TY - JOUR A1 - Hättig, J. A1 - Bräuer, W. A1 - Pretsch, Thorsten T1 - Ein Kunststoff, der sich erinnert - Einsatzchancen von thermoplastischem Polyurethan mit Formgedächtnis N2 - Ein neu entwickeltes thermoplastisches Polyurethan (TPU) ist alles andere als „vergesslich". Formteile aus dem Material lassen sich in einer temporären Form fixieren und wieder nahezu in ihre ursprüngliche Gestalt zurückverwandeln. Dieser Formgedächtniseffekt hat gute Anwendungschancen - vom Marken- und Produktschutz über den Maschinen- und Automobilbau, bis hin zur Freizeit- und Spielzeugindustrie. KW - Thermoplastisches Polyurethan (TPU) KW - Desmopan DP 2795A SMP KW - Formgdächtnispolymer KW - Shape memory polymer KW - Smarte Etiketten KW - Schaltbare Etiketten KW - Produkt und Markenschutz KW - Smartphone KW - QR code KW - Färbeverfahren KW - Guest diffusion KW - TPU Folie KW - Selbst-aufrichtende Treibhäuser KW - Folientunnel PY - 2013 SN - 0344-4570 VL - 4 SP - 92 EP - 94 PB - Vereinigte Fachverl. CY - Mainz AN - OPUS4-28081 LA - deu 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 - CONF A1 - Ecker, Melanie A1 - Pretsch, Thorsten T1 - Durability of QR code carriers based on shape memory polymer N2 - The surface of a shape memory poly(ester urethane) (PEU) was either black- or blue-colored to obtain switchable quick response (QR) codes after laser engraving and thermomechanical functionalization (programming). The investigation of dye and functional stability against UVA and hydrolytic aging (at 23 and 60 °C) gave that contrast decline due to dye decolorization (in case of UVA aging) or distinct dye diffusion (in case of hydrolytic aging) finally inhibited the QR code readability. By contrast, PEU as marked base material could be adequately fixed and recovered even when the Michelson contrast in the QR code region was falling in course of aging below a crucial value of 0.1, whereupon the QR code was no longer readable. Hence, we concluded that under the given experimental conditions the decisive parameter for tag applicability was the surface contrast. T2 - SMASIS2012 - ASME 2012 Conference on smart materials, adaptive structures and intelligent systems CY - Stone Mountain, Georgia, USA DA - 2012-09-19 KW - Shape memory polymer KW - Durability KW - QR code KW - Poly(ester urethane) KW - Product and brand protection applications KW - Counterfeit-proof labels KW - Tags KW - QR code carriers KW - Switchable information carriers KW - Functionalization KW - Surface-specific dyeing PY - 2012 IS - SMASIS2012-8038 SP - 1 EP - 8 PB - ASME AN - OPUS4-27884 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mirtschin, Nikolaus A1 - Pretsch, Thorsten T1 - Miniturization of QR code carriers based on shape memory polymer N2 - Here we present a suitable tag prototype with phasesegregated poly(ester urethane) (PEU) as base material for effectively switching a quick response (QR) code in its surface from non-readable to readable. In comparison with recently introduced tags (different geometry) we minimized the thickness from plaque (2 mm) to foil size (0.5 mm) and reduced the lateral QR code length from 15 to 5 mm. Subsequent to surface-dyeing by means of guest diffusion, the QR code was laser-engraved. The implementation of thermo-mechanical functionalization via tensile deformation and cooling resulted in the formation of stable shapes, which exceeded the barrier of QR code readability at an elongation of 20%. Once functionalized, tags were switched on demand by heating. As such the recovery of the PEU was accomplished and the QR code could again be read out. QR code carriers based on shape memory polymer can be used in product and brand protection applications. T2 - SMASIS2012 - ASME 2012 Conference on smart materials, adaptive structures and intelligent systems CY - Stone Mountain, Georgia, USA DA - 2012-09-19 KW - Shape memory polymer KW - QR code KW - Poly(ester urethane) KW - Product and brand protection applications KW - Counterfeit-proof labels KW - Tags KW - Switchable information carriers KW - Functionalization KW - Miniaturization KW - Surface-specific dyeing KW - Victoria Blue B PY - 2012 N1 - Geburtsname von Mirtschin, Nikolaus: Fritzsche, N. - Birth name of Mirtschin, Nikolaus: Fritzsche, N. IS - SMASIS2012-8036 SP - 1 EP - 8 PB - ASME AN - OPUS4-27886 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ecker, Melanie A1 - Pretsch, Thorsten 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. T2 - 3rd WMRIF Workshop for young materials scientists CY - Pathumthani, Thailand DA - 2012-08-28 KW - Shape memory polymer KW - QR code KW - Data matrix code KW - Poly(ester urethane) KW - Product and brand protection applications KW - Tags KW - Switchable information carriers KW - Freely configurable functionalization KW - Selective deformation KW - Steel ball type indenter KW - Spherical indentation KW - Cryomicrotome sections KW - Surface-specific dyeing PY - 2012 SP - 1 EP - 10(?) AN - OPUS4-27887 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bothe, Martin A1 - Mya, K.Y. A1 - Lin, E.M.J. A1 - Yeo, C. C. A1 - Lu, X. A1 - He, C. A1 - Pretsch, Thorsten T1 - Triple-shape properties of star-shaped POSS-polycaprolactone polyurethane networks N2 - Here, we present an investigation of the triple-shape properties of star-shaped polyhedral oligomeric silsesquioxane-poly(ε-caprolactone) polyurethanes (SPOSS-PUs), which have three-dimensional network structures. In a typical 'triple-shape functionalization process', mostly consisting of two tensile deformations at different temperatures, chain immobilization of the polymer network component poly(ε-caprolactone) (PCL) was successfully realized first through crystallization and then through vitrification. Subsequently, large parts of the respective strains were released under stress-free recovery conditions. The two-fold fixed ('programmed') specimens responded to heating with two independent length contractions (switching steps); the first shape change was associated with PCL devitrification and the second one with the melting of hitherto crystalline PCL. It was revealed that the triple-shape properties of SPOSS-PU networks considerably depend on PCL network chain length. When applying exactly the same 'triple-shape creation procedure', larger strain releases were detected in the first transition for polymers with a higher PCL network chain length, whereas the second transition was more accentuated for SPOSS-PU networks with a shorter PCL chain length. In the course of thermo-mechanical cycling, the formation of a neck during the second tensile deformation was repeatedly detected for SPOSS-PUs with higher PCL network chain length; in the subsequent recovery process the specimens even exhibited the highest total strain recoverability. Finally, gradual strain release could be achieved at temperatures below the PCL melting transition through the selection of up to four temperature holding steps, at which every time stable shapes were formed. KW - Shape memory polymer KW - Active polymer KW - Triple-shape polymer KW - Hybrid star-shaped polymer KW - POSS-polycaprolactone polyurethanes KW - Thermo-mechanical properties PY - 2012 DO - https://doi.org/10.1039/c1sm06474f SN - 1744-683X VL - 8 IS - 4 SP - 965 EP - 972 PB - RSC Publ. CY - Cambridge AN - OPUS4-25260 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pretsch, Thorsten T1 - Neue Möglichkeiten mit Formgedächtnispolymeren T2 - Intelligente Materie - Funktionswerkstoffe und smarte Oberflächen für Design und Produktentwicklung, TSB Technologiestiftung Berlin CY - Berlin, Germany DA - 2013-01-23 PY - 2013 AN - OPUS4-27441 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hättig, J. A1 - Bräuer, W. A1 - Pretsch, Thorsten T1 - Scharfes Gedächtnis einprogrammiert - Thermoplastisches Polyurethan N2 - Auch Kunststoffe können sich erinnern. Das zeigt das Beispiel eines neuen thermoplastischen Polyurethans. Das Formgedächtnispolymer kann vorübergehend in einem deformierten Zustand fixiert und dann wieder nahezu in seine ursprüngliche Gestalt zurückverwandelt werden. Einsatzchancen hat es unter anderem im Markenschutz und Maschinenbau sowie in der Textil-, Sport-, Freizeit- und Spielzeugindustrie. KW - Thermoplastisches Polyurethan (TPU) KW - Poly(ester urethan) KW - Desmopan KW - Formgedächtnispolymer KW - Shape memory polymer KW - Folientunnel KW - Smarte Etiketten KW - TPU Etiketten KW - Fälschungssicher KW - Smartphone KW - QR code PY - 2013 UR - http://www.kunststoffe.de/KU111219 SN - 0023-5563 VL - 1 SP - 56 EP - 59 PB - Hanser CY - München AN - OPUS4-27650 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hättig, J. A1 - Bräuer, W. A1 - Pretsch, Thorsten T1 - Programmed to have a keen memory - Thermoplastic polyurethane N2 - Plastics can also remember things. This is made clear by a new thermoplastic polyurethane. The shape memory polymer can be temporarily fixed in a deformed state and then converted back almost entirely into its original shape. Potential applications exist in trademark protection and mechanical engineering as well as in the textile, sports, leisure and toy industries. KW - Thermoplastic polyurethane KW - Poly(ester urethane) KW - Desmopan KW - Shape memory polymer KW - Self-deployable structures KW - Smart tags KW - TPU labels KW - Greenhouse-like film tunnels KW - QR codes KW - Product and brand protection PY - 2013 UR - http://www.kunststoffe-international.com/PE111219 SN - 1862-4243 VL - 1 SP - 39 EP - 41 PB - Hanser CY - München AN - OPUS4-27651 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pretsch, Thorsten A1 - Ecker, Melanie T1 - Deformable QR Codes with Shape Memory Functionality T2 - E-MRS 2012 Spring Meeting, Symposium Q CY - Strasbourg, France DA - 2012-05-14 PY - 2012 AN - OPUS4-25891 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pretsch, Thorsten A1 - Bothe, Martin T1 - Actuation behavior of a thermo-responsive elastomer under constant load T2 - E-MRS 2012 Spring Meeting, Symposium Q CY - Strasbourg, France DA - 2012-05-14 PY - 2012 AN - OPUS4-25892 LA - deu 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 - CONF A1 - Pretsch, Thorsten T1 - Degradation, functional stability and protection of a shape memory polymer T2 - 1st International Workshop for Young Scientists CY - Tsukuba, Japan DA - 2008-07-22 PY - 2008 AN - OPUS4-17942 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pretsch, Thorsten T1 - Shape Memory Polymers - Characteristics, Ageing & Testing T2 - IMRE Seminar, Institute of Materials Research and Engineering CY - Singapore DA - 2008-11-21 PY - 2008 AN - OPUS4-18459 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pretsch, Thorsten A1 - Müller, Werner T1 - Geosynthetic drain elements of landfill capping systems: long-term water flow capacity and long-term shear strength T2 - 8th International Conference on Geosynthetics CY - Yokohama, Japan DA - 2006-09-18 PY - 2006 AN - OPUS4-16416 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pretsch, Thorsten ED - Teruo Kishi, ED - Thomas Böllinghaus, ED - Masaki Kitagawa, ED - Jürgen Lexow, 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 - JOUR A1 - Ecker, Melanie A1 - Pretsch, Thorsten T1 - Durability of switchable QR code carriers under hydrolytic and photolytic conditions N2 - Following a guest diffusion approach, the surface of a shape memory poly(ester urethane) (PEU) was either black or blue colored. Bowtie-shaped quick response (QR) code carriers were then obtained from laser engraving and cutting, before thermo-mechanical functionalization (programming) was applied to stabilize the PEU in a thermo-responsive (switchable) state. The stability of the dye within the polymer surface and long-term functionality of the polymer were investigated against UVA and hydrolytic ageing. Spectrophotometric investigations verified UVA ageing-related color shifts from black to yellow-brownish and blue to petrol-greenish whereas hydrolytically aged samples changed from black to greenish and blue to light blue. In the case of UVA ageing, color changes were accompanied by dye decolorization, whereas hydrolytic ageing led to contrast declines due to dye diffusion. The Michelson contrast could be identified as an effective tool to follow ageing-related contrast changes between surface-dyed and laser-ablated (undyed) polymer regions. As soon as the Michelson contrast fell below a crucial value of 0.1 due to ageing, the QR code was no longer decipherable with a scanning device. Remarkably, the PEU information carrier base material could even then be adequately fixed and recovered. Hence, the surface contrast turned out to be the decisive parameter for QR code carrier applicability. KW - Beständigkeit KW - Thermoplastisches Polyurethan (TPU) KW - Poly(ester urethan) KW - Formgedächtnispolymer KW - UVA Alterung KW - Hydrolytische Alterung KW - Michelson contrast KW - Shape memory polymer KW - Smarte Etiketten KW - TPU Etiketten KW - Fälschungssicher KW - Smartphone KW - QR code KW - Polymerveredlung KW - Färbeverfahren KW - Lasergravur PY - 2013 DO - https://doi.org/10.1088/0964-1726/22/9/094005 SN - 0964-1726 SN - 1361-665X VL - 22 IS - 9 SP - 094005-1 - 094005-10 PB - Institute of Physics Publ. CY - Bristol AN - OPUS4-28986 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pretsch, Thorsten T1 - Polymere mit Formgedächtnis T2 - WTT-Kooperationsforum, Produkt- und Plagiatsschutz, Berlin Partner für Wirtschaft und Technologie CY - Berlin, Germany DA - 2013-09-20 PY - 2013 AN - OPUS4-29107 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ecker, Melanie A1 - Pretsch, Thorsten T1 - Multifunctional poly(ester urethane) laminates with encoded information N2 - Solvent-cast films from shape memory poly(ester urethane) (PEU) containing different weight contents of microencapsulated thermochromic pigments (T-PIGs) were prepared by drying in air. Spectrophotometric investigations unveiled that gradual loading with T-PIG black resulted in continuous darkening of the films up to filler contents of 20 wt%, accompanied by a steady enhancement of thermochromic properties. Taking this composition as standard, PEU films equipped with T-PIG black, blue and red were deposited atop PEU plaques to obtain laminate structures. Herein, the cover layer thickness (100 ± 5 µm) and the good dispersion of T-PIGs inside the polymer matrix were verified by scanning electron microscopy. Machine-readable information carriers were prepared by laser engraving quick response (QR) codes into the cover layer of the laminates and subsequently cutting cuboidal samples therefrom. Finally, thermo-mechanical programming of the QR code carriers was applied to randomly distort the code patterns, thus rendering them unreadable. Upon heating, surface decolorization and shape recovering occurred; during the ensuing cooling, the surface color and contrast reappeared whereupon the QR codes could be read out. Spectrophotometric, calorimetric and thermo-mechanical investigations gave evidence that the color switching temperature of the T-PIGs roughly coincided with the melting temperature of the ester-based switching segment and thus with the activation temperature of the shape memory effect. Apart from that unique functionality, manifold design concepts may render information carriers difficult-to-copy. Therefore, we anticipate tremendous potential as anti-counterfeiting technology. KW - Stimuli-responsive polymer KW - Shape memory polymer KW - Poly(ester urethane) KW - Microencapsulated KW - Thermochromic pigments KW - Thermo-responsive KW - Thermochromic KW - Shape memory effect KW - Polymer bilayer structure KW - Polymer laminate KW - Paste KW - Gluing KW - Spectrophotometric investigations KW - Calorimetric studies KW - Thermo-mechanical investigations KW - Information carrier KW - Anti-counterfeiting technology KW - Difficult-to-copy PY - 2014 DO - https://doi.org/10.1039/c3ra45651j SN - 2046-2069 VL - 4 IS - 1 SP - 286 EP - 292 PB - RSC Publishing CY - London AN - OPUS4-29652 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bothe, Martin A1 - Pretsch, Thorsten T1 - Bidirectional actuation of a thermoplastic polyurethane elastomer N2 - Herein, we report on how to teach a thermoplastic polyurethane elastomer completely stress-free, bidirectional motion. Briefly spoken, we applied training, consisting of extensive tensile deformation in the specimen's viscoelastic state, initiating deformation-induced crystallization. Once unloaded, thermo-reversible specimen expansion and contraction could be detected. Following the microstructural evolution of such a trained specimen by in situ wide-angle X-ray scattering gave evidence for progressive growth of oriented crystallites during cooling. Upon heating, crystallite melting resulted in structural disorder. Beyond this, modification of the training method was used to introduce a geometrically more complex crystalline order. Here, actuation in the form of a decrease and an increase in sample thickness and specimen twisting and untwisting were witnessed. The novel semi-crystalline polymer actuator highlights an enormous potential for realizing versatile reversible shape changes in elastomers. KW - Bidrectional actuation KW - Thermoplastic polyurethane elastomer KW - Shape memory polymer KW - Training KW - Reversible shape changes KW - In situ wide-angle X-ray scattering KW - Hermann's orientation function KW - Mechanical properties KW - Phase change KW - Polymorphism KW - Poly(ester urethane) KW - Poly(1,4-butylene adipate) KW - Semi-crystallinity KW - Stimuli-sensitive polymer KW - Two-way actuator KW - Two-way shape memory KW - Microscopic model PY - 2013 DO - https://doi.org/10.1039/c3ta13414h SN - 2050-7496 SN - 2050-7488 VL - 1 IS - 46 SP - 14491 EP - 14497 PB - RSC CY - London [u.a.] AN - OPUS4-29641 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pretsch, Thorsten A1 - Jakob, Ines A1 - Müller, Werner T1 - Hydrolytic degradation and functional stability of a segmented shape memory poly(ester urethane) N2 - In order to understand the effects of water and hydrolytic ageing on semi-crystalline poly(ester urethane) and its shape memory functionality, water immersion experiments at elevated temperature have been performed on a model substance and various parameters were monitored: change of the melting/crystallisation temperatures, substantial increase in crystallinity, temperature dependence of the water diffusion coefficient and solubility, hydrogen-bonding index and phase mixing by peak deconvolution of the FT-IR carbonyl region and day-to-day tensile and thermo-mechanical cyclic tensile tests. A rising fraction of freezable water agglomerates in the polymer was found for specimens cooled from the immersion temperature. The degradation process could be divided into three phases: an induction phase, a phase of continuous degradation and a phase of accelerated degradation. Shape recovery remains fairly constant during phase one and decreases slowly during phase two. The increase in crystallinity in phase two is accompanied by an increase in shape fixing ability. KW - Shape memory polymer KW - Poly(ester urethane) KW - Thermo-mechanical properties KW - Hydrolysis PY - 2009 DO - https://doi.org/10.1016/j.polymdegradstab.2008.10.012 SN - 0141-3910 SN - 1873-2321 VL - 94 IS - 1 SP - 61 EP - 73 PB - Applied Science Publ. CY - London AN - OPUS4-18661 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pretsch, Thorsten T1 - Urgency of Standardization for Shape Memory Polymers in Textile Applications T2 - Expert Meeting of CEN/TC 248 WG 31 Smart Textiles CY - Brussels, Belgium DA - 2009-06-30 PY - 2009 AN - OPUS4-19737 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pretsch, Thorsten A1 - Müller, Werner T1 - Shape memory poly(ester urethane) with improved hydrolytic stability N2 - In two hydrolytic degradation studies the tensile (mechanical) and functional (thermo-mechanical) properties of a hydrolysis-stabilized shape memory poly(ester urethane) and its non-stabilized analog were investigated. Hydrolytic degradation was enforced by specimen immersion in de-ionized water at 80 °C. Significant differences in the fundamental shape memory parameters were monitored as function of aging time for the stabilized and non-stabilized polymer. This included the ability to recover strain (shape recoverability) and stress (stress recoverability) on heating after shape programming. Hydrolysis-related mechanical and functional changes were correlated with morphological ones, detected by differential scanning calorimetry (DSC). The shape memory poly(ester urethane), which was protected by a carbodiimide-based hydrolysis stabilizer, revealed significantly improved resistance towards hydrolysis with respect to various mechanical and shape memory parameters. KW - Shape memory polymers KW - Hydrolytic degradation KW - Stabilization KW - Thermo-mechanical properties KW - Poly(ester urethane) KW - Active polymers PY - 2010 DO - https://doi.org/10.1016/j.polymdegradstab.2009.12.020 SN - 0141-3910 SN - 1873-2321 VL - 95 IS - 5 SP - 880 EP - 888 PB - Applied Science Publ. CY - London AN - OPUS4-21270 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller, Werner A1 - Pretsch, Thorsten T1 - Hydrolytic aging of crystallizable shape memory poly(ester urethane): Effects on the thermo-mechanical properties and visco-elastic modeling N2 - The shape memory functionality of a segmented poly(ester urethane) and its hydrolytically aged specimens has been studied by cyclic thermo-mechanical measurements with an imposed strain of 100%. The shape memory effect was triggered by a melting transition in the soft segment phase. Aging was enforced by immersion in hot de-ionized water. In the course of the immersion the tensile properties (secant moduli, stress and strain at yield and break) were impaired by hydrolysis. Advanced specimen embrittlement finally led to rupture during the first thermo-mechanical cycle. This happened after 68 days of aging at 55 °C and correspondingly after 8 days at 80 °C. The residual strain after the first cycle, which was about 25%, increased significantly with aging time. Therefore, the total strain recoverability became ever smaller: aged specimens needed conditioning by at least two cycles for a full development of shape recoverability. Likewise the recovery force decreased continuously. Despite these degradation effects, it was observed that the shape fixity and the cycle-related shape recovery of appropriately conditioned specimens (number of cycles N > 2) remained on a constant high level (at round 100% and between 90% and 100%, respectively) throughout the whole aging period. These observations are discussed within the framework of a simplified model of the behavior of crystallizable shape memory polymers. The amorphous state of the polymer is described by the equation of the linear visco-elastic solid. As for the semi-crystalline state the material is assumed to react elastically with respect to deviations from the configuration, which was frozen up under constraint conditions. The curves of the dependence of the material behavior on aging time at 55 °C match perfectly those at 80 °C when the time axis is adjusted by a factor of 8.5, from which the apparent activation energy for hydrolytic aging in the amorphous state of 82 kJ mol-1 could be deduced. KW - Shape memory polymers KW - Hydrolytic degradation KW - Thermo-mechanical properties KW - Poly(ester urethane) KW - Active polymers PY - 2010 DO - https://doi.org/10.1016/j.eurpolymj.2010.05.004 SN - 0014-3057 SN - 1873-1945 VL - 46 IS - 8 SP - 1745 EP - 1758 PB - Elsevier CY - Oxford AN - OPUS4-21819 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pretsch, Thorsten T1 - Triple-shape properties of a thermoresponsive poly(ester urethane) KW - Triple-shape polymer KW - Active polymer KW - Poly(ester urethane) KW - Thermo-mechanical properties KW - Stimuli-sensitive polymer KW - Shape memory polymer PY - 2010 DO - https://doi.org/10.1088/0964-1726/19/1/015006 SN - 0964-1726 SN - 1361-665X VL - 19 SP - 015006-1 - 015006-7 PB - Institute of Physics Publ. CY - Bristol AN - OPUS4-20761 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pretsch, Thorsten T1 - Durability of a polymer with triple-shape properties N2 - A series of cyclic thermo-mechanical measurements was conducted on segregated poly(ester urethane) to study substantial changes in triple-shape properties as a result of hydrolytic aging (80 °C). Prior to the analysis of aging effects, a concept of triple-shape testing was elaborated, starting with the implementation of two distinct programming units. The first one included a deformation at 60 °C to εm1 = 100% (temporary shape B) and its fixing through soft segment crystallization by cooling to -20 °C under constant strain. The second one consisted of a deformation at -20 °C to εm2 = 200% (temporary shape A) and its stabilization through soft segment vitrification as achieved by cooling to -60 °C under fixed strain constraint. Then, gradual heating of the polymer from below to above its thermal transition temperatures gave two independent shape recovery responses in the reverse order of shape fixing: A → B through passing the glass transition by heating from -60 to 23 °C and B → C (back to the permanent shape), when heating the material from 23 to 60 °C and thus above its soft segment melting temperature. In a progressive approach, the storage of loading history through the sequential fixing of two temporary shapes was proven by the development of shape recovery stresses under constrained environment. With the implementation of the two testing methods several aging-related effects could be detected. Good shape fixing abilities ≥90% for both shapes were found and contrasted by significant changes in shape recoverabilities and stress storage capacities. Further insights derived from differential scanning calorimetry (DSC) measurements, indicating an aging-related growth in soft segment crystallinity, and dynamic mechanical analysis (DMA), suggesting a plasticizer effect of water onto the polymer matrix and that aging favoured an increase in cross-linking density. KW - Triple-shape polymer KW - Shape memory polymer KW - Tandem shape memory polymer KW - Active polymer KW - Poly(ester urethane) KW - Durability PY - 2010 DO - https://doi.org/10.1016/j.polymdegradstab.2010.07.037 SN - 0141-3910 SN - 1873-2321 VL - 95 IS - 12 SP - 2515 EP - 2524 PB - Applied Science Publ. CY - London AN - OPUS4-22551 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bothe, Martin A1 - Pretsch, Thorsten T1 - Two-way shape changes of a shape-memory poly(ester urethane) N2 - Phase-segregated PEU exhibits two-way shape changes under various constant stresses. Most distinct actuation (expansion on cooling and contraction on heating) can be detected between +60 and -20 °C when the maximum stress applied during a thermo-mechanical pretreatment approached the point where deformation-induced crystallization of the PBA soft segment sets in. The driving forces for the strain-related two-way shape changes consist of PBA crystallization and PBA melting-induced entropy elasticity. At low constant stresses (<1.5 MPa), entropy elasticity also contributes to specimen expansion on cooling. The results of multiple- cycling experiments imply that PEU is an appropriate candidate for the fabrication of thermoresponsive actuators working under constant stress conditions. KW - Actuation KW - Entropy elasticity KW - Mechanical properties KW - Phase change KW - Polymorphism KW - Poly(ester urethane) KW - Poly(1,4-butylene adipate) KW - Semi-crystallinity KW - Shape memory polymers KW - Stimuli-sensitive polymers KW - Stress KW - Two-way actuator KW - Two-way shape memory PY - 2012 DO - https://doi.org/10.1002/macp.201200096 SN - 1022-1352 SN - 1521-3935 VL - 213 IS - 22 SP - 2378 EP - 2385 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-27074 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pretsch, Thorsten A1 - Ecker, Melanie A1 - Mirtschin, Nikolaus T1 - Smart Tags carrying QR Codes T2 - 2. Berliner Chemiesymposium, Gesellschaft Deutscher Chemiker - JungChemikerForum CY - Berlin, Germany DA - 2012-04-03 PY - 2012 N1 - Geburtsname von Mirtschin, Nikolaus: Fritzsche, N. - Birth name of Mirtschin, Nikolaus: Fritzsche, N. AN - OPUS4-25797 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pretsch, Thorsten A1 - Mirtschin, Nikolaus T1 - Miniaturization of QR Code Carriers based on Shape Memory Polymer T2 - American Society of Mechanical Engineers ASME 2012 Conference on Smart Materials, Adaptive Structures and Intelligent Systems SMASIS 2012 CY - Stone Mountain, GA, USA DA - 2012-09-19 PY - 2012 N1 - Geburtsname von Mirtschin, Nikolaus: Fritzsche, N. - Birth name of Mirtschin, Nikolaus: Fritzsche, N. AN - OPUS4-26438 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pretsch, Thorsten T1 - Recent progress of switchable information carriers and actuator research T2 - Institutskolloquium CY - Geesthacht-Teltow, Germany DA - 2013-12-13 PY - 2013 AN - OPUS4-29747 LA - deu 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 - TY - CONF A1 - Pretsch, Thorsten T1 - SMP Tagnologies - latest Developments of Information Carriers T2 - K-Messe 2013/K'Fair 2013 (Stand A75, Hall 6) Sharing Dreams, Sharing Value - Be Part Of It CY - Düsseldorf, Germany DA - 2013-10-17 PY - 2013 AN - OPUS4-29209 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mirtschin, Nikolaus A1 - Pretsch, Thorsten T1 - Programming of temperature-memory onsets in a semicrystalline polyurethane elastomer N2 - We demonstrate that phase-segregated poly(ester urethane) (PEU) with crystallizable switching segments of poly(1,4-butylene adipate) (PBA) excels as high-performance temperature-memory polymer. Temperature-memory effects (TMEs) with regard to strain and stress recovering could be programmed by polymer elongation at temperatures below or within the PBA melting transition, followed by cooling under constant stress below the PBA crystallization transition and unloading. Beyond that conventional approach, a novel TME programming route was designed, mostly consisting in specimen elongation and unloading at the same temperature. As a result, an enhanced control over the onsets of strain and stress recovering could be achieved. With these findings, the TME could be exploited to switch quick response (QR) codes in recently developed information carriers from unreadable to readable. We conjecture that such behavior can be programmed into virtually all semicrystalline elastomers and anticipate applicability as label technology to monitor temperature abuse of food and pharmaceuticals. KW - Poly(ester urethane) KW - Shape memory polymer KW - Temperature-memory effect KW - Thermo-responsiveness KW - Information carrier KW - QR code carrier KW - Temperature monitoring label KW - Supervising KW - technology KW - Programming KW - cold chain PY - 2014 DO - https://doi.org/10.1021/ma501171p SN - 0024-9297 SN - 1520-5835 N1 - Geburtsname von Mirtschin, Nikolaus: Fritzsche, N. - Birth name of Mirtschin, Nikolaus: Fritzsche, N. VL - 47 IS - 17 SP - 5952 EP - 5959 PB - American Chemical Society CY - Washington, DC AN - OPUS4-31381 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pretsch, Thorsten T1 - Gegen Produktpiraterie: Hightech-Etiketten mit eingebautem Farbschalter T2 - 4. Erfahrungsaustausch Marktüberwachung ERFA MÜ 2014 CY - Berlin, Germany DA - 2014-06-04 PY - 2014 AN - OPUS4-30754 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pretsch, Thorsten T1 - Recent Advances in the Development of Switchable Information Carriers T2 - Institutskolloquium am Fraunhofer ICT-IMM CY - Mainz, Germany DA - 2014-04-02 PY - 2014 AN - OPUS4-30514 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pretsch, Thorsten T1 - Vorteile neuartiger Leergutrücknahmesysteme T2 - Wincor Nixdorf International Seminar CY - Ilmenau, Germany DA - 2014-07-01 PY - 2014 AN - OPUS4-31010 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pretsch, Thorsten T1 - Hightech-Etiketten gegen Produktpiraterie T2 - Wincor Nixdorf International Seminar CY - Ilmenau, Germany DA - 2014-07-01 PY - 2014 AN - OPUS4-31023 LA - deu 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 - GEN A1 - Ecker, Melanie A1 - Pretsch, Thorsten ED - Udomkichdecha, W. ED - Böllinghaus, T. 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 - CONF A1 - Pretsch, Thorsten T1 - About the effects of hydrolytic aging on the mechanical and thermo-mechanical properties of a non-stabilized and a Stabaxol-stabilized shape memory polymer T2 - 28th Polymer degradation discussion group meeting CY - Sestri Levante, Italy DA - 2009-09-06 KW - Shape memory polymer KW - Thermo-mechanical properties KW - Active polymer KW - Stimuli-sensitive polymer KW - Poly(ester urethane) KW - Stabilizer KW - Ageing behaviour KW - Stabaxol PY - 2009 SP - 32 EP - 34 PB - Elsevier AN - OPUS4-19864 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pretsch, Thorsten T1 - Thermo-mechanical Effects of hydrolytic Aging on an active Polymer with Triple-Shape Properties T2 - Polychar 18 - World Forum on Advanced Materials CY - Siegen, Germany DA - 2010-04-07 PY - 2010 AN - OPUS4-21138 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mya, K.Y. A1 - Gose, H.B. A1 - Pretsch, Thorsten A1 - Bothe, Martin A1 - He, C. T1 - Star-shaped POSS-polycaprolactone polyurethanes and their shape memory performance N2 - Star-shaped polyhedral oligomeric silsesquioxane (SPOSS)-based multi-arm poly(ε-caprolactones) (PCLs) with various arm lengths were synthesized by ring opening polymerization of ε-caprolactone. Increasing the PCL arm lengths was observed to increase the melting temperature and also the melt crystallization temperature in SPOSS-PCLs. Star-shaped POSS-PCL polyurethanes (SPOSS-PUs) were then prepared by cross-linking SPOSS-PCLs with hexamethylene diisocyanate (HMDI) and their shape memory (SM) behaviour was determined. For this purpose two cyclic thermo-mechanical testing concepts with similar programming (deformation and shape fixing) but different recovery strategies (free strain versus fixed-strain constrained stress recovery) were used and the synthesized polymers were systematically investigated around the crystallization and melting temperatures of PCL. SPOSS-PU with the highest POSS content exhibited remarkable cycles-averaged (N = 2–5) shape fixities and strain recoverabilities of 98% and stress recoverabilities close to 100%. The main structural factors that were expected to reduce the SM performances with increasing PCL arm lengths were a lowering of cross-link density (content of octasubstituted POSS) and an increase in chain flexibility/molecular mobility. KW - Shape memory polymer KW - Active polymer KW - Hybrid star-shaped polymer KW - POSS-polycaprolactone polyurethanes KW - Thermo-mechanical properties PY - 2011 DO - https://doi.org/10.1039/c0jm04459h SN - 0959-9428 SN - 1364-5501 VL - 21 IS - 13 SP - 4827 EP - 4836 PB - Royal Society of Chemistry CY - Cambridge AN - OPUS4-23479 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pretsch, Thorsten T1 - About the effects of hydrolytic aging on the mechanical and thermomechanical properties of a non-stabilized and a Stabaxol-stabilized shape memory polymer T2 - 28th meeting of the Polymer Degradation and Discussion Group CY - Sestri Levante, Italy DA - 2009-09-06 PY - 2009 AN - OPUS4-20036 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 - CONF A1 - Pretsch, Thorsten T1 - Shape Memory Polymer Research @ BAM T2 - Seminar Institut für Mikrotechnik Mainz CY - Mainz, Germany DA - 2010-10-11 PY - 2010 AN - OPUS4-22148 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pretsch, Thorsten T1 - Thermoplastic Poly(ester urethane): Durability, Triple-Shape Properties and one new Field of Application T2 - Polymer Degradation Discussion Group, 29th PDDG Conference CY - Sestri Levante, Italy DA - 2011-09-05 PY - 2011 AN - OPUS4-24290 LA - deu 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 -