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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 26 for “"Branched Polymers"”.
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Combinatorics and Modelling of Highly Branched Polymers
Highly branched polymers such as dendrimers and hyperbranched polymers have a found a variety of chemical applications owing to their unique structural and functional properties, but in many cases are still lacking sufficient theoretical characterization. This thesis takes marginal steps toward …
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Synthesis and Characterization of Multiphase, Highly Branched Polymers
… frequently cited as a key application for hyperbranched polymers. However, the high degree of branching in these polymers restricts entanglement and the resultant mechanical properties suffer. Longer distances between branch points may allow entanglements. Highly branched polymers, where linear …
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Synthesis and characterization of bis-MPA based branched polymers with thymine core
… and characterisation of the bis-MPA based branched materials was performed. Thymine derivative was incorporated into the polymer structure as a core moiety and an active centre for H-bonding. The formation of assemblies was investigated.
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Design and Synthesis of Polymer Networks and Branched Polymers for Triggered Deconstruction of Self-Assembly
… of free-standing self-assembling graft copolymers underpin enormous changes in material morphology and thermomechanical properties. Notably, we also introduce highly ordered body-centered-cubic morphologies which behave as soft plastic crystals, and lamellar morphologies which behave as …
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Single molecule studies of branched polymer dynamics
… of materials such as elasticity and wettability. Branched polymers exhibit strikingly different rheological behavior (e.g. enhanced stress dissipation and strain hardening) compared to linear polymers. In recent years, the dynamic properties of branched polymers have been studied using bulk …
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Single molecule studies of branched polymer dynamics in non-dilute solutions
The macroscopic properties of polymers are dictated by their molecular architecture and microstructure. Branched polymers exhibit a multitude of distinct rheological phenomena, such as shear thinning and enhanced strain hardening, compared to linear polymers as a direct consequence of their …
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Lattice Statistics Of Polymer Adsorption
The interaction of branched polymers with an adsorption surface is studied using rigorous and numerical methods. For a polymer network with a fixed topology and consisting of self-avoiding chains, we prove that the reduced free energy is the same as that for self-avoiding walks interacting with a …
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Constitutive modelling of branched polymer melts in non-linear response
… thesis is concerned with modelling long chain branched polymer melts using the McLeish and Larson Pompom constitutive equations. Usually the non-linear terms in this model are fitted to uniaxial extensional data due its sensitivity to levels of branching, but in this thesis I will study a …
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The synthesis, characterization and properties of new organometallic polymers
We have reviewed recent work on highly branched polymers called dendrimers. Two novel block copolymers consisting of organoruthenium dendritic wedges and linear polyethylene glycol blocks have been prepared. These new block copolymers have been characterized by IR, ¹H and ¹³C NMR, microanalysis, as …
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The Effects of Molecular Architecture on the Rheological and Mechanical Properties of Polymeric Systems
… on the surface segregation characteristics of branched polymers in blends with commercially available linear polymers were also investigated. In the blends of branched PEIs with polystyrene (PS), the surface migration of PEIs correlates with the changes in their molecular architecture with xAB. …
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The Influence of Branching and Intermolecular Interactions on the Formation of Electrospun Fibers
… were investigated for linear and randomly branched polymers. Empirical correlations were developed based on solution rheological measurements that predict the onset of electrospun fiber formation and average fiber diameter. In particular, for neutral, non-associating polymer solutions, the …
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The topology and electrical properties of nanoparticle networks
… data which was originally developed to describe branched polymers was shown to be applicable to the description of the networks of silicon particles. The milled particles which have a highly polydisperse size distribution, form agglomerates, which in turn cluster to form larger structures with a …
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Computational Studies of Polyetherimides: Beyond All-Atom Molecular Dynamics Simulations
… (MD) simulation is a useful tool to study polymers, but the accessible length and time scales are limited. In this thesis, we explore several computational methods that go beyond all-atom MD simulations to investigate polyetherimides. First, we have developed a transferable coarse-grained …
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Development of thermal field-flow fractionation for the characterization of hybrid nanoparticles and polymers with complex architecture
… for not only separation of nanoparticles and polymers but also as a characterization tool to obtain physiochemical distributions. Thermal FFF is unique as the separation mechanism is based on the differential transport of analytes in the presence of a temperature gradient. This thermophoresis …
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Synthesis and Characterization of Responsive Poly(Alkyl Methacrylate) Topologies
… and utilized in the synthesis of star-shaped polymers. Star polymer coupling was achieved by reacting the living poly(alkyl methacrylate) using 2,5-dimethyl-2,5-hexanediol dimethacrylate (DHDMA) or dicumyl dimethacrylate (DCDMA). These starshaped polymers were cleaved under hydrolytic …
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Uncovering and Exploiting Cucurbit[8]uril Host-Guest Dynamics in Bulk Mechanical Behaviour
… these reactive first guests created branched polymers with CB[8] rotaxanes, which formed gels upon mixing with hydroxyethyl cellulose (HEC) bearing pendant second guests. Lastly, the effect of different binding modes between guest molecules and CB[8] on gel behaviour was studied for …
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Synthesis and Characterization of Branched Macromolecules for High Performance Elastomers, Fibers, and Films
… A2 + B3 polymerization for the synthesis of hyperbranched polymers was altered using oligomeric precursors in place of either one or both of the monomer pairs to synthesize highly branched macromolecules. Unique topologies that are intermediates between long-chain branched and hyperbranched …
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Topology and Telechelic Functionality Control in Polyester Design
… have focused on synthesis of linear, long-chain branched, and novel crosslinked polyesters for applications spanning from pressure sensitive adhesives to biomedical applications. Altering polymer topology and functionality using different synthetic strategies was enabled tailoring the …
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Design, synthesis and characterization of fluorescent hyperbranched polyglycerols and organic nanoparticles with covalently bound anti-fading agents
… and anti-fading agent (AFA) moieties to hyperbranched polyglycerols (HPG). The use of HPGs as a scaffold to link fluorescein and anti-fading agents proved intractable, so a norbornyl based ROMP polymer was used instead. Through the iterative use of ROMP and RCM, organic nanoparticles (ONPs) …
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Branched Glycopolymers
Linear and branched glycopolymers of a sugar-carrying acrylate monomer, 3-O-acryloyl-1,2:5,6-di-O-isopropylidene-alpha-D-glucofuranose (AIGlc), were synthesized via atom transfer radical polymerization (ATRP). Self-condensing vinyl copolymerization (SCVCP) via ATRP was employed for the synthesis of …
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