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 43 for “"Polymer Melt"”.
-
Unexplored Dimensions of Processing Phase Inversion during Polymer Melt Blending
Blending of multiple polymers is a commonly utilized strategy to achieve a balance of a variety of critical properties of polymeric materials, such as strength, toughness, thermal stability, ductility, etc. Although exhaustive studies have helped understand the thermodynamic basis for the phase …
-
Hydrodynamic lubrication and coating of wire using a polymer melt during drawing process.
… the lubrication and other effects of employing a polymer melt as the lubricant during the wire drawing process. The device is heated to convert the polymer feed into a viscous melt and the pressure required is generated by a hydrodynamic action produced by the motion of the wire. On the basis of …
-
Molecular Insights on the Boundary Behavior of Liquids
… the translational diffusion of molecularly thin polymer melt. While simulations have been performed, to my knowledge no direct measurements exist yet of polymer melt diffusion in molecularly-thin films. This is due to the lack of proper experimental tools and the large number of variables …
-
Lubrication Forces in Polydimethylsiloxane (PDMS) Melts
… flow properties of polydimethylsiloxane (PDMS) melts at room temperature were studied by measurement of lubrication forces using an Atomic Force Microscopy (AFM) colloidal force probe. A glass probe was driven toward a glass plate at piezo drive rates in the range of 12 – 120 μm/s, which …
-
Coarse-grained simulations to predict structure and properties of polymer nanocomposites
Polymer Nanocomposites (PNC) are a new class of materials characterized by their large interfacial areas between the host polymer and nanofiller. This unique feature, due to the size of the nanofiller, is understood to be the cause of enhanced mechanical, electrical, optical, and barrier properties …
-
Single wall carbon nanotubes as viscosity modifiers in polypropylene matrix nanocomposites
… viscosity when nanotubes were added into the polymer melt, this work focused on modifying the sidewall profile of the SWNTs and manipulating their configuration in the polymer matrix before subjecting them to rheological testing. Fluorinated single-walled nanotubes (F-SWNTs) played a critical …
-
Interactions and Dynamics of Soft Materials
… large part of my dissertation is related with polymer interfacial dynamics. As one of the center topics of polymer physics, many models have been generated to understand polymer dynamics in bulk solutions and in melt. However, to study the dynamics of polymer at the interfaces is more …
-
Computational modeling of fiber reinforced composites melt flow in nozzle extrudate for polymer deposition additive manufacturing.
… properties of processed composite materials for polymer deposition additive manufacturing is critical, especially in the recent-emerging Large Area Additive Manufacturing (LAAM) polymer composite deposition technology. This dissertation aims to broaden the knowledge of how manufacturing inputs …
-
Experimental Modeling of Twin-Screw Extrusion Processes to Predict Properties of Extruded Composites
… extrusion is used to compound fillers into a polymer matrix in order to improve the properties of the final product. The resultant properties of the composite are determined by the operating conditions used during extrusion processing. Changes in the operating conditions affect the physics of …
-
Optimal design and analysis for polymer extrusion and molding
… which can be used to improve the production of polymer components manufactured via the extrusion, injection molding, and compression molding processes. The design methodology employs polymer process modeling, design sensitivity analysis, and numerical optimization. It is applicable to systems …
-
Gas assisted injection moulding: Experiment and simulation. Industrial machine experimental studies of the effect of process variables on gas bubble formation, and with simulation based upon a pseudo-concentration method.
… here the penetration of a gas bubble through the polymer melt is of interest. A 3D fi nite element implementation of a pseudo concentration method is employed to simulate the primary penetration of the gas bubble. The wall thickness prediction is an important result since the extent of bubble …
-
The Antioxidant Function of Dithiophosphoryl Compounds in Rubbers
… mechanochemically undershearing condition in the polymer melt resulted in a lowerextent of binding. The adduct. however made. became unboundduring vulcanization. All the dithiophosphoryl compoundsexamined were found to exhibit a pro-oxidant effect in conventionalaccelerated sulphur vulcanizates, …
-
The kinetics of drug dissolution in polymers during hot-melt extrusion
… important and widely used continuous process in polymer processing for over one hundred and fifty years. However, it has only been recently applied and adopted by the pharmaceutical industry to prepare solid oral dosage formulations with increased bioavailability for the poorly-water soluble …
-
Role of surface chemistry in sub-Einstein rheology of nano-composites
… resulting from the addition of nano-fillers to polymer melts approximately 2-10 nm diameter have been reported. Here we explore the intrinsic viscosity of polyhedral oligomeric silisequioxane (POSS) particles of approximately 1.6-2.5 nm diameters as a function of polymer molecular weight. These …
-
From Nanoplates to Bottlebrushes: Engineering Thermodynamics in Polymer Nanocomposites
Polymer nanocomposites (PNCs) represent a diverse class of materials where manipulating design parameters is crucial for tailoring material properties. Of utmost importance for nanocomposites is nanoparticle dispersion, which is affected by the nanoparticle itself as well as the overall polymer …
-
Asymptotically nonliner oscillatory shear: theory, modeling, measurements and applications of nonlinear elasticity to stimuli-responsive composites
… crosslinked networks of synthetic and biological polymers, exhibit a nonlinear rheological response to mechanical deformation. Oscillatory shear is a popular deformation protocol for viscoelastic characterization, both linear and nonlinear, the latter referred to as large amplitude oscillatory …
-
Thermodynamic Investigation of the Interaction between Polymer and Gases
… the interaction between blowing agents and polymer matrix. Existing theoretical model was further developed to accommodate the polymer and blowing agent under study. The obtained results are not only useful for the optimization of the plastic foam fabrication process but also provides a …
-
Ft-Ir Study of the Dynamics of Entangled Polymer Melts
The dynamics of entangled polymer melts have been examined using polarized Fourier-Transform infrared (FT-IR) spectroscopy. Based on the reptation model, the motion of a chain in the presence of topological entanglements is that of a one dimensional random walk along the chain contour. This motion …
-
Development of biodegradable microfluidic networks for tissue engineering
… soft lithography, and traditional polymer processing are combined to develop a fully biodegradable microfabrication platform using poly(DL-lactic-co-glycolic) acid (PLGA 85:15). First, micron scale structures fabricated on silicon substrates are transferred into the surface of …
-
Synthesis and Non-Covalent Interactions of Novel Phosphonium-Containing Polymers
… activity. Ionic aggregation in phosphonium-based polymers provides thermoreversible crosslinks, ideal for reversible self-assembly, self-healing, and smart response. In polymers, these ionic functionalities aggregate, providing improved moduli, and altering the size and structure of ionic …
Page 1 of 3