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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 62 for “"Ring-opening polymerization"”.
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The cationic ring-opening polymerization of cyclic ethers
The kinetics and mechanisms of ring opening polymerization and copolymerizntion of different cyclic ethers were studied using mainly a cationic system of iinitiation. BF30Et2/ethanediol. The cyclic ethers reacted differently showing that ring strain and basicity are the main driving forces in …
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Macrocyclic Monomers: Synthesis, Characterization and Ring-opening Polymerization
… discovery of high yield synthesis and facile ring-opening polymerization of cyclic polycarbonate; the need for a technique to solve the tough processibility problem of high performance polymers. This work was intended to address the following aspects in the cyclic poly(ether ketone) or sulfone …
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The ring opening polymerization of ring strained cyclic ethers
The kinetics and mechanisms of the ring-opening polymerization of oxetane were studied using cationic and coordinated anionic catalysts. The cationic initiators used were BF30Et2!/ethanol, BF30Et2!/ethanediol and BF30Et2/propantriol. Kinetic determinations with the BF30Et2/diol system indicated …
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Development of Controlled Ring-Opening Polymerization of O-Carboxyanhydrides
… to summarize my research on the development of ring-opening polymerization (ROP) of O-carboxyanhydrides (OCAs) to synthesize functionalized, degradable polyesters. Biodegradable polyesters are promising alternatives to conventional petroleum-based non-degradable polyolefins and they are widely …
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Synthesis of functionalized polyamide 6 by anionic ring-opening polymerization
… a functionalizable primary amine) via anionic ring-opening polymerization. By using this strategy, we describe: (i) the synthesis of thermally more stable fluorinated polyamide 6 having a hydrophobic surface; (ii) the synthesis of polyamides 6 bearing pendant cinnamoyl groups, which are thermo- …
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Indium complexes and their role in the ring-opening polymerization of lactide
… of a series of chiral indium complexes bearing a tridentate NNO ligand are reported. The ligand 2-[[[(dimethylamino)cyclohexyl]amino]methyl]- 4,6-bis(tert-butyl) phenol (H₂NNO) was synthesized via a previously published procedure and bound to indium by both a protonolysis and salt …
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Synthesis of Functionalized Sustainable Polyesters via Controlled Ring-opening Polymerization of O-carboxyanhydrides
… have been developed by means of controlled ring-opening polymerization of O-carboxyanhydrides mediated by a highly redox reactive manganese complex and a zinc-alkoxide. Mechanistic studies indicated that the ring-opening process proceeded via the Mn-mediated decarboxylation with alkoxy …
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Part I: Synthesis and Ring Opening Polymerization of Macrocyclic Monomers for Production of Engineering Thermoplastics
… ether macrocycles ranging from 30 to 60 atom ring sizes were synthesized in good yields (up to 83%) by the two component method under high dilution conditions. These macrocycles have unsymmetric structures containing sulfone/ketone or sulfone/phosphine oxide functional groups and have …
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Design, Synthesis and Application of Novel Degradable Materials Based on Polyesters by Radical Ring-Opening Polymerization
… material based on polyesters by radical ring-opening polymerization (RROP) were described in this thesis. Herein, we studied a rare example of the formation of polystyrene-grafted aliphatic polyester in one-pot by radical polymerization including the reaction mechanism, designed …
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The ring-opening polymerization of cyclosiloxanes in the presence of bis ([alpha], [omega]-aminopropyl)-1,3-tetramethyldisiloxane
The ring-opening polymerization of octamethylcyclotetrasiloxane, D₄ , in the presence of bis(α,ω-aminopropyl)-1,3-tetramethyldisiloxane using potassium siloxanolate and tetramethylammonium siloxanolate catalysts has been investigated. The use of reversed-phase high performance liquid chromatography …
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Well-defined molecular brushes: Synthesis by a "grafting through" strategy and self assembly into complicated hierarchical nanostructures
… is achieved by combining orthogonal living polymerization techniques rationally, such as living/controlled radical polymerization, ring opening polymerization and ring opening metathesis polymerization. Generally, the strategy can be divided into two steps: the first step involves the …
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Bimetallic Main-Group Catalysts for the Synthesis of Advanced Biocompatible, Biodegradable, and Sustainable Polymers
… complexes were employed as catalysts in the ring-opening polymerization (ROP) of lactide. Furthermore, both random and block copolymerizations of lactide with ε-caprolactone were carried out to achieve control over polymer microstructure and properties. In addition, this dissertation explores …
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The synthesis of nanoporous hydrogels using sacrificial block copolymers
… The triblock copolymer was produced by the ring opening polymerization of c-caprolactone with PEO as a macro-initiator in the presence of stannous octoate as a catalyst.
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Synthesis of novel siloxane-containing block and graft copolymers by anionic polymerization and the macromonomer technique
… possible. The anionic alkyl- lithium initiated ring opening polymerization of the hexamethylcyclotrisiloxane has been investigated to prepare polymers of controlled molecular weights and narrow molecular weight distributions. This technique was extended to the preparation of macromonomers and …
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Rapid, Efficient and Versatile Strategies for Functionally Sophisticated Polymers and Nanoparticles: Degradable Polyphosphoesters and Anisotropic Distribution of Chemical Functionalities
… polymers synthesized by organocatalyzed ring-opening polymerizations, and two polyphosphoester-based nanoparticle systems for various biomedical applications.</p><p>Inspired by the many hierarchical assembly processes that afford complex materials in Nature, the construction of …
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Design of Functional Benzoxazine Materials Via Thiol-Mediated Reactions
… of the benzoxazine to undergo heat-induced ring-opening polymerization, adjusting the properties of the networks by varying the functionality of the thiol. The kinetics of the thiol-benzoxazine reaction were determined to compete with thiol-alkyne polymerization, and so the properties of the …
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Amino acid N-carboxyanhydrides and polypeptides: Controlled polymerization, properties and applications
… Ph.D. research is to develop controlled/living polymerization techniques of α-amino acid N-carboxyanhydrides (NCAs) and synthetic polypeptides based materials. Polypeptides are a class of emerging biomaterials receiving increasing interests for various applications including drug delivery, gene …
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Synthetic polypeptide-based hydrogel systems for biomaterials
… formed from synthetic polypeptides generated by ring opening polymerization (ROP) of a-amino acid N-carboxyanhydrides (NCAs) present a robust material for modeling the interaction between extracellular matrix (ECM) properties and cellular phenomena. The unique properties of the polypeptide …
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