| Photopolymerization provides the means for producing a wide variety of polymeric materials ranging from high and low molecular weight linear polymers to highly crosslinked, glassy polymer networks. Photopolymerizations are prevalent due to the diverse range of monomers that can be homo- or copolymerized using common photocuring techniques. Furthermore, since the reaction proceeds only in areas that are exposed to light, photopolymerization allows facile control of the reaction both spatially and temporally. However, many polymerizations are carried out in a solvent-free state, and effects rising from increased viscosity and vitrification can complicate the reaction kinetics immensely. To control these polymerizations, the kinetics must be well characterized with respect to both the environmental conditions in which the polymerization is carried out and the inherent kinetic behavior imparted by the choice of monomer(s).;To move toward the goal of describing polymerization behavior in complex systems, a homogeneous kinetic model was created to predict the polymerization kinetics of both monovinyl and multifunctional monomers. An analytical method was developed simultaneously to provide the required kinetic parameters from a single experimental polymerization rate profile. The predictions of the homogeneous kinetic model were then compared to rate profiles found using differential scanning calorimetry to verify the validity of both the kinetic model and the parameter determination method. The model was extended to account for primary radical termination, and it was demonstrated that such model serves as a useful tool for investigating effects that are difficult to reproduce in the laboratory.;The pinnacle of this work was the development of a comprehensive kinetic model to predict the polymerization rate behavior in thick samples. This model, which was based on the homogenous kinetic model, accounts for mass transfer, heat transfer, and light attenuation throughout the thickness of the film. Inhibitor and solvent effects were also included in the comprehensive model. Upon its development, the model was used to predict polymerization kinetics for systems in which oxygen inhibition, monomer and solvent diffusion, and heat transfer effects are pronounced. The model was also used to describe complex polymerization behavior in industrial and novel photopolymerization processes, such as the production of soft contact lenses and holographic liquid crystal diffraction gratings. |
