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Showing 1 to 20 of 27 for “"poly(propylene oxide)"”.
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Synthesis and characterization of poly(propylene oxide) and its copolymers
The synthesis of molecularly designed poly(propylene oxide) was accomplished by using aluminum porphyrin initiator/catalysts to prepare controlled molecular weights, narrow molecular weight distributions, topologies, and functionalities. Poly(propylene oxide) has been an important intermediate in …
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Polymer Stabilized Magnetite Nanoparticles and Poly(propylene oxide) Modified Styrene-Dimethacrylate Networks
… chloride salts in the presence of ammonium hydroxide at pH 9-10. One goal of this work has been to develop a generalized methodology for stabilizing nanomagnetite dispersions using well-defined, non-toxic, block copolymers, so that the resultant magnetite-polymer complexes can be used in a range …
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Hybrid Inorganic-Organic Materials: Novel Poly(Propylene Oxide) Based Ceramers, Abrasion Resistant Sol-Gel Coatings for Metals, and Epoxy-Clay Nanocomposites. With an Additional Chapter On: Metallocene Catalyzed Linear Polyethylene
… functionalized soft organic oligomer, poly(propylene oxide) (PPO), and tetramethoxysilane (TMOS). Despite the formation of covalent bonds between the inorganic and organic constituents, the resulting network materials were phase separated, composed of a silicate rich phase embedded in a …
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Synthesis, properties, and morphology of lignin based epoxy resins
Star-like lignin-poly(propylene oxide) copolymers were prepared by chain-extending steam exploded lignins (tulipifera liriodendron) with propylene oxide and by subsequent endcapping with ethylene oxide. Epoxidation of these copolymers was carried out with epichlorohydrin at room temperature, using …
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Multicomponent network and linear polymer systems: thermal and morphological characterization
Materials comprising of two or more polymeric components have achieved considerable technological significance in the last decade or so due to the unique properties often not attainable in their homopolymeric counterparts. In the present work, two such systemsone involving modified thermosets and …
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Nanostructured thermoset resins and nanocomposites containing hyperbranched blockcopolyether liquid rubbers and organophilic layered silicates
… layered silicates as well as functional liquid polymers of various architectures were used alone or in combination to tailor different properties, such as thermal stability, toughness or stiffness. Emphasis was also laid on easy processability of the resin systems. <br>Significant progress was …
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Application of PEO-PPO-PEO Triblock Copolymers in Synthesis of Silica and Organosilica Nanomaterials
… on the application of Pluronic triblock copolymers, poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO), in the synthesis of mesoporous material, such as double-helical silica nanotube structures as well as bridged organosilica nanotubes by using swollen micelles …
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PEO-PPO-PEO Surfactant Mixtures as Templates for Silicas With Very Large Cylindrical Mesopores at Ambient Temperature and With Helical Mesopores at Sub-Ambient Temperature
… the use of a mixed surfactant system of two poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) surfactants, with one of the copolymers containing a much larger percentage of hydrophobic (PPO) blocks than the employed co-surfactant. Systematic adjustments of experimental …
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High temperature nanofoams based on ordered polyamide matrices
Polyimides are one class of high temperature materials that have been extensively used in the microelectronics industry in passivation and protection. The extremely good thermal stabilities, along with desirable mechanical and electrical properties, have led to their use in integrated circuits and …
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PEO-containing copolymers as polyurethane soft segments in the development of high performance materials
Silk-inspired segmented polyurethanes containing flexible, hydrophilic segments with crystalline and liquid crystalline moieties were developed to mimic the hierarchical morphology of the continuous domain in and the superior mechanical properties of native spider silk. A series of polyurethane …
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Design, Synthesis, and Characterization of Magnetite Clusters using a Multi Inlet Vortex Mixer
… stabilized with an amphiphilic block copolymer. It outlines a method to design and form well-defined and colloidally stable magnetite clusters. A Multi Inlet Vortex mixer (MIVM) was used because it is a continuous process that yields particles with relatively narrow and controlled size …
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Amphiphilic linear-dendritic block copolymers for drug delivery
Polymeric drug delivery systems have been widely used in the pharmaceutical industry. Such systems can solubilize and sequester hydrophobic drugs from degradation, thereby increasing circulation half-life and efficacy. However, there are still challenges in the design of drug delivery vehicles to …
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Strategies for incorporating functional block copolymers into polyelectrolyte multilayer coatings
… (LbL) of temperature (T) responsive block copolymer - polyelectrolyte multilayers (PEMs). First, the LbL conditions that allow for temperature driven, large, reversible swelling transitions of multilayer constructs are determined. Use of weak polyelectrolyte components and selection of an …
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The Design of Stable, Well-Defined Polymer-Magnetite Nanoparticle Systems for Biomedical Applications
The composition and stability of polymer-magnetite complexes is essential for their use as a treatment for retinal detachment, for drug targeting and delivery, and for use as a MRI contrast agent. This work outlines a general methodology to design well-defined, stable polymer-magnetite complexes. …
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Synthesis and Characterization of Novel Magnetite Nanoparticle Block Copolymer Complexes
… with carboxylate-functionalized block copolymers, and aqueous dispersions of the complexes were investigated as functions of their chemical and morphological structures. The block copolymer dispersants possessed either poly(ethylene oxide), poly(ethylene oxide-co-propylene oxide), or …
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Development of Core-Shell Polymeric Nanostructures for Delivery of Diagnostic and Chemotherapeutic Agents
… complexes of anionic-nonionic block copolymers and cationic antibiotic aminoglycosides have been formed by electrostatic condensation. Amphiphilicity of the complexes was introduced into the shells by incorporating a hydrophobic poly(propylene oxide) segment into the block copolymer. …
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Investigation of the Influence of Selected Variables on the Solid State Structure-Property Behavior of Segmented Copolymers
Segmented copolymers are a commercially important class of materials that are utilized in a wide variety of applications. In these systems a relatively large number of variables such as backbone chemistry, segment molecular weight, and the overall molecular weight of the copolymer can be …
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Synthesis and characterization of high Tg nanofoams based on pyromellitic dianhydride and 1,1-bis(4-aminophenyl)-1-phenyl-2,2,2-trifluoroethane polyimide block and graft copolymers
Thermally stable polyimide block and graft copolymers with labile con1ponents (especially polypropylene oxide), have been prepared and investigated as low dielectric materials that afford desirable thermal, mechanical and electrical properties. Polyimide nanofoams based upon the controlled …
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Enabling Synthesis Toward the Production of Biocompatible Magnetic Nanoparticles With Tailored Surface Properties
Amphiphilic tri- and penta-block copolymers containing a polyurethane central block with pendant carboxylic acid groups flanked by hydroxyl functional polyether tails were synthesized. Our intention was to investigate the activities of these copolymers as dispersants for magnetite nanoparticles in …
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Effect of Encapsulated Species on Block Copolymer Micelle Self-Assembly
Due to their amphiphilic nature, block copolymers spontaneously form assemblies known as micelles in selective solvents. Minimization of the solution free energy drives the micellization process, with contributions from the polymer chains, surrounding solvent, and any additive molecules. Through …
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