TY - JOUR A1 - Julich-Gruner, Konstanze K. A1 - Löwenberg, Candy A1 - Neffe, Axel T. A1 - Behl, Marc A1 - Lendlein, Andreas T1 - Recent trends in the chemistry of shape-memory polymers JF - Macromolecular chemistry and physics N2 - Shape-memory polymers (SMPs) are stimuli-sensitive materials capable of performing complex movements on demand, which makes them interesting candidates for various applications, for example, in biomedicine or aerospace. This trend article highlights current approaches in the chemistry of SMPs, such as tailored segment chemistry to integrate additional functions and novel synthetic routes toward permanent and temporary netpoints. Multiphase polymer networks and multimaterial systems illustrate that SMPs can be constructed as a modular system of different building blocks and netpoints. Future developments are aiming at multifunctional and multistimuli-sensitive SMPs. KW - multifunctional polymers KW - networks KW - shape-memory polymers KW - stimuli-sensitive polymers KW - triple-shape effect Y1 - 2013 U6 - https://doi.org/10.1002/macp.201200607 SN - 1022-1352 VL - 214 IS - 5 SP - 527 EP - 536 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Sauter, Tilman A1 - Kratz, Karl A1 - Lendlein, Andreas T1 - Pore-size distribution controls shape-memory properties on the macro- and microscale of polymeric foams JF - Macromolecular chemistry and physics N2 - Open porous foams with identical foam density but different pore-size distributions (bimodal or monomodal) are prepared from a shape-memory polyetherurethane (PEU) by thermally induced phase separation. The shape-memory effect of the two PEU foams is explored by cyclic thermomechanical compression tests and microstructural analysis. The obtained results reveal that the PEU foam with a bimodal pore-size distribution exhibits an increased shape-recovery under stress-free conditions, both on the macro- (foam level) as well as the microscale (pore level). While bimodal pore-size distributions induce microscale bending during compression, buckling occurs in foams with monomodal pore-size distributions, leading to both a reduced and delayed shape recovery. KW - microstructure KW - morphology KW - polymer foams KW - pore-size distribution KW - shape-memory polymers Y1 - 2013 U6 - https://doi.org/10.1002/macp.201300062 SN - 1022-1352 VL - 214 IS - 11 SP - 1184 EP - 1188 PB - Wiley-VCH CY - Weinheim ER -