The kinetics of photopolymerizing systems are generally complicated by a variety of phenomena including autoacceleration, autodeceleration, primary cyclization, oxygen inhibition, reaction diffusion controlled termination, chain length dependent termination, and incomplete reaction of the double bonds. Each of these phenomena tends to confound the photopolymerization kinetics, making it difficult to predict the kinetics or ascertain exactly how changes in the reaction conditions will impact the polymerization kinetics and, ultimately, the polymer properties. The overall objective of this work is the thorough experimental characterization of these phenomena and the developments of a comprehensive theoretical model for describing the photopolymerization kinetics under a wide range of circumstances.

     Thus, this work focuses on experimental characterization of certain aspects of the kinetics and the development of an advanced, comprehensive model for predicting photopolymerization kinetics.

     Project Focus Summary:

• determining the effects of kinetic chain length and chain transfer reactions on the termination kinetic constant in crosslinked acrylic systems;

• determining the relative impacts of reactivity and dilution in copolymerization reactions by polymerizing in reactive diluents that have been hydrogenated; and

• developing and improving the model for photopolymerization kinetics to include the effects of temperature, heat transfer, and oxygen inhibition as well as all of the various kinetic features such as diffusion limited reactions, chain length dependent termination, and primary cyclization.