Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 130 for “"Urethane"”.
-
Non-isocyanate routes to urethane-polymers
The conventional synthetic route to urethane polymers involves the use of hazardous dflsocyanates which are synthesised using phosgene, the use of which produces a significant chlorine-waste stream. The processing of high molecular mass specialty polyurethanes regularly requires the use of organic …
-
UV-initiated synthesis of novel urethane polymers
… use of this reaction for the production of polyurethane coatings through a photopolymerisation reaction with isocyanates has been discovered. The nitrite esters were synthesised from nitrous acid produced in situ from sodium nitrite and sulfuric or nitric acid. Yields of 79.5 and 76.4% were …
-
Synthesis and characterization of alternating poly(amide urethane)s
… with the preparation of alternating poly(amide urethane)s which might be of interest for the manufacture of powder coatings. The synthesis of poly(amide urethane)s was performed in environmentally friendly way without using isocyanates or phosgene. The starting materials for the synthesis were …
-
Synthesis and characterization of hyperbranched poly(urea-urethane)s
… aims to synthesize hyperbranched poly(urea-urethane) polymers (HPU) in one-pot method using commercially available monomers which are 2,4-toluylene diisocyanate (TDI) as aromatic diisocyanate and isophorone diisocyanate (IPDI) and 2(3-isocyanatopropyl) cyclohexylisocyanate (IPCI) as …
-
Structure-Process-Property Relationships of Cellulose Nanocrystal Thermoplastic Urethane Composites
… influence of melt processing CNC thermoplastic urethane (TPU) composites and the resulting impact on the mechanical adaptive response. Dynamic mechanical analysis (DMA) fitted with a submersion clamp was used to measure the mechanical softening of the composite while submerged in water. Small …
-
Isocyanate-free synthesis of (functional) polyureas, polyurethanes, and urethane-containing copolymers
… characterization of (functional) polyureas, polyurethanes, and urethane-containing copolymers without using isocyanates or phosgene by step-growth reactions in bulk or solution. An important aspect of this thesis was the use of easily accessible reagents, such as diamines, amino alcohols, …
-
Sleep/wakefulness versus urethane anesthesia: analogous arousal states for respiratory control?
Under light urethane anesthesia, animals cycle through patterns of EEG activity which superficially appear like waking (W), light sleep (LS) and slow-wave sleep (SWS) in the unanesthetized animal, referred to as States I, II and DI, respectively. The major question in this thesis was whether the …
-
Process-Structure-Property Relationships of Cellulose Derivative/Thermoplastic Urethane Polymer Composites
… development of 3D-printable thermoplastic polyurethane (TPU) composites reinforced with hydroxypropyl cellulose (HPC) or cellulose nanocrystals (CNCs), aiming to systematically investigate how formulation, processing, and filler interactions dictate thermal stability, rheological behavior, …
-
Long-term Durability Characterization and Prediction of a Urethane-based Adhesive
… experience. In this work, the behavior of a urethane-based adhesive was characterized and long-term durability predictions were developed as a result of the data collected. The popular T-peel sample geometry has been used extensively in this study to explore the mechanics of a bonded system …
-
Characterization of Structure-Property Relationships of Poly(urethane-urea)s for Fiber Applications
Poly(urethane)s and poly(urethane-urea)s (PUU) are nearly ubiquitous, having been in existence since before the Second World War. Spandex, a poly(urethane-urea) elastomeric fiber, is found in nearly all articles of apparel as well as in an increasing array of other consumer items. The technology …
-
Insights into the behaviour of hydrophobically modified ethoxylated urethane polymers in soft and hard colloid formulation
Hydrophobically modified ethoxylated urethane polymers (HEUR) are used as viscosity modifiers in various formulations, e.g. cosmetics, paints. The HEURS show a complex behaviour in solution owing to the interaction between the hydrophobic segments present in the polymer and other formulation …
-
Kinetics of HO2 abstraction of H atoms from hydrocarbons and thermochemical properties of urethane monomers and radicals
… Entropy and Heat Capacity (T) for Model Urethane Monomers and Corresponding Radicals. Two separate model urethanes (carbamates), Ethyl N Ethyl carbamate [C-C-N-C(O)-OC-C] and N (n-propyl) methylcarbamate [C-C-C-N-C(O)-O-C] are utilized to investigate the thermochemical properties and bond …
-
Development and Implementation of Dispersion Phase Diagrams (DPDs) for Four Different Hydrophobically Modified Ethoxylated Urethane (HEUR) Based Acrylic Paint Systems
… for some hydrophobically modified ethoxylated urethane (HEUR) thickened paint systems that are very similar to commercially used paint formulations. The probing of these phase separated regions includes the careful preparation of each paint sample, physical property testing, as well as new …
Page 1 of 7