TY - CONF A1 - Pretsch, Thorsten ED - Kishi, Teruo ED - Böllinghaus, Thomas ED - Kitagawa, Masaki ED - Lexow, Jürgen T1 - Degradation, Functional Stability and Protection of a Shape Memory Polymer T2 - 1st World Materials Research Institutes Forum (WMRIF), Workshop for Young Materials Scientists CY - Tsukuba, Japan DA - 2008-07-22 KW - Formgedächtnispolymer KW - Poly(ester urethan) KW - Thermomechanische Eigenschaften KW - Hydrolyse PY - 2008 SN - 978-4-9900563-3-9 SP - XXX-1 - XXX11 AN - OPUS4-17819 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Ecker, Melanie A1 - Pretsch, Thorsten ED - Udomkichdecha, W. ED - Böllinghaus, Thomas ED - Manonukul, A. ED - Lexow, J. T1 - Freely configurable functionalization tool for switchable information carriers N2 - The selective compression of quick response (QR) and Data Matrix code carriers based on shape memory polymer (SMP) with a freely configurable steel ball type indenter and adjacent thermo-mechanical shape fixing gave notched, room temperature (23 °C) stable, temporary shapes with non-decipherable codes. The microscopic investigation of cryomicrotome sections unveiled indentation-related shape fixities of about 90 %. Independent of the selected two-dimensional code, the triggering of the SM effect resulted in sufficient shape recoveries to restore the code readability so that a maximum number of characters including 122 for a QR code (version 7) and 112 in case of a Data Matrix code (version 12) could be read with a scanning and decoding device. Due to the large number of difficult to copy shapes with on demand releasable information, SMPs may serve as viable information carriers for product and brand protection applications. KW - Shape memory polymer KW - QR code KW - Data matrix code KW - Freely configurable functionalization KW - Poly(ester urethane) KW - Programming KW - Thermo-responsiveness KW - Information carrier KW - Anti-counterfeiting KW - Brand protection KW - Smart label KW - Difficult-to-copy PY - 2014 UR - http://link.springer.com/chapter/10.1007/978-3-319-11340-1_3 SN - 978-3-319-11339-5 SN - 978-3-319-11340-1 DO - https://doi.org/10.1007/978-3-319-11340-1 SP - 25 EP - 35 PB - Springer AN - OPUS4-31576 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hättig, J. A1 - Bräuer, W. A1 - Pretsch, Thorsten T1 - Programmierbares TPU für den Produktschutz - Etiketten mit Gedächtnis N2 - Mit Formgedächtnispolymeren auf Basis von TPU sind Bauteile spritzgieß- oder extrudierbar, die sich vorübergehend durch eine gezielte thermomechanische Behandlung in einer anderen temporären Form fixieren und stabilisieren lassen. Damit können Informationen gespeichert, vorübergehend sicher verschlüsselt und als Quick Response (QR)-Codes mit schaltbarer Lesbarkeit auf TPU-Etiketten eingraviert werden. KW - Thermoplastisches Polyurethan (TPU) KW - Poly(ester uretahne) KW - Desmopan KW - Formgedächtnispolymer KW - Shape memory polymer KW - Smarte Etiketten KW - TPU Etiketten KW - Fälschungssicher KW - Smartphone KW - QR code KW - Färbeverfahren KW - Guest diffusion KW - TPU Folien KW - Technologieentwicklung PY - 2012 SN - 0032-1338 VL - 1 IS - 12 SP - 40 EP - 42 PB - Hüthig CY - Heidelberg AN - OPUS4-27776 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pretsch, Thorsten T1 - Review on the functional determinants and durability of shape memory polymers N2 - Shape memory polymers (SMP) belong to the class of stimuli-responsive materials and have generated significant research interest. Their capability to retain an imposed, temporary shape and to recover the initial, permanent shape upon exposure to an external stimulus depends on the "functional determinants", which in simplistic terms, can be divided into structural/morphological and processing/environmental factors. The primary aim of the first part of this review is to reflect the knowledge about these fundamental relationships. In a next step, recent advances in shape memory polymer composites are summarized. In contrast to earlier reviews, studies on the impairment of shape memory properties through various factors, such as aging, compression and hibernation, lubricants, UV light and thermo-mechanical cycling, are extensively reviewed. Apart from summarizing the state-of-the-art in SMP research, recent progress is commented. KW - Shape memory polymer KW - Active polymer KW - Shape memory polymer composite KW - Shape memory properties KW - Functionality KW - Degradation KW - Aging KW - Functional determinants KW - Thermo-mechanical testing KW - Durability PY - 2010 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-217390 UR - http://www.mdpi.com/2073-4360/2/3/120/pdf DO - https://doi.org/10.3390/polym2030120 SN - 2073-4360 VL - 2 IS - 3 SP - 120 EP - 158 PB - MDPI CY - Basel AN - OPUS4-21739 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mirtschin, Nikolaus A1 - Pretsch, Thorsten T1 - Designing temperature-memory effects in semicrystalline polyurethane N2 - Temperature-memory polymers are able to generate a substantial mechanical response when heated above the temperature, at which a preceding deformation was carried out. Here we show how to design the temperature-memory effect (TME) by thermomechanical treatment. As a model polymer, phase segregated poly(ester urethane) (PEU) containing crystallizable segments of poly(1,4-butylene adipate) (PBA) was used. For programming, strain elongation was applied at temperatures within the PBA melting transition area, before temperature holding, unloading and cooling were carried out. Upon heating under stress-free or constant strain recovery conditions, precisely set temperature-memory onsets could be witnessed. Most importantly, strain fixities and recoverabilities the same as maximum recovery stresses turned out to be controllable by strain rate and temperature holding time after deformation, while transition temperatures remained largely unaffected. The tailoring of thermoresponsiveness was structurally enabled by different PBA crystallinities in the programmed state as verified by wide-angle X-ray scattering (WAXS). The reported studies intend to design TMEs in semicrystalline polyurethanes according to user-defined needs to make this technology broadly applicable. KW - Poly(ester urethane) KW - Shape memory polymer KW - Temperature-memory effect KW - Thermo-responsiveness KW - Temperature-memory polymer KW - Programming KW - Thermomechanical properties PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-332856 DO - https://doi.org/10.1039/c5ra05492c SN - 2046-2069 VL - 5 IS - 57 SP - 46307 EP - 46315 PB - RSC Publishing CY - London AN - OPUS4-33285 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ecker, Melanie A1 - Pretsch, Thorsten T1 - Novel design approaches for multifunctional information carriers N2 - Two design approaches for multifunctional information carriers are introduced. In the first one, quick response (QR) code carriers, which were composed of poly(ester urethane) (PEU) and microencapsulated thermochromic pigments (T-PIGs), differing in color and color switching temperature (CST), were prepared. The obtained material systems exhibited machine-readable QR codes at 23 °C and a two-stage decolorization when heated, culminating in unreadable QR codes at temperatures above the highest CST of the employed T-PIGs. In the second scenario, information carriers were sealed with a dark, thermochromic PEU layer. As a result, the QR codes were hidden at 23 °C and became readable upon heating due to color fading. Beyond the characterization of the employed components, preparation methods, functionality analyses and durability investigations are reported. When heated after thermo-mechanical programming, pronounced shape memory properties could be verified. The thermo-responsiveness of such multifunctional material systems may qualify them for usage in anti-counterfeiting applications. KW - Poly(ester urethane) KW - Shape memory polymer KW - Thermo-responsiveness KW - Information carrier KW - QR code carrier KW - Thermochromic properties KW - Microencapsulated thermochromic pigments KW - Anti-counterfeiting KW - Smart label KW - Difficult-to-copy KW - Durability KW - Multifuncitonal material systems PY - 2014 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-315176 DO - https://doi.org/10.1039/c4ra08977d SN - 2046-2069 VL - 4 IS - 87 SP - 46680 EP - 46688 PB - RSC Publishing CY - London AN - OPUS4-31517 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pretsch, Thorsten A1 - Ecker, Melanie A1 - Schildhauer, Markus A1 - Maskos, Michael T1 - Switchable information carriers based on shape memory polymer N2 - Herein we demonstrate the realization of a new technological concept, which enables the use of shape memory polymers (SMPs) as switchable information carriers. At first, we applied a surface-specific dyeing process based on 'guest-diffusion' on two sophisticated polymeric host materials, including a thermoplastic poly(ester urethane) SMP and a thermoset epoxy-based SMP. Upon drying, self-assembly of the dye molecules inside the polymer surfaces occurred, resulting in homogeneous color penetration depths of about 100 µm. Subsequently, the colored surfaces were patterned with quick response (QR) codes. For this purpose, laser ablation was used. The resulting cavity depth was exceeding the color penetration depth. This assured sufficient surface contrast and rendered the QR codes machine-readable. In a progressive approach, two thermo-mechanical functionalization protocols were designed in accordance with the thermal properties of the polymers. As a result of programming, the tag prototypes were converted into stable, temporary shapes with non-decodable QR code information. When thermally triggering the shape memory effect on the functionalized tags, we verified the mostly complete recovery of the polymer surface and the associated restoration into the almost original shape. As such, the QR code could again precisely be read out. We anticipate that tagging products with these information carriers is helpful for the purpose of secure one-time identification. KW - Shape memory polymer KW - Epoxy-based polymer KW - Poly(ester urethane) KW - Thermo-responsive polymer KW - Laser ablation KW - Laser marking KW - QR code KW - Functionalized tags KW - Tag technology KW - Smart tagging KW - Switchable information carrier KW - Authentification KW - Identification KW - Surface-specific dyeing KW - Guest diffusion PY - 2012 DO - https://doi.org/10.1039/c2jm16204k SN - 0959-9428 SN - 1364-5501 VL - 22 IS - 16 SP - 7757 EP - 7766 PB - Royal Society of Chemistry CY - Cambridge AN - OPUS4-25737 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bothe, Martin A1 - Emmerling, Franziska A1 - Pretsch, Thorsten T1 - Poly(ester urethane) with varying polyester chain length: Polymorphism and shape-memory behavior N2 - The swelling, viscoelastic, and mechanical behavior of phase-segregated poly(ester urethane) (PEU) block copolymers, composed of 4,4'-methylenediphenyl diisocyanate, 1,4-butanediol as a chain extender, and crystallizable poly(1,4-butylene adipate) (PBA) with molecular weights between 1330 and 4120 g mol-1, are investigated. Wide-angle X-ray scattering (WAXS) is employed to study the overall PEU crystallinity, which increases from 8.6 to 13.6% at higher PBA contents. The existence of two crystalline, polymorphic PBA phases, a thermodynamically stable α phase and a metastable β phase, is confirmed by further WAXS measurements. Calorimetric and thermomechanical investigations give evidence for controllable PBA polymorphic behavior. The crystallization conditions, like the cooling rate, affect the emerging polymorphic mixture, whereas the storage conditions either promote or inhibit the polymorphic (β to α) transition. The introduced concepts represent a new approach for gaining control over programmable thermo­responsiveness, which may be transferable to other shape-memory polymers with polymorphic switching segments. KW - Shape-memory polymers KW - Stimuli-sensitive polymers KW - Poly(ester urethane) KW - Polymorphism PY - 2013 DO - https://doi.org/10.1002/macp.201300464 SN - 1022-1352 SN - 1521-3935 VL - 214 IS - 23 SP - 2683 EP - 2693 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-29892 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -