Metal-containing polymers (MCPs) are emerging as a class of interesting materials with promising properties and functions. Although many techniques are available for their synthesis, the range of main-chain MCPs available for material applications is limited. Most well-defined main-chain MCP syntheses rely only on the ring-opening polymerization (ROP) of metallocene monomers, thereby new synthetic approaches for novel MCPs are in high demand. In this study a new polymerization technique, migratory insertion polymerization (MIP), was explored and used to produce novel types of MCPs with asymmetric iron repeat-units connected by phosphine-iron (Ph2P-Fe) and iron-acyl (Fe-CO) bonds in the backbone. This research work involved the synthesis, characterization and polymerization of cyclopentadienyl(dicarbonyl)(diphenylphosphinopropyl)iron (FpP). FpP consists of an Fp functional group capable of undergoing a migratory insertion reaction (MIR) and a phosphine group to assist the MIR. FpP was prepared via the reaction between cyclopentadienyl dicarbonyl iron metalate (Fp anion) and (3-chloropropyl)diphenylphosphine, and was characterized using Fourier transform infrared (FTIR), 1H NMR, 31P NMR, 13C NMR, and ultraviolet-visible (UV-Vis) spectroscopies. The molecules undergo intramolecular cyclization reactions at low concentrations in organic solvents, while polymerization occurs in bulk at 70°C, leading to polymers with number-average molecular weights (Mn) up to 12,000 g/mol and narrow molecular weight distributions (PDI=1.08-1.33). These polymers are soluble in a wide range of organic solvents and have a Tg of 100°C.

<p>Development in the field of materials science is propagated by the synthesis of polynuclear metal-containing complexes, that exhibit enhanced chemical and physical properties. This thesis describes the synthesis of new metal-containing linear polymers and dendritic molecules.</p> <p>Chapter 1 presents an overview of the field of metal-containing polymers, with particular attention to the synthesis of polymers via condensation polymerisation. This review includes the various types of metal-containing condensation polymers and the applications of these materials, where available. This discussion is followed by a brief summary of metal-containing dendrimers, which includes a concise description of their structure and applications in general.</p> <p>There are two routes to preparing metal-containing polymers. Chapter 2 describes the synthesis of three bifunctional organometallic monomers, of the general type [M]-O-{2,6-(CH2OH)2-4-CH3-C6H2}, where [M] represents the various metal-containing moieties, (&eta / 5-C5H5)(CO)2 Fe(CH2)3 (25), (&eta / 5-C5H4-CH2CH2CH2-)Re(CO)3 (26) and Fpdendr (27). These monomers were prepared using 2,6-bis(hydroxymethyl)-p-cresol as the key reagent. The monomers were used in classical polycondensation reactions with terephthaloyl chloride using ambient temperature solution techniques. This yielded new low molecular weight oligomeric polyesters, that were characterised using FTIR and 1HNMR spectroscopy, differential scanning calorimetry, thermogravimetric analysis and sizeexclusion chromatography.</p> <p>In Chapter 3, an alternate route to metal-containing polymers is described. In this case, bifunctional organic monomers were polymerised to give preformed organic polymers. Two types of organic polymers were prepared, viz. polyesters (with pendant vinyl moieties) and polyimines (with &alpha / -diimine units along the polymer backbone). Functionalisation of these preformed organic polymers with various metal sources was attempted. Hydrozirconation reactions of the vinyl polyesters with Schwartz&rsquo / s reagent, Cp2Zr(H)Cl, were attempted and were largely unsuccessful. Competing reactions with the ester functionality prevailed, preventing the desired reaction. Reaction of the polyimines with PdCl2(COD) yielded insoluble, intractable metal-containing oligomers. Partial characterisation of the complexes is described.</p> <p>The synthesis of new poly(propylene imine) iminopyridyl metallodendrimers is described in Chapter 4. Schiff-base condensation reaction of the commercially available DAB dendrimers with 2-pyridinecarboxaldehyde, gave the dendrimers 51, 52, and 53, with four, eight and sixteen pyridylimine functionalities respectively on the periphery. Successful complexation reactions with PdCl2(COD), PtCl2(COD) and CuCl2 produced the corresponding metal-containing dendrimers, with either PdCl2 (54, 55, 56), PtCl2 (57) or CuCl2 (58) moieties bound on the periphery. The metallodendrimers were insoluble in the more common organic solvents, and were characterised by IR and 1H-NMR spectroscopy and microanalysis where possible. Dendrimers with salicylaldiminato ligands on the periphery were prepared by reacting the DAB dendrimers with salicylaldehyde. These ligands were reacted with various metal acetates in an attempt to prepare new metalcontaining salicylaldimine dendrimers. This work yielded either paramagnetic metal complexes or insoluble, intractable compounds.</p> <p>Chapter 5 describes the applications of the catalyst precursors (54, 55, 56, 57, 58), discussed in Chapter 4, in the polymerisation of ethylene and the use of complexes 54 and 55 as Heck cross-coupling catalyst precursors. The complexes all showed catalytic activity toward ethylene polymerisation. A discussion of their activity, the polyethylene molecular weight and microstructure is presented in this chapter. The precursors 54 and 55 are also effective catalysts in the Heck reactions, coupling iodobenzene with methyl acrylate, styrene and 1-octene in high conversions.</p> <p>General conclusions are given in Chapter 6.</p>

Metal-containing polymers (MCPs) are emerging as a class of interesting materials with promising properties and functions. Although many techniques are available for their synthesis, the range of main-chain MCPs available for material applications is limited. Most well-defined main-chain MCP syntheses rely only on the ring-opening polymerization (ROP) of metallocene monomers, thereby new synthetic approaches for novel MCPs are in high demand. In this study a new polymerization technique, migratory insertion polymerization (MIP), was explored and used to produce novel types of MCPs with asymmetric iron repeat-units connected by phosphine-iron (Ph2P-Fe) and iron-acyl (Fe-CO) bonds in the backbone. This research work involved the synthesis, characterization and polymerization of cyclopentadienyl(dicarbonyl)(diphenylphosphinopropyl)iron (FpP). FpP consists of an Fp functional group capable of undergoing a migratory insertion reaction (MIR) and a phosphine group to assist the MIR. FpP was prepared via the reaction between cyclopentadienyl dicarbonyl iron metalate (Fp anion) and (3-chloropropyl)diphenylphosphine, and was characterized using Fourier transform infrared (FTIR), 1H NMR, 31P NMR, 13C NMR, and ultraviolet-visible (UV-Vis) spectroscopies. The molecules undergo intramolecular cyclization reactions at low concentrations in organic solvents, while polymerization occurs in bulk at 70°C, leading to polymers with number-average molecular weights (Mn) up to 12,000 g/mol and narrow molecular weight distributions (PDI=1.08-1.33). These polymers are soluble in a wide range of organic solvents and have a Tg of 100°C.

<p>Development in the field of materials science is propagated by the synthesis of polynuclear metal-containing complexes, that exhibit enhanced chemical and physical properties. This thesis describes the synthesis of new metal-containing linear polymers and dendritic molecules.</p> <p>Chapter 1 presents an overview of the field of metal-containing polymers, with particular attention to the synthesis of polymers via condensation polymerisation. This review includes the various types of metal-containing condensation polymers and the applications of these materials, where available. This discussion is followed by a brief summary of metal-containing dendrimers, which includes a concise description of their structure and applications in general.</p> <p>There are two routes to preparing metal-containing polymers. Chapter 2 describes the synthesis of three bifunctional organometallic monomers, of the general type [M]-O-{2,6-(CH2OH)2-4-CH3-C6H2}, where [M] represents the various metal-containing moieties, (&eta / 5-C5H5)(CO)2 Fe(CH2)3 (25), (&eta / 5-C5H4-CH2CH2CH2-)Re(CO)3 (26) and Fpdendr (27). These monomers were prepared using 2,6-bis(hydroxymethyl)-p-cresol as the key reagent. The monomers were used in classical polycondensation reactions with terephthaloyl chloride using ambient temperature solution techniques. This yielded new low molecular weight oligomeric polyesters, that were characterised using FTIR and 1HNMR spectroscopy, differential scanning calorimetry, thermogravimetric analysis and sizeexclusion chromatography.</p> <p>In Chapter 3, an alternate route to metal-containing polymers is described. In this case, bifunctional organic monomers were polymerised to give preformed organic polymers. Two types of organic polymers were prepared, viz. polyesters (with pendant vinyl moieties) and polyimines (with &alpha / -diimine units along the polymer backbone). Functionalisation of these preformed organic polymers with various metal sources was attempted. Hydrozirconation reactions of the vinyl polyesters with Schwartz&rsquo / s reagent, Cp2Zr(H)Cl, were attempted and were largely unsuccessful. Competing reactions with the ester functionality prevailed, preventing the desired reaction. Reaction of the polyimines with PdCl2(COD) yielded insoluble, intractable metal-containing oligomers. Partial characterisation of the complexes is described.</p> <p>The synthesis of new poly(propylene imine) iminopyridyl metallodendrimers is described in Chapter 4. Schiff-base condensation reaction of the commercially available DAB dendrimers with 2-pyridinecarboxaldehyde, gave the dendrimers 51, 52, and 53, with four, eight and sixteen pyridylimine functionalities respectively on the periphery. Successful complexation reactions with PdCl2(COD), PtCl2(COD) and CuCl2 produced the corresponding metal-containing dendrimers, with either PdCl2 (54, 55, 56), PtCl2 (57) or CuCl2 (58) moieties bound on the periphery. The metallodendrimers were insoluble in the more common organic solvents, and were characterised by IR and 1H-NMR spectroscopy and microanalysis where possible. Dendrimers with salicylaldiminato ligands on the periphery were prepared by reacting the DAB dendrimers with salicylaldehyde. These ligands were reacted with various metal acetates in an attempt to prepare new metalcontaining salicylaldimine dendrimers. This work yielded either paramagnetic metal complexes or insoluble, intractable compounds.</p> <p>Chapter 5 describes the applications of the catalyst precursors (54, 55, 56, 57, 58), discussed in Chapter 4, in the polymerisation of ethylene and the use of complexes 54 and 55 as Heck cross-coupling catalyst precursors. The complexes all showed catalytic activity toward ethylene polymerisation. A discussion of their activity, the polyethylene molecular weight and microstructure is presented in this chapter. The precursors 54 and 55 are also effective catalysts in the Heck reactions, coupling iodobenzene with methyl acrylate, styrene and 1-octene in high conversions.</p> <p>General conclusions are given in Chapter 6.</p>

Yes / Amphiphilic nucleobase-containing block copolymers with poly(oligo(ethylene glycol) methyl ether methacrylate) as the hydrophilic block and nucleobase-containing blocks as the hydrophobic segments were successfully synthesized using RAFT polymerization and then self-assembled via solvent switch in aqueous solutions. Effects of the common solvent on the resultant morphologies of the adenine (A) and thymine (T) homopolymers, and A/T copolymer blocks and blends were investigated. These studies highlighted that depending on the identity of the common solvent, DMF or DMSO, spherical micelles or bicontinuous micelles were obtained. We propose that this is due to the presence of A–T interactions playing a key role in the morphology and stability of the resultant nanoparticles, which resulted in a distinct system compared to individual adenine or thymine polymers. Finally, the effects of annealing on the self-assemblies were explored. It was found that annealing could lead to better-defined spherical micelles and induce a morphology transition from bicontinuous micelles to onion-like vesicles, which was considered to occur due to a structural rearrangement of complementary nucleobase interactions resulting from the annealing process. / European Research Council (ERC), University of Warwick, Engineering and Physical Sciences Research Council (EPSRC), National Science Foundation (U.S.) (NSF)

Yes / Herein, we report the preparation of nucleobase-containing synthetic amphiphilic diblock copolymers using RAFT polymerization. Well-defined spherical micelles can be formed in aqueous solutions through the self-assembly of the amphiphilic copolymers, with the nucleobase functionality sequestered in the core of the particles. Following assembly, copolymers with the complementary nucleobase were introduced into the preformed micellar solutions. This addition induced a change in nanostructure size and morphology and this reorganization was fully characterized by DLS, TEM, SLS and SAXS analysis. The insertion of copolymers with the complementary nucleobase into formed micelles was also confirmed by 1 H NMR and UV-vis spectroscopy. For micelles consisting of moderately short hydrophobic blocks, upon the addition of complementary nucleobase copolymer a decrease in size was observed but without any accompanying morphological change. For micelles formed from longer hydrophobic blocks, a morphological transition from spheres to cylinders and then to smaller spheres was observed upon increasing the amount of the complementary copolymer. This work highlights how complementary nucleobase interactions can be used to induce nanostructure reorganization and through a simple mixing process provide access to different nanostructure sizes and morphologies. / University of Warwick, China Scholarship Council (CSC), National Science Foundation (U.S.) (NSF), Engineering and Physical Sciences Research Council (EPSRC), European Research Council (ERC)

Philosophiae Doctor - PhD / metal-containing complexes, that exhibit enhanced chemical and physical properties. This thesis describes the synthesis of new metal-containing linear polymers and dendritic molecules. Chapter 1 presents an overview of the field of metal-containing polymers, with particular attention to the synthesis of polymers via condensation polymerisation. This review includes the various types of metal-containing condensation polymers and the applications of these materials, where available. This discussion is followed by a brief summary of metal-containing dendrimers, which includes a concise description of their structure and applications in general. There are two routes to preparing metal-containing polymers. Chapter 2 describes the synthesis of three bifunctional organometallic monomers, of the general type [M]-O-{2,6-(CH2OH)2-4-CH3-C6H2}, where [M] represents the various metal-containing moieties, (η5-C5H5)(CO)2 Fe(CH2)3 (25), (η5-C5H4-CH2CH2CH2-)Re(CO)3 (26) and Fpdendr (27). These monomers were prepared using 2,6-bis(hydroxymethyl)-p-cresol as the key reagent. The monomers were used in classical polycondensation reactions with terephthaloyl chloride using ambient temperature solution techniques. This yielded new low molecular weight oligomeric polyesters, that were characterised using FTIR and 1HNMR spectroscopy, differential scanning calorimetry, thermogravimetric analysis and sizeexclusion chromatography. In Chapter 3, an alternate route to metal-containing polymers is described. In this case, bifunctional organic monomers were polymerised to give preformed organic polymers. Two types of organic polymers were prepared, viz. polyesters (with pendant vinyl moieties) and polyimines (with α-diimine units along the polymer backbone). Functionalisation of these preformed organic polymers with various metal sources was attempted. Hydrozirconation reactions of the vinyl polyesters with Schwartz’s reagent, Cp2Zr(H)Cl, were attempted and were largely unsuccessful. Competing reactions with the ester functionality prevailed, preventing the desired reaction. Reaction of the polyimines with PdCl2(COD) yielded insoluble, intractable metal-containing oligomers. Partial characterisation of the complexes is described. The synthesis of new poly(propylene imine) iminopyridyl metallodendrimers is described in Chapter 4. Schiff-base condensation reaction of the commercially available DAB dendrimers with 2-pyridinecarboxaldehyde, gave the dendrimers 51, 52, and 53, with four, eight and sixteen pyridylimine functionalities respectively on the periphery. Successful complexation reactions with PdCl2(COD), PtCl2(COD) and CuCl2 produced the corresponding metal-containing dendrimers, with either PdCl2 (54, 55, 56), PtCl2 (57) or CuCl2 (58) moieties bound on the periphery. The metallodendrimers were insoluble in the more common organic solvents, and were characterised by IR and 1H-NMR spectroscopy and microanalysis where possible. Dendrimers with salicylaldiminato ligands on the periphery were prepared by reacting the DAB dendrimers with salicylaldehyde. These ligands were reacted with various metal acetates in an attempt to prepare new metalcontaining salicylaldimine dendrimers. This work yielded either paramagnetic metal complexes or insoluble, intractable compounds. Chapter 5 describes the applications of the catalyst precursors (54, 55, 56, 57, 58), discussed in Chapter 4, in the polymerisation of ethylene and the use of complexes 54 and 55 as Heck cross-coupling catalyst precursors. The complexes all showed catalytic activity toward ethylene polymerisation. A discussion of their activity, the polyethylene molecular weight and microstructure is presented in this chapter. The precursors 54 and 55 are also effective catalysts in the Heck reactions, coupling iodobenzene with methyl acrylate, styrene and 1-octene in high conversions. / South Africa

No description available.

Polymeric materials with inherent stimulus response represent an ever-growing area of research. In particular, block copolymers demonstrate exciting properties owing to their enhanced mechanical strength and microphase separation. Incorporating functionality into block copolymers proves useful in enhancing their utility. Presently, synthesis and subsequent post-polymerization modification achieved this for a range of block copolymers. In particular, neutralization of acid-containing polymers readily imparted ionic functionality and yielded microphase-separated block copolymer domains, enhancing polymer thermomechanical properties and ion transport. An ABA triblock copolymer composed of mechanically reinforcing polystyrene outer blocks and ionic central poly(1-methylimidazolium acrylate) block acted as a host for ionic liquid that caused an evolution in bulk morphology, resulting in enhanced ionic conductivity. The resulting membrane also exhibited a strong electromechanical actuation response under applied potential. Adding ionic liquid doped with a corresponding lithium salt enabled evaluation of sulfonated block copolymers as components of ternary polymer electrolytes, relevant for battery applications. Modification of a sulfonic acid-containing pentablock copolymer presented photocurable functional groups to the ionic domains which enabled their UV irradiation-induced curing. This novel route of modifying ion-containing block copolymers resulted in enhanced thermomechanical properties and enabled healing of physical defects in the film, unprecedented for ion-containing block copolymers. Covalent networks represent a relevant area of research for a wide variety of applications such as coatings, adhesives, and scaffolds. Careful design of degradable crosslinkers enables stimulus response in these networks by eliminating covalent crosslinks and affording a soluble product. Extension of poly(ethylene glycol) methacrylate-based network formation into three dimensions using microstereolithography resulted in novel acid-degradable 3D-printed parts. An additional study investigated mixtures of acrylamide-modified poly(vinyl alcohol) and poly(ethylene glycol) diacrylate as water-soluble resins for the direct formation of hydrogels from solution. Photorheology and photocalorimetry investigated the thermal and mechanical changes inherent in the curing process and evaluated the mixtures as a platform for microstereolithography. / Ph. D.

Yes / The synthesis of nucleobase-containing polymers was successfully performed by RAFT dispersion polymerization in both chloroform and 1,4-dioxane and self-assembly was induced by the polymerizations. A combination of scattering and microscopy techniques were used to characterize the morphologies. It is found that the morphologies of self-assembled nucleobase-containing polymers are solvent dependent. By varying the DP of the core-forming block, only spherical micelles with internal structures were obtained in chloroform when using only adenine-containing methacrylate or a mixture of adenine-containing methacrylate and thymine-containing methacrylate as monomers. However, higher order structures and morphology transitions were observed in 1,4-dioxane. A sphere-rod-lamella-twisted bilayer transition was observed in this study. Moreover, the kinetics of the dispersion polymerizations were studied in both solvents, suggesting a different formation mechanism in these systems. / University of Warwick, Swiss National Science Foundation, EPSRC, Birmingham Science City, Advanatfe West Midlands (AWM), European Regional Development Fund (ERDF), Science City Research Alliance, Higher Education Funding Council for England (HEFCE)