Abstract
Chapter One of this thesis describes the nature of the problem under investigation, viz an inability to control functionality number and type in phenylether-formaldehyde condensations, a review of the relevant literature, and the use of phenoxybenzyl monomers as a means to determine the reaction mechanism. Chapter two describes the first syntheses and the syntheses used in this thesis of the phenoxybenzyl monomers used. Chapter three contains an outline of the reaction techniques used and describes the analytical methods used in this thesis, namely gel permeation chromatography (GPC) and carbon-13 nuclear magnetic resonance (13C NMR) . In Chapter four the rates of oligomerisation of the hydroxy monomers under acid catalysis are measured, as is the rate when acetic acid is added as a reactive diluent. The effect of catalyst to monomer ratio is described, and the differences between the systems discussed with the aid of basicity data. Chapter five commences with an assignment of the peaks observed in carbon-13 NMR spectra for the phenoxybenzyl monomers and of other species thought to be present during their oligomerisation reactions. It goes on to produce time-concentration profiles of the reactive intermediates (via 13C NMR measurements) present during the reaction discussed in chapter four. Important differences are seen when acetic acid diluent is present in terms of controlling functionality type. Chapter 6 discusses attempts at controlling multi-substitution in polybenzyls before describing a technique useful in the phenoxybenzyl system for preventing this occurring. The same technique holds good when dihydroxy functional monomers are added, allowing control of the number of functional groups per oligomer chain. Chapter 7 describes the use of GPC to assess the rate of monomer reactions in the systems researched in chapters four and five. Orders of reaction are determined and kinetic expressions derived. The experimental methods and techniques used are described in detail in chapter 8, which concludes with references.