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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 27 for “"Shape Memory Properties"”.
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Application-oriented development of thermoplastic polyurethanes with shape memory properties
Shape memory polymers (SMPs) are smart materials, that are capable of changing their shape in response to an external stimulus, typically a change in (ambient) temperature. This change in shape is commonly triggered after a thermomechanical treatment, enabling them to return to their original …
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Amorphous, multi-phase polymer network systems with shape memory properties by photopolymerization
… amorphous, covalent polymer network systems with shape-memory properties. The highest glass transition temperature of these networks serves as switching temperature Ttrans for the shape-memory effect. For potential applications in medicine, the material is designed to be degradable in …
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Cu-based shape memory microwires : towards complex structures
Shape memory alloys are a distinctive type of material that exhibits the fascinating properties of the shape memory effect and superelasticity. Shape memory properties are characterized by the diffusionless phase transformation between austenite and martensite that can be thermally or stress …
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Entwicklung photosensitiver Polymernetzwerke mit Formgedächtniseigenschaften
In the present thesis a polymer system with shape-memory properties is developed. The shape-memory effect is triggered by irradiation of the polymer with UV-light with different wavelength. The irradiation causes a reversible change of network density of the elastomer. By that, the elastic …
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Aging Effects in Copper-Zinc-Aluminium Shape Memory Alloys (Martensite, Bainite)
… alloys causes deterioration and instability of shape memory properties, even at moderate temperatures. These aging effects have been studied by electrical resistivity measurements and bend tests. The corresponding changes in microstructure were investigated using optical microscopy, transmission …
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Modification and Integration of Shape Memory Alloys Through Thermal Treatments and Dissimilar Metal Joining
While Shape Memory Alloys (SMAs) have been the topic of numerous studies throughout their history, over fifty years after the first observation of the shape memory effect, their widespread use is still limited by the complexity of tuning the shape memory response and furthermore the difficulty in …
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Effects of Polybenzoxazine on Properties of Shape-Memory Polyurethanes with Glassy and Crystalline Soft Segments
Shape memory polymers (SMPs) have attracted significant attention from both industrial and academic fields because of their useful and fascinating functional preperties. Of particular interests are shape memory polyurethane (SMPUs), which have strong potential in biomedical and consumer …
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Shape memory ceramics in small volumes
Shape memory ceramics rely on martensitic transformations which are similar to those found in metallic shape memory materials, but ceramics offer several advantages over metals such as higher operating temperatures and larger transformation stresses. However, polycrystalline shape memory ceramics …
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Bioabbaubare Polymernetzwerke mit Formgedächtniseffekt als Matrix für Wirkstofffreisetzungssysteme
… based on biodegradable polymer networks with shape-memory properties for controlled delivery of low molecular mass drugs. A polymer network based on oligo[(e-hydroxycaproate)-co-glycolate]dimethacrylates and butylacrylate with a semi-crystalline switching segment is used for the systematic …
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Temperature and Water Responsive Shape Memory Polymers for Soft Tissue Expansion
A biodegradable thermoplastic shape memory polymer which can be used for 3D printing patient specific soft tissue expanders was synthesized and characterized. The bottlebrush polymer with Poly (vinyl alcohol) backbone and polyurethane side chains exhibited shape memory effect. Using an …
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Solid state NMR for advanced materials characterization
… distributed heterogeneities and the macroscopic properties of materials. This information is essential in order to design materials with improved properties. Spin-diffusion NMR represents an established method to investigate domain sizes and morphology of heterogeneous polymers. General …
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Exploring crystallographic compatibility in polycrystalline Cu-based shape-memory alloys
Shape-memory alloys (SMAs) are a class of materials that can recover from apparent permanent strain (on the order of 5%) due to a solid-to-solid phase transformation. It has been recently suggested that SMAs satisfying a set of so-called cofactor conditions possess perfect interface compatibility …
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Shape Memory Alloys for small scale actuation
Shape Memory Alloys (SMAs), materials that can undergo a fully recoverable strain change due to a thermal cycle, and which can be produced in a form that is superelastic are only utilized limitedly. In this thesis, I investigated the relationship between the material properties of shape memory …
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4D Printing Shape Memory Polymers for Biomedical Applications
… development of 3D printing techniques using shape-memory polymers (SMPs) hascreated potentials for creating dynamic, three-dimensional structures that can be produced rapidly and be customized for specific and complex architectures. These qualities have made 3D printing a popular fabrication …
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Structure-Property Relationships in Novel Electrospun Composites for Advanced Applications
<p>Active polymeric materials that alter shape in response to an external stimulus offer unique avenues for the design and study of dynamic structures. This research focused on developing elastomeric polymer composites with multiple functionalities by exploring the design and properties for various …
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Biodegradable Thermoplastic Elastomers and Smart Composites
… hard segment ratio, the thermal and mechanical properties could be controlled. Increasing the comonomer (glycolide or d,l-lactide) content caused a decrease in the thermal and mechanical properties, while increasing POSS caused an increase in these properties. Overall, the synthesized …
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Grain constraint and size effects in shape memory alloy microwires
Shape memory alloys exhibit interesting and useful properties, such as the shape memory effect and superelasticity. Among the many alloy families that have been shown to exhibit shape memory properties the ones based on copper are interesting because they are relatively inexpensive and show …
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Amorphe bioabbaubare Poly(esterurethan)netzwerksysteme mit Formgedächtniseigenschaften
… and covalently crosslinked polymer systems with shape-memory properties. The macroscopic properties of the polymer networks can be tailored by variation of molecular parameters such as chemical composition, crosslink density or functionality of the crosslink points. The hydrolytic degradable …
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Development of Flexible Pressure and Strain Sensors for Electronic Skin Applications
… technique. The developed fibers possess shape memory properties which contribute to an enhanced recovery of the sensor after undergoing large deformations. Furthermore, using a thermoplastic elastomer, strain sensors with stretchability up to 1000%, high sensitivity and low hysteresis are …
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An investigation into the influence of microstructural condition on the superelastic behaviour in Ti-Nb-based alloys.
Ti-Nb based alloys show superelastic and shape memory properties over a wide range of temperatures, making them attractive for industrial applications. However, within the literature there are significant variations in the reported martensite start temperatures that have not been rationalised. To …
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