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 208 for “"Methyl methacrylate"”.
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Characterisation of Silsesquioxane-Poly(Methyl Methacrylate) blends
Silsesquioxanes are a novel hybrid material that have advantageous properties intermediate of polymers and ceramics, due to their inorganic-organic molecular structure. Current research has focused on the potential of this hybrid to enhance conventional materials. Through the incorporation of …
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Studies in the anionic polymerization of methyl methacrylate
… has been made of the anionic polymerization of methyl methacrylate using butyllithium and polystyryl lithium as initiators and using aluminium triisobutyl as a cocatalyst. The aspects of the polymerization that were examined were the effect of changing the order of addition of reagents, the …
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Ultrasonically initiated free radical catalyzed emulsion polymerization of methyl methacrylate
<p>"The emulsion polymerization of methyl methacrylate initiated by ultrasound has been studied at ambient temperature using sodium lauryl sulfate as the surfactant.</p> <p>The source of the free radical for the initiation process was found to come from the degradation of the sodium lauryl sulfate …
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Thermomechanical properties of polyhedral oligomeric silsequioxane- poly(methyl methacrylate) nanocomposites
Poly(methyl methacrylate)s (PMMA) containing polyhedral oligomeric silsesquioxane (POSS) nanoparticles (d [approx.] 1.5 nm) were subjected to heological, mechanical, and morphological tests to determine the effects that POSS has on the melt-state and solid-state properties of this commercially …
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Fracture-induced mechanophore activation and solvent healing in poly(methyl methacrylate)
… of SP-linked brittle polymers such as poly(methyl methacrylate) (PMMA), rubber nanoparticles can be incorporated into the matrix material. These nanoparticles facilitate the increased shear yielding necessary for SP activation during mechanical testing. Cross-linked SP-PMMA, containing 7.3 …
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An investigation of the radiation polymerization of methyl methacrylate-kaolin clay composites
… on the polymerization of a 50-50 weight mixture methyl methacrylate (MMA) kaolin clay system. The effect of dose rate (7.35 - 24.9 rads per second), temperature (25 to 75ºC) and total dose on the percentage conversion of monomer to polymer was studied. The rate of formation of polymer at 25ºC in …
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Highly Tough, Stiff, and Transparent Poly(Methyl Methacrylate) Composites Incorporating Thermoplastic Elastomer Nanofibrils
… are developed and incorporated into poly(methyl methacrylate) (PMMA) to fabricate polymer-polymer composites that are not only highly tough but also stiff and transparent. PMMA was chosen as the matrix material because of its brittle nature and tremendous commercial value. This thesis …
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Preparation of CO2-Switchable Poly(Methyl Methacrylate) Latexes by Surfactant-Free Emulsion Polymerization
… on the preparation of CO2 switchable poly(methyl methacrylate) latexes by surfactant-free emulsion polymerization. N,N-Dimethylaminoethyl Methacrylate (DMAEMA) was chosen as the functional comonomer to act as an in-situ generated surface active agent as well as the CO2 responsive agent. The …
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Optical and mechanical properties of glass fiber and ribbon reinforced poly(methyl methacrylate) composites
<p>"Composites with excellent optical clarity have been fabricated by matching the refractive index of the glass fiber reinforcement to that of the polymer matrix. Refractive index mismatch, resulting from temperature changes, leads to degradation of optical clarity in fiber composites due to light …
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Molecular and Cellular Mechanisms of the Angiogenic Effect of Poly(methacrylic acid-co-methyl methacrylate) Beads
Poly(methacrylic acid -co- methyl methacrylate) beads were previously shown to have a therapeutic effect on wound closure through the promotion of angiogenesis. However, it was unclear how this polymer elicited its beneficial properties. The goal of this thesis was to characterize the host response …
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Development of new dendritic ligands for copper mediated Atom Transfer Radical Polymerization (ATRP) of methyl methacrylate
… This led to the modification of DAB-(NH2)4 using methyl methacrylate to replace the peripheral amino groups of the DAB-(NH2)4 with tertiary amine groups. A second generation tertiary amine dendrimer was also synthesized in a similar fashion. The ligands obtained were then characterized using 13C …
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Stereocomplex poly (methyl methacrylate) fibers and self-reinforced composites and structural color of butterflies and beetles - characterization, replication and mimicry
Stereocomplex poly(methyl methacrylate) (PMMA) fibers for the purpose of reinforcing PMMA materials were developed. These kinds of composites are known as "self-reinforced" composites. We were successful in producing stereocomplex PMMA fibers with three different methods - wet spinning, gel …
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A thermo-mechanical finite deformation theory of plasticity for amorphous polymers : application to micro-hot-embossing of poly(methyl methacrylate)
… features of the mechanical response of poly(methyl methacrylate) in a temperature range spanning room temperature to 60C above the glass transition temperature #g 110C of the material, in a strain-rate range of 10-4/s to 10-1/s, and under compressive stress states in which this material does …
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Study of the phase behavior of poly(n-alkyl methacrylate-b-methyl methacrylate) diblock copolymers and its influence on the wettability of polymer surfaces
… of the phase behavior of poly(n-alkyl methacrylate-b-methyl methacrylate) diblock copolymers and its influence on the wettability of the polymer surfaces were carried out. For this investigation two polymethacrylic systems differing only in the alkyl rest of one block: poly(pentyl …
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Kr-F laser surface treatment of poly(methyl methacrylate), glycol-modified poly(ethylene terephthalate), and polytetrafluoroethylene for enhanced adhesion of Escherichia Coli K-12
… laser(248 nm) surface modification of poly(methyl methacrylate), glycol-modified poly(ethylene terephthalate), and polytetrafluoroethylene and its effect on the adhesion of Escherichia Coli K-12 bacteria. These three polymers were chosen for their very different mechanisms of ablation as …
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Atom transfer radical polymerisation - towards the synthesis of a fully-functional photorefractive polymer
… of the atom transfer radical polymerisation of methyl methacrylate at 90°C in diglyme solution initiated with ethyl-2-bromoisobutyrate and mediated by CuBr/N-octyl-2-pyridinemethanimine was studied and the orders of the reaction were established. The effect on the rate of polymerisation of the …
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Inter-Relationships Between Chemistry, Network Structure and Properties of Chain Growth Dimethacrylate Thermosets
Dimethacrylate oligomers diluted with styrene reactive diluents (so-called vinyl ester resins) are becoming increasingly important for composites in applications such as transportation vehicles, printed wiring boards and civil infrastructure. This research has focused on the generation and …
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Synthesis and characterisation of vinyl block copolymers
… has been made of the anionic polymerisation of methyl methacrylate using butyllithium and polystyryl lithium as initiators and the effects of lithium chloride and aluminium alkyls on the molecular weight and molecular weight distributions. Diblock copolymers of styrene-b-methyl methacrylate were …
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Respiratory exposure and potential dermal exposure to volatile organic compounds in nail salons : a pilot study
… nail technicians to acetone, formaldehyde, ethyl methacrylate, methyl methacrylate, toluene and xylene. Fifteen female nail technicians, working in different salons participated in this study. Products used for nail treatments differed between salons. Most salons used acrylate based nail products …
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