self-assembly results justify the assumptions that the high Flory-Huggins parameter, , even in low molecular weights, leads to significantly well-ordered structures, despite the complexity of the systems studied.