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This work reports the investigation of Cu-mediated polymerization systems and its limits, in order to obtain functional branched polymers, in particular star-shaped and graft-shaped polymers. A novel initiator structure has allowed developing a new approach to synthesise sequence controlled multiblock star polymers via Cu-mediated reversible deactivation radical polymerization (RDRP) in water. This technique allows the preparation of pentablock star shaped polymers in just under 90 minutes of reaction time. The obtained polymers had a good agreement between theoretical and experimental molecular weights and excellent control over molecular weight distribution. Alternatively, the Cu-mediated RDRP of star polymers using a British 1 penny coin was described, displaying similar results as in the literature, providing better experimental conditions. As the copper coin was recovered unharmed, the catalyst was found to be economically very effective. Furthermore, poly(2-ethyl oxazoline) (PEtOx) was polymerized with good control and partially hydrolysed to poly(ethylene imine) (PEI) to yield PEtOx-r-PEI using a microwave reactor. The secondary amines of PEI was converted to macroinitiators, to allow the polymerization of acrylamides in aqueous medium, resulting in graft type polymers based on a poly(oxazoline) backbone with acrylamide side chains. Finally, the synthesis of carbohydrate-monomers was described, which allows to obtain monomers with a different number of carbohydrates (one, two or three). These monomers were polymerised via aqueous SET-LRP, to explore their interaction with carbohydrate binding lectins and to understand the impact on binding of carbohydrate density on polymers and polymer chain length.

In der vorliegenden Arbeit wird die kationische Polymerisation neuer Furanmonomere beschrieben, die zu anorganisch-organischen Nanokompositen führt. Die kationische Polymerisation des Tetrafurfuryloxysilans steht dabei im Vordergrund. Ausgehend von den synthetisierten Kompositen wird die Herstellung von anorganischen Oxiden durch thermische Oxidation und von Kohlenstoffmaterialien durch thermische Behandlung in Schutzgasatmosphäre beschrieben. Die Charakterisierung der Komposite, Oxide und Kohlenstoffmaterialien erfolgt mittels Festkörper-NMR-Spektroskopie, Röntgenbeugung und Elektronenmikroskopie. Das Prinzip der neu entdeckten Zwillingspolymerisation wird vorgestellt und anhand verschiedener Beispiele auf seine weitere Anwendbarkeit zur Synthese anorganisch-organischer Kompositmaterialien überprüft.

This thesis studies the synthesis of diverse architectures of polymers via the reversible addition fragmentation chain transfer (RAFT) polymerisation process that is one of the most novel and versatile controlled polymerisation techniques. Star polymers, comb polymers, amphiphilic block copolymers, and random copolymers were utilised to fabricate porous films with hexagonal arrangement via a ???bottom-up??? engineering approach, namely a ???breath figure??? technique. The quality (i.e. pore regularity and pore size) of the films was optimised by controlling casting variables including humidity, airflow, concentration of polymer solution, polymer architecture, molecular weight of polymer, substrate, and casting volume. Porous membranes were chemically crosslinked to improve their mechanical strength if required. Furthermore, chemical surface modification of porous films was performed by grafting desired polymer (i.e. PNIPAAm or PAGA) via RAFT polymerisation. The RAFT groups present in the films play a role as anchoring sites for polymerisation, thus the complex initiator immobilising can be avoided in our system. The desired polymer grafting is able to enhance wettability and provide binding sites for adhesion and proliferation of cells. The topography of ungrafted and grafted films was analysed using optical microscopy, scanning electron microscopy, atomic force microscopy, confocal microscopy, ATR-FTIR, and XPS.

Radical polymerisation (RP) has for many years been an industrially important process, and the kinetics of the process remains an active area of research. As polymerisation proceeds, converting monomer (small molecules) into polymer (long chain molecules), chemical species of a variety of chain lengths are produced. Recent work has pointed toward the fact that rate coefficients for polymerisation reactions (specifically, termination and propagation) are often dependent on the chain-length of the reacting species. The focus of this thesis is to study the effects of chain-length-dependent reactions on the kinetics of RP, by using computer-based modeling and comparing the results of such modeling with experimental data. This enables the understanding of otherwise inexplicable trends and the building of more mechanistically detailed and accurate models for RP kinetics. In Chapter 2, a new model for termination is developed, connecting observations and analyses of termination kinetics at short chain lengths (particularly small molecule studies) with other observations and analyses at long chain lengths (conventional RP kinetics studies) in order to construct a model for termination that is shown to be capable of coherently describing termination kinetics at any chain length. In Chapter 3, this new model for termination is tested at short chain lengths on polymerisations with large quantities of added chain transfer agent. With the inclusion of chain-length-dependent propagation in the model, the model for termination is validated. Chapter 4 is aimed at extending an existing reduced-variable, compact, 'universal' description of steady-state RP kinetics by incorporating all known chain-length dependent reactivities. This both increases computational efficiency over other approaches and provides easily evaluated, approximate analytical expressions for RP kinetics. This foundational theory is applied in Chapter 5 to reach a deeper understanding of the behaviour of the model, and show how experimental data may readily be analysed to extract information about chain-length-dependent termination kinetics. In Chapter 6, the effect of chain-length dependent reactivities on the important technique of single-pulse pulsed-laser polymerisation is investigated, and this technique is validated as the best experimental method for investigation of termination kinetics. In general, a central result of this thesis is that chain-length-dependent reactivities, when acknowledged and properly incorporated into models, can explain many phenomena in RP kinetics which otherwise seem difficult to account for. No exceptions to this principle have been found.

Universiẗat-Gesamthochsch., Diss.--Paderborn, 1998.

Zugl.: Giessen, Universiẗat, Diss., 2008.

Zugl.: Giessen, Universiẗat, Diss., 2008.

Zugl.: Erlangen, Nürnberg, Univ., Diss., 2006

Stuttgart, Univ., Diss., 2001.