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.
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Showing 1 to 20 of 24 for “"polymer interface"”.
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A Study of Heat Transfer at the Cavity-Polymer Interface in Microinjection Moulding. The effects of processing conditions, cavity surface roughness and polymer physical properties on the heat transfer coefficient
This thesis investigates the cooling behaviour of polymers during the microinjection moulding process. The work included bespoke experimental mould design and manufacturing, material characterisation, infra-red temperature measurements, cooling analysis and cooling prediction using commercial …
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Development of an enhanced microstructure–level machining model for carbon nanotube reinforced polymer composites using cohesive zone interface
Carbon nanotube (CNT)–reinforced polymer composites have found numerous applications including their use in light–weight structures, micro–fluidic devices, textiles, actuators, and bio–medical implants. The presence of CNTs in the polymer matrix has been found to influence the machining responses …
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Fundamental Study of the Machinability of Carbon Nanotube Reinforced Polymer Composites
Alignment of CNTs in the polymer matrix is important from a material property improvement stand point. Therefore, a microstructure-based finite element machining model was used to study the effect of CNT orientation on the machining responses. The predicted machining responses for aligned CNT …
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Micromechanics of piezocomposites
… materials engineers have developed piezoelectric-polymer composite materials that enable effective electromechanical properties to be tailored for a specific application. These materials are made by combining conventional piezoelectric ceramics with piezoelectrically passive polymers in a variety …
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Micromechanics of deformation in polymers modified by inorganic and rubber particles
Many structural polymers exhibit brittle behavior at low temperatures and/or high strain rates. It has been shown that the incorporation of rubber and inorganic particles can have significant toughening effects. Previous studies have shown that the particles can alter the matrix morphology at the …
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Surface-enhanced Raman and surface plasmon resonance measurements of Case II diffusion events on the nanometer length scale
… planar films implanted in $\mu$m-scale polymer films. The use of Au rather than Ag metal-island films is shown to eliminate spectral interference resulting from photolytic degradation reported in typical SERS studies of glassy polymers. A sample probe consisting of an Au metal film …
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Crack Healing in Polymers (Fracture, Reptation, Tack)
… development associated with the healing of polymer-polymer interfaces was studied using theoretical and experimental approaches. The healing of crazes in atactic polystyrene (PS) and microvoids in styrene-isoprene-styrene block copolymers was described phenomenologically, from dark-field …
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Multiscale chemomechanics of polymer deformation under contact : predicting structure-property correlations from the bulk to the interphase
The development of nanoscale polymeric materials for mechanical applications necessitates advances in small-volume experimental techniques and analyses that reflect the viscoelastoplastic behavior of such materials. In this thesis, the time-dependence and response of homogeneous engineering …
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Remote optical fiber sensing based on reflectance due to the swelling of polymer particles produced by dispersion polymerization
… pyridine) particles produced by dispersion polymerization were suspended in a hydrogel membrane and used for remote measurements employing fiber optic sensors. The refractive index of poly(4-vinyl pyridine) particles is higher than the refractive index of the hydrogel. At low pH, protonation …
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Nanotube reinforced thermoplastic polymer matrix composites
… make nanotubes attractive reinforcements for polymer matrix composites. However, the structure that makes them desirable also causes highly anisotropic properties and limited reactivity with other materials. This thesis isolates these problems in two separate studies aimed at improving …
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Electrical breakdown and structural characterization in synthetic resins using optical techniques
… material degradation and debonding of the metal/polymer interface with the formation of the first microchannels. A study of tree initiation and growth in the CY1311 epoxy resin details some of the many factors that influence electrical breakdown in resins. The early tree growth is shown to be …
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Bioresorbable Electrospun Tissue Scaffolds of Poly(ethylene glycol-b-lactide) Copolymers for Bone Tissue Engineering
… poly(ethylene glycol) (PEG) into the polymer interface to promote osteoblastic differentiation and (2) controlling topography to direct cell behavior. The novel processing technique of electrospinning allows the fabrication of nanofiber scaffolds with topographical features the size of …
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Advances in experimental methods to probe surface relief grating formation mechanism in photosensitive materials
When azobenzene-modified photosensitive polymer films are irradiated with light interference patterns, topographic variations in the film develop that follow the electric field vector distribution resulting in the formation of surface relief grating (SRG). The exact correspondence of the electric …
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Polydimethylsiloxane Containing Block Copolymers: Synthesis and Characterization of Alternating Poly(Arylene Ether Phosphine Oxide)-B-Siloxane and Segmented Nylon 6,6 -B-Siloxane Copolymers
… siloxane containing, organic-inorganic block copolymers were prepared using different synthetic approaches. The first copolymers were alternating poly(arylene ether phosphine oxide)-poly(dimethylsiloxane) systems, prepared via oligomeric silylamine-hydroxyl reactions. Secondly, segmented nylon …
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Understanding Heterogeneous Nucleation Mechanisms in Polyolefins
… are among the most widely used semi-crystalline polymers in the modern world, with many of their desirable properties due to their microstructure formed during crystallization. While processing conditions have a large impact on crystallization, an additional tool is the use of additives called …
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Synthesis, characterization, and mode I fracture toughness of aligned carbon nanotube polymer matrix nanocomposites
… based vertically-aligned carbon nanotube (A-CNT) polymer nanocomposites (A-PNCs) are manufactured. These A-PNCs can be tested to isolate structure-property relationships between the polymer matrix and the A-CNTs without the presence of the micro-scale fibers. Additionally, A-CNT volume fraction …
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The development of sub-micro filler enhanced polymer composites
Sub-micro silica flakes and graphite reinforced polymer composites have been developed in this research. The sub-micro polymer composites are designed to overcome problems associated with nanocomposite technology. Apart from the high cost of production, the other major problem in nanocomposites is …
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Formation and Characterisation of Nanostructured Polypyrrole Films: Their Growth on Membrane Supports and Application in Heavy Metal Remediation
… The removal of chromium by polypyrrole nanowires polymerised on conventional electrodes and on porous membranes was found to be initially enhanced by the application of a pre-reduction step which ensured that the polypyrrole was in its reduced state. After one hour immersion in an acidified …
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Multiscale characterization of mechanochemical reactions in mechanophore-crosslinked polymers under shear loading
… to impart productive mechanochemical response to polymeric materials. These mechanoresponsive materials possess the ability to respond to an applied global force through a local chemical reaction. In synthetic polymers, mechanochemical response is achieved through the use of a mechanophore, a …
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Magnetic polyamide 6 nanocomposites for increasing damage tolerance through self-healing of composite structures.
… a minimum. This work investigates Fe3O4 magnetic polymer nanocomposites that can be used to intrinsically heal composites through thermal stimuli, followed by self-healing of glass fibre reinforced polymer (GFRP) composites, which are fabricated by embedding the healable polymer nanocomposite as …
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