@article{MazurekBudzyńskaBehlNeumannetal.2022,
  author    = {Mazurek-Budzyńska, Magdalena and Behl, Marc and Neumann, Richard and Lendlein, Andreas},
  title     = {4D-actuators by 3D-printing combined with water-based curing},
  series = {Materials today. Communications},
  volume    = {30},
  journal   = {Materials today. Communications},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {2352-4928},
  doi       = {10.1016/j.mtcomm.2021.102966},
  pages     = {7},
  year      = {2022},
  abstract  = {The shape and the actuation capability of state of the art robotic devices typically relies on multimaterial systems from a combination of geometry determining materials and actuation components. Here, we present multifunctional 4D-actuators processable by 3D-printing, in which the actuator functionality is integrated into the shaped body. The materials are based on crosslinked poly(carbonate-urea-urethane) networks (PCUU), synthesized in an integrated process, applying reactive extrusion and subsequent water-based curing. Actuation capability could be added to the PCUU, prepared from aliphatic oligocarbonate diol, isophorone diisocyanate (IPDI) and water, in a thermomechanical programming process. When programmed with a strain of epsilon(prog) = 1400\% the PCUU networks exhibited actuation apparent by reversible elongation epsilon'(rev) of up to 22\%. In a gripper a reversible bending epsilon'(rev)((be)(nd)()) in the range of 37-60\% was achieved when the actuation temperature (T-high) was varied between 45 degrees C and 49 degrees C. The integration of actuation and shape formation could be impressively demonstrated in two PCUU-based reversible fastening systems, which were able to hold weights of up to 1.1 kg. In this way, the multifunctional materials are interesting candidate materials for robotic applications where a freedom in shape design and actuation is required as well as for sustainable fastening systems.},
  language  = {en}
}
@article{MazurekBudzyńskaBehlRazzaqetal.2019,
  author    = {Mazurek-Budzyńska, Magdalena and Behl, Marc and Razzaq, Muhammad Yasar and N{\"o}chel, Ulrich and Rokicki, Gabriel and Lendlein, Andreas},
  title     = {Hydrolytic stability of aliphatic poly(carbonate-urea-urethane)s: Influence of hydrocarbon chain length in soft segment},
  series = {Polymer Degradation and Stability},
  volume    = {161},
  journal   = {Polymer Degradation and Stability},
  publisher = {Elsevier},
  address   = {Oxford},
  issn      = {0141-3910},
  pages     = {283 -- 297},
  year      = {2019},
  abstract  = {Poly(carbonate-urethane)s (PCUs) exhibit improved resistance to hydrolytic degradation and in vivo stress cracking compared to poly(ester-urethane)s and their degradation leads to lower inflammation of the surrounding tissues. Therefore, PCUs are promising implant materials and are considered for devices such as artificial heart or spine implants. In this work, the hydrolytic stability of different poly(carbonate-urethane-urea)s (PCUUs) was studied under variation of the length of hydrocarbon chain (6, 9, 10, and 12 methylene units) between the carbonate linkages in the precursors. PCUUs were synthesized from isophorone diisocyanate and oligo(alkylene carbonate) diols using the moisture-cure method. The changes of sample weight, thermal and mechanical properties, morphology, as well as the degradation products after immersion in a buffer solution (PBS, pH = 7.4) for up to 10 weeks at 37 degrees C were monitored and analyzed. In addition, mechanical properties after 20 weeks (in PBS, 37 degrees C) were investigated. The gel content was determined based on swelling experiments in chloroform. Based on the DSC analysis, slight increases of melting transitions of PCUUs were observed, which were attributed to structure reorganization related to annealing at 37 degrees C rather than to the degradation of the PCUU. Tensile strength after 20 weeks of all investigated samples remained in the range of 29-39 MPa, whereas the elongation at break e(m) decreased only slightly and remained in the range between 670 and 800\%. Based on the characterization of degradation products after up to 10 weeks of immersion it was assessed that oligomers are mainly consisting of hard segments containing urea linkages, which could be assigned to hindered-urea dissociation mechanism. The investigations confirmed good resistance of PCUUs to hydrolysis. Only minor changes in the crystallinity, as well as thermal and mechanical properties were observed and depended on hydrocarbon chain length in soft segment of PCUUs. (C) 2019 Published by Elsevier Ltd.},
  language  = {en}
}
@article{PengBehlZhangetal.2017,
  author    = {Peng, Xingzhou and Behl, Marc and Zhang, Pengfei and Mazurek-Budzyńska, Magdalena and Feng, Yakai and Lendlein, Andreas},
  title     = {Synthesis and characterization of multiblock poly(ester-amide-urethane)s},
  series = {MRS advances : a journal of the Materials Research Society (MRS)},
  volume    = {2},
  journal   = {MRS advances : a journal of the Materials Research Society (MRS)},
  publisher = {Cambridge University Press},
  address   = {Cambridge},
  issn      = {2059-8521},
  doi       = {10.1557/adv.2017.486},
  pages     = {2551 -- 2559},
  year      = {2017},
  abstract  = {In this study, a multiblock copolymer containing oligo(3-methyl-morpholine-2, 5-dione) (oMMD) and oligo(3-sec-butyl-morpholine-2, 5-dione) (oBMD) building blocks obtained by ring-opening polymerization (ROP) of the corresponding monomers, was synthesized in a polyaddition reaction using an aliphatic diisocyanate. The multiblock copolymer (pBMD-MMD) provided a molecular weight of 40, 000 g·mol-1, determined by gel permeation chromatography (GPC). Incorporation of both oligodepsipeptide segments in multiblock copolymers was confirmed by 1H NMR and Matrix Assisted Laser Desorption/Ionization Time Of Flight Mass Spectroscopy (MALDI-TOF MS) analysis. pBMD-MMD showed two separated glass transition temperatures (61 °C and 74 °C) indicating a microphase separation. Furthermore, a broad glass transition was observed by DMTA, which can be attributed to strong physical interaction i.e. by H-bonds formed between amide, ester, and urethane groups of the investigated copolymers. The obtained multiblock copolymer is supposed to own the capability to exhibit strong physical interactions.},
  language  = {en}
}