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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 3689 for “"Polymers"”.
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Large Polymers that Behave Like Small Polymers
… thermal and mechanical robustness. Synthesizing polymers with novel architectures can overcome these challenges by creating materials with a unique set of properties and thus eliminating the trade-off between chain flexibility and desirable macromolecular physical properties. Detailed within this …
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Functionalised polymers
Synthetic routes to polymers possessing functional groups were studied. Direct functionalisation of poly(vinyltoluene) by lithiation and carboxylation resulted in the expected carboxylic acid but reaction was complicated by the production of a mixture of products. Reaction occurred both at the …
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Studies of Sustainable Polymers: Novel Lignins to Reprocessable Polymers
This dissertation includes two research topics. This first topic focuses on fundamental studies of monolignols and lignin, including polymerization and degradation. The second part reports a polymeric material that was crosslinked but can be reprocessed. In order to understand lignin from a …
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Polymers at membranes
Die Oberfläche biologischer Zellen besteht aus einer Lipidmembran und einer Vielzahl von Proteinen und Polymeren, die in die Membran eingebaut sind. Die Beeinflussung der Membran durch Polymere, die mit einem Ende an der Membran verankert sind, wird im Rahmen dieser Arbeit anhand eines …
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Improved superabsorbent polymers
… of a class of acrylic-based superabsorbent polymers. The techniques of inverse suspension and solution polymerisations were used for synthesis. Each absorbent was mainly characterised by its equilibrium capacity of water absorption and by the rate of absorption. The swelling characteristics …
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Melting of polymers
The project set out to investigate the relative effectiveness of thermal conductive heating (from external resistance heaters) and viscous heating in the heating (and melting) of low density polyethylene. A model system was used in order to simplify the mathematical analysis. A theory was developed …
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Novel hydrogel polymers
… may be conveniently described as hydrophilic polymers that are swollen by, but do not dissolve in water. In this work a series of copolymer hydrogels and semi-interpenetrating polymer networks based on the monomers 2-hydroxyethyl methacrylate, N-vinyl pyrrolidone and N'N' dimethyl acrylamide, …
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Novel hydrogel polymers
Hydrogels are a unique class of polymers which swell, but do not dissolve in water. A range of 2-hydroxyethyl methacrylate based copolymer hydrogels have been synthesised and are described in this thesis. Initially, hydrogels were synthesised containing acryloylmorpholine, N,N-dimethyl acrylamide …
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Hyperbranched polymers and Haag type dendrimers for the molecular imprinting of polymers
A molecularly imprinted polymer was synthesized using both hyperbranched polyglycerol and Haag type polyether dendrons with estradiol as a core. The attachment of the polyether dendron created a dendrimer that had 64 allyl groups available for crosslinking. Completion of the crosslinking of the …
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Applications of ROMP Polymers
… polymer, named solvent programmable polymers (SPPs), was developed by ring-opening metathesis polymerization (ROMP) based on monomers containing recognition groups that display restricted rotation. We could modulate the binding properties of the SPPs by heating in polar or non-polar …
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Polymers for DNA Binding
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Synthesis of Conjugated Polymers
Conjugated polymers (CPs) are a unique class of materials because they possess the electronic properties of semi-conductors and processability of polymers. Their electronic and optical properties can be controlled by their chemical structures and conjugation length.To enhance the electron affinity …
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Inorganic/organic hybrid polymers
… characterise a range of inorganic/organic hybrid polymers containing pendant vinyl groups and to study their uses as possible fire retardants. The work consisted of several parallel strands: the synthesis of organically modified silicas; the preparation of vinyl containing silsesquioxanes based on …
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Mass transport in polymers
… overcome lack of barrier properties in common polymers that forbids their application in sensitive applications as food packaging. The final goal of obtaining a membrane almost impermeable to oxygen leads to experimental times out of reach. Hence, a simple model was developed in order to …
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Chemical modification of polymers
Based on the knowledge of PVC degradation and stabilisation, chemical modifications were imposed on degraded PVC and raw PVC with the aim of obtaining non-migrating additives. The modifications were carried out mainly in the presence of dibutyl maleate (DBM), and the resulting polymer contained …
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Polymers, Nanoparticles and Phospholipids
In addition, we find binding of charged nanoparticles to the outer surface of phospholipid liposomes produces particle-stabilized liposomes that repel one another and do not fuse. Subsequently, the volume fraction can be raised as high as ∼50%, reversibly, still without fusion. In studies of …
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Some Metal Containing Polymers
Made available in DSpace on 2015-05-12T17:02:37Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 5900530.PDF: 5711320 bytes, checksum: b4cc624df60ee28324ba9574e539d774 (MD5) Previous issue date: 1958
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ELASTOCALORIC EFFECTS IN POLYMERS
… the environment and energy inefficient. Elastic polymers (elastomers) are a new group of elastocaloric materials that promise giant elastocaloric effects at room temperature near conformational phase transitions, due to large changes in their degree of crystallinity that can be driven reversibly …
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Heavily fluorinated electronic polymers
… shown to give exclusively fluorous-phase soluble polymers, the syntheses of which were achieved by fluorous biphasic polymerization conditions. Perfluoroalkylated PPEs were found to have excellent fluorescence quantum yields and photophysical and chemical stability, and were used to demonstrate …
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