(241b) Initial Rate Kinetics of Pyrene Polymerization Catalyzed with AlCl3
Oligomers of Polycyclic aromatic hydrocarbons (PAHs) have been shown to be ideal precursors for liquid crystalline materials, due to the ability of specific oligomers to form an ordered mesophase. This feature gives them excellent heat and charge transfer properties, which are ideal for many applications, including very high thermal conductivities. In our research group, we have done a lot of work with the PAH pyrene. In that work, pyrene was catalytically reacted to form pyrene oligomers, which were then fractionated for individual property testing. During that testing, we found that the pyrene trimer oligomer was able to form 100% liquid crystalline mesophase, making it the lowest melting point mesophase ever discovered. In order to better understand the reactions taking place in this system so that trimer production could be maximized, we sought to model the kinetics which governed the system of reactions. Some work had already been done in a large reactor that was mass-transfer limited, where we modeled the kinetics of our system once it had reached temperature. However, long, but necessary heat-up times (2-3 hours) prevented us from modeling the initial reactions taking place in our system. To overcome this, we have developed a technique which allows us to reduce our heat-up time form 2-3 hours to about 5 minutes. This allows us to finally obtain kinetic data describing the initial reactions taking place in this system and has enabled us to determine the conditions for maximizing pyrene trimer formation. Using the kinetic data obtained, a kinetic model was proposed and rate constants, activation energies, and pre-exponential factors were obtained for this system of reactions.