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Thienylenevinylene derived polymers have been extensively investigated for use in electrooptical devices. A precursor route and direct polymerisation methods to soluble thienylenevinylene homopolymers have been developed. These synthetic routes routinely yield little control of the polymer molar mass distribution and require further purification to remove the impurities and small oligomers. In this thesis, a new route to produce soluble polythienylenevinylenes is described via a ring-opening metathesis polymerisation (ROMP) it is extended to the preparation of PPV-PTV copolymers and block copolymers with a well-defined chain structure. Chapter 1 introduces the fundamentals of conjugated polymers and the general principle of the applications in organic light-emitting diodes and organic photovoltaic devices. The synthetic methods used to prepare poly(para-phenylenevinylene)s and poly(thienylenevinylene)s are introduced. Alkene metathesis is described and its use in ROMP examined. Chapter 2 focuses on the preparation and characterisation of poly(3,4-dialkylthienylenevinylene)s. Chapter 3 describes the preparation and characterisation of poly(para-phenylenevinylene-co-3,4-dioctylthienylenevinylene) copolymer. In Chapter 4, the preparation and characterisation of poly(para-phenylenevinylene)-block-poly(thienylenevinylene) copolymer are discussed. An overview of the work in this thesis and the potential for future work are presented in Chapter 5. All the experimental procedures are described in Chapter 6.

Block copolymers have been of great interest to the scientific community for a number of years as they offer a route to control polymer morphology, via self- assembly, at a level that is very difficult to achieve by other means. Coil-coil block copolymers have been extensively investigated and the physical properties of these polymers. are reasonably well understood both experimentally and theoretically. Rod-coil block copolymers are block copolymers in which one of the blocks acts as a rigid rod. Apart from scientific curiosity, one of the driving forces behind research into rod-coil block copolymers is the useful properties that some rod type polymers possess. One example of these properties is that of light emission from a semiconducting, conjugated rod. The first chapter introduces the preparation and properties of conjugated polymers and goes on to discuss block copolymers and the various morphologies that can be adopted. The second chapter describes the experimental work that was carried out in preparing rod- coil block copolymers for this thesis. The third chapter will concentrate on the synthesis and properties of the homopolymers that will be combined to form the final block copolymers. The fourth chapter discusses the preparation and physical properties of the block copolymers prepared, in particular those of poly(9,9-dioctylfluorene) and polydimethylsiloxane. The final chapter contains the overview and conclusion of this work and proposals for future endeavour.

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It is generally accepted that ion transport in polymer electrolytes is strongly coupled to the local viscosity of the host polymer and that, in most cases, appreciable ionic conductivity below the glass transition temperature is not observed.  Recent literature suggests that this may not always be the case and examples of polymer electrolytes exhibiting ionic conductivity decoupled from the polymeric motions have been reported.  This thesis investigates one such system, a liquid crystalline polymer electrolyte, which has been reported to show measurable conductivity in the sold phase.  The aim is to investigate such decoupled behaviour, how it may be optimised and to understand the conductivity mechanism.  The thermal, mechanical and electrical properties of lithium perchlorate and lithium triflate complexes of a liquid crystalline polymer and its non-liquid crystalline analogue have been investigated.  These studies suggest that the conductivity is not in fact decoupled from the local motions of the polymer.  Selected complexes are then examined further and conductivities measured under variable pressure.  From these data, activation energies, volumes and decoupling constants are calculated.  These results show that, although not fully coupled, these complexes cannot be considered to exhibit decoupled conductivity and, in fact, the non-liquid crystalline electrolytes actually show a greater tendency towards decoupled behaviour than their liquid crystalline counterparts.  In the final chapter, the two polymers are complexed with  lithium trifluoromethanesulphonyl imide, a salt that has been reported to give enhanced conducivities.  It is found that using this salt does indeed raise conductivities, but also reduces tendencies towards decoupled behaviour.

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