PLA belongs to the well-known shape-memory polymers which can be used, e.g., to completely modify the geometry of open-pore 3D printed PLA objects and afterwards restore the original shape by warming up the object.
Recently, poly(ethylene glycol) (PEG) was also found to show shape-memory properties. Using PEG with different low molecular weights, the materials were chain-end functionalized with isocyanate ethyl methacrylate and UV-photo-cured, resulting in nearly complete cross-linking. In 3-point bending tests, nearly 100 % strain fixity rates were found.
The activation temperature stronlgy depended on the molecular weights of the used PEGs. This finding allows for tailoring the temperature range for the thermal activation of the shape-memory effects.
F. S. Senatov, K. V. Niaza, M. Y. Zadorozhnyy, A. V. Maksimkin, S. D. Kaloshkin, Y. Z. Estrin
Mechanical properties and shape memory effect of 3D printed PLA-based porous scaffolds
Journal of the Mechanical Behavior of Biomedical Materials 57, 139-148 (2016)
O. Boumezgane and M. Messori
Poly(ethylene glycol)-based shape-memory polymers
International Journal of Polymer Analysis and Characterization 22, 463-471 (2017)