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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 12 of 12 for “"segmented polyurethanes"”.
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Segmented polyurethanes containing diacetylene units in multiple molecular environments
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1996.
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Design, synthesis and characterization of side chain liquid crystal segmented polyurethanes
Side chain liquid crystal polyurethanes are liquid crystal elastomers with the potential to couple mechanical stress fields with optical changes brought on by liquid crystal alignment. These materials excite interest because they are the first thermoplastic liquid crystal elastomers (LCTPEs) that …
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Synthesis and Properties of Novel Triptycene-containing Segmented Polyurethanes and Semicrystalline Polysulfone-polyester Multiblock Copolymers
Segmented copolymers are important polymers with attractive properties and wide applications. In this dissertation, segmented polyurethanes containing triptycene units and multiblock copolymers containing poly(arylene ether sulfone) (PAES) and poly(1,4-cyclohexyldimethylene terephthalate) (PCT) …
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PEO-containing copolymers as polyurethane soft segments in the development of high performance materials
Silk-inspired segmented polyurethanes containing flexible, hydrophilic segments with crystalline and liquid crystalline moieties were developed to mimic the hierarchical morphology of the continuous domain in and the superior mechanical properties of native spider silk. A series of polyurethane …
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Synthesis and Properties of Ion-Containing Block and Segmented Copolymers and Their Composites
Ion-containing segmented polyurethanes exhibit unique morphology and physical properties due to synergistic interactions of electrostatic, hydrogen bonding, and hydrophobic interactions. A fundamental investigation on a series of well-defined ion-containing polyurethanes elucidated the influence of …
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Determining soft segment structure-property effects in the enhancement of segmented polyurethane performance
Liquid Crystalline Elastomer (LCE)-inspired segmented polyurethane elastomers possessing widely different extents of ordering were created to mimic the hierarchical structure of the continuous matrix and superior mechanical performance of spider silk fibers. The silk's remarkable toughness …
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Structure–Property Relationships Of: 1) Novel Polyurethane and Polyurea Segmented Copolymers and 2) The Influence of Selected Solution Casting Variables on the Solid State Structure of Synthetic Polypeptide Films Based on Glutamate Chemistry
… dissertation concern the characterization of segmented polyurethanes and polyureas synthesized without the use of chain extenders'molecules that are typically used to promote a microphase separated morphology that gives these materials their useful characteristics. Polyurethanes in which a …
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Structure-property relationships in segmented copolymers
The structure-property relationships for various segmented copolymers were investigated. A number of mechanical and thermal characteristics were determined. The morphology was characterized by SAXS with respect to size and dispersion of domains; degree of phase separation and the domain interfacial …
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Force-induced mechanochemical reactions in polymeric systems
… the change in SP-MC equilibrium to be studied. Segmented polyurethane (SPU) is a phase separated copolymer of a soft and hard segment PU. The incorporation of the SP mechanophore into PU by step growth polymerization allows for controlled placement of SP in either the soft or hard domain. Upon …
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Investigation of the Influence of Selected Variables on the Solid State Structure-Property Behavior of Segmented Copolymers
Segmented copolymers are a commercially important class of materials that are utilized in a wide variety of applications. In these systems a relatively large number of variables such as backbone chemistry, segment molecular weight, and the overall molecular weight of the copolymer can be …
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Design of Functional Polyesters for Electronic and Biological Applications
… bisphenol-A replacements and ioncontaining segmented polyurethanes aided in identifying benchmark polymers, including limitations, challenges, and future needs. Structure-property-morphology relationships were investigated to evaluate the polymers for success in the proposed applications as …
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Synthesis and Characterization of Hydrophilic-Hydrophobic Poly (Arylene Ether Sulfone) Random and Segmented Copolymers for Membrane Applications
… and poly(ethylene oxide)-containing random and segmented copolymers for reverse osmosis and gas separation membranes. The second chapter of this dissertation describes synthesis of disulfonated poly(arylene ether sulfone) random copolymers with oligomeric molecular weights that contain …