A systematic study on the effect of molecular structure on the photoinitiated polymerization of acrylates was undertaken. Initially, the research was focused on the effect of hydrogen bonding, and it was found that preorganization via hydrogen bonding enhances the maximum rate of polymerization (R p). This hydrogen bonding facilitated preorganization also affected the tacticity of the resultant polymer. Next, the effect of polarity as represented by the calculated dipole moment (μcalc) of a given monomer was investigated. A direct linear correlation between R p and the calculated Boltzmann-averaged dipole moment (μcalc) was observed. The R p−μcalc correlation holds for pure monomers, mixtures of monomers, and even mixtures of monomers with inert solvents. This correlation enables the rational design of monomers with a required reactivity. In addition, these studies suggest that the propagation step of polymerization is influenced by hydrogen bonding while the dipole moment influences the termination rate constant. These two mechanistic explanations can be regarded as complementary factors that influence the speed of acrylate polymerization.

Enzymatic ring-opening polymerization was applied to synthesize high molecular weight polypentadecalactone (PPDL). The synthetic procedure was optimized on a small-scale and subsequently transferred to 30 g scale to yield sufficient material for fiber spinning. Molecular weights (Mw) of 143 000 g mol(-1) were obtained. Mechanical and thermal properties of the non-oriented, high molecular weight PPDL were determined and are largely in agreement with the literature data. The high molecular weight PPDL was melt-processed into fibers, which were further elongated to about 9-10 times their original length. Analysis of the fibers revealed differences in crystal orientation as a function of the processing conditions. Preliminary fiber tensile measurements confirm a high strength of up to 0.74 GPa for the fiber with the highest crystal orientation

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