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Elastic bicomponent networks with shape memory effect were obtained via cross-linking reactions of unsaturated polyester with methacrylates. Unlike conventional shape memory polymers, the new material is transparent, rubbery, and can be tailored to various transition temperatures by macromolecular engineering. Various unsaturated copolymers of α-methylene-γ-butyrolactone and e-caprolactone were synthesized by ring-opening mechanism. Depending on the composition of the unsaturated polyester materials, their mechanical properties and glass transition temperature were varied.

We report on the synthesis of poly(l-lysine-b-caprolactone) block copolymers via an original and elegant approach whereby Z-l-lysine is first polymerized in the presence of allylamine and the resulting amino-terminated poly(Z-l-lysine) is then used in situ as macroinitiator for the polymerization of e-caprolactone in the presence of tin(II) octanoate as catalyst. A range of poly(ester-b-peptide)s were obtained by varying the ratio of polypeptide to polycaprolactone units. After removal of the Z group of l-lysine units, the copolymers were soluble in water and their solution behavior was examined. They spontaneously form micelle-like objects in solution with sizes around 10 and 70 nm depending on the block lengths of the hydrophilic and hydrophobic sequences. The smaller size particles would adopt a core−shell morphology while the larger particles would be more in line with a vesicle morphology.

3,5,5‘-Trimethylcaprolactone and 3,3‘,5-trimethylcaprolactone are characterized with various spectroscopic methods. Their ability of ring-opening is correlated with semiempirical calculations and is compared to unsubstituted lactones of different ring sizes. The results of the computations are verified by measurements of reaction kinetics of the polymerizations.

Block copolymers containing metal centers and related segmented architectures are attracting attention as a class of materials with properties and functions that complement those of their all-organic analogues. These materials phase-separate into nanoscopic, metal-rich domains either in bulk or in thin films and form core–shell nanoparticles in selective solvents. Moreover, the linkages binding the metal centers can be varied from covalent bonds that lead to “static” bonding through to noncovalent, kinetically labile, or “dynamic” interactions, which affords remarkable flexibility in terms of materials design. In this Perspective we provide an overview of recent progress and future challenges in terms of applications in nanopatterning and sensing, and as stimuli-responsive and self-healing materials.