Kock J.B.L. de Chain-Length Dependent Bimolecular Termination in Free-Radical Polymerization: Theory, Validation and Experimental Application of Novel Model-Independent Methods

Eindhoven Technische Universiteit: Eindhoven. – 1999. - 218 p. Thesis. In this thesis, the chain-length dependence of termination reactions during free-radical polymerization has been investigated. After an extensive review of this field, provided in chapter 2, two novel kinetic analyses have been proposed in chapter 3, which should enable the direct and model-independent determination of the chain-length dependence of free-radical termination reactions. The first method is based upon the time-resolved measurement of the decay in the monomer concentration as a result of a single laser pulse. Again a single-pulse pulsed-laser technique is employed and the monodispersity assumption for the radical population is made, but now the resulting number molecular weight distribution (MWD) is subject to analysis. In order to evaluate the reliability of both theoretical ideas just mentioned, a number of assumptions needed to be validated. After having validated both methods theoretically, the experimental application of one of these methods, the one based on time-resolved single-pulse pulsed-laser polymerization, turned out to fail due to the inherent noise sensitivity of this method. In this thesis, the MWD method was applied to a homologous series of acrylates: methyl acrylate (MA), ethyl acrylate (EA) and butyl acrylate (BA). Summarizing the above, it can be concluded that single-pulse pulsed-laser polymerization techniques are amongst the most powerful techniques that are nowadays available to study the chain-length dependence of termination reactions. When using a dedicated kinetic analysis, as presented in this thesis, model-independent data for the chain-length dependence of kt can be obtained. These data allow for better predictions for the MWD of the final polymer product and so of the final product properties.Bimolecular Free-Radical Termination at Low Conversion
Determination of CLD Termination Rate Coefficients: Theory & Validation
Determination of CLD Termination Rate Coefficients: Experimental Results
EpilogueSamenvatting
Dankwoord
Curriculum Vitae